Florida State University Libraries

Electronic Theses, Treatises and Dissertations The Graduate School

2017 Non-Aqueous Transuranic Coordination Complexes Shane S. Galley

Follow this and additional works at the DigiNole: FSU's Digital Repository. For more information, please contact [email protected] FLORIDA STATE UNIVERSITY

COLLEGE OF ARTS AND SCIENCES

NON-AQUEOUS TRANSURANIC COORDINATION COMPLEXES

SHANE S. GALLEY

A Dissertation submitted to the Department of Chemistry and Biochemistry in partial fulfillment of the requirements for the degree of Doctor of Philosophy

2017

Shane S. Galley defended this thesis on November 13, 2017 The members of the supervisory committee were:

Thomas E. Albrecht-Schmitt Professor Directing Dissertation

Vladimir Dobrosavljevic University Representative

Kenneth Hansom Committee Member

Michael Shatruk Committee Member

The Graduate School has verified and approved the above-named committee members, and certifies that the dissertation has been approved in accordance with university requirements.

This is dedicated to my family at Hot Yoga Tallahassee. Thank you for the love and support. May the light in me, Honor the light in you. Namaste

iii

ACKNOWLEDGMENTS

First, I would like to thank my Family. My parents, Kevin and Gia, and Grammy for all the support they provide throughout this journey. Even though you were 1000 miles away, it was comforting knowing you were there when I needed you guys. A huge shout out to my sister Samantha and baby Layla, for all the visits and distractions. Having you guys in the same state this past year was awesome. Thank you for being there though the good and the bad. And Michael, as you have been with me since my second year of grad school. Thank you for all the love, support, and dealing with all my Amanda Bynes/2007 Britney Spears breakdowns. I would like to thank my advisor, Dr. Thomas E. Albrecht-Schmitt. You have given me the support, guidance and amazing opportunities to succeed and be the best I can be. I am sincerely grateful for all that you have done for me. Also, thanks for not throwing me out the fifth story window, that fall wouldn’t have been pleasant. I am very appreciative for all the Schminions that I have gotten to work with over the course of my graduate school career. I would especially like to thank Samantha Cary for being my beacon in the lab and my favorite coffee date. Unfortunately, I will not be following you to Los Alamos. Ali Arico for being on this journey with me from Day 1 but a week late. Of course my lovely undergrads, Cayla, Mia, and Jacob. Thank you for letting me mentor you over the past years and accomplishing some great work! Maybe one day all our ducks will be in a row. A huge shout goes to my academic step parents, Stosh Kozimor and Suzanne Bart. Stosh, for your knowledge/techniques in actinide chemistry along with the lovely nights at the SLAC. Suzanne for collaborating, advising, and challenging my synthetic chemistry of the actinides. Last, I would like to thank Florida State University for allowing me to do this work. The Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Sciences, Office of Science, Heavy Elements Chemistry Program, U.S. Department of Energy, under Grant DE-FG02-09ER16026, provided all of the funding for this dissertation.

TABLE OF CONTENTS

List of Tables ...... vii List of Figures ...... ix Abstract ...... xiii

1. INTRODUCTION ...... 1

1.1 Importance of Understanding Actinide Ligand Bonding...... 1 1.2 Non-Aqueous Transuranic Chemistry ...... 1 1.2.1 Bonding in Actinides ...... 2 1.2.2 Challenges of Transuranic Non-aqueous Chemistry ...... 2 1.3 Transuranic Non-Aqueous Coordination Compounds ...... 4 1.3.1 Simple Non-Aqueous Coordination Complexes ...... 4 1.3.2 Air and Moisture Sensitive Non-Aqueous Transuranic Chemistry ...... 5 1.4 Thesis Objective ...... 7 1.5 Figures ...... 8

2. SYNTHESIS AND STRUCTURES OF TRIS TERPYRIDINE COMPOUNDS OF TRIVALENT LANTHAINDES AND AMERICIUM ...... 11

2.1 Introduction ...... 11 2.2 Results and Discussion ...... 11 2.3 Conclusion ...... 13 2.4 Experimental ...... 13 2.5 Figures...... 15

3. SYNTHESIS AND CHARACTERIZATION OF AMERICIUM AND CALIFORNIUM DITHIOCARBAMATES ...... 21

3.1 Introduction ...... 21 3.2 Results and Discussion ...... 21 3.3 Conclusion ...... 23 3.4 Experimental ...... 24 3.5 Figures...... 26

4. USING REDOX-ACTIVE LIGANDS TO UNDERSTAND BONDING IN TRIVALENT ACTINIDES ...... 31

4.1 Introduction ...... 31 4.2 Results and Discussion ...... 32 4.3 Conclusion ...... 35 4.4 Experimental ...... 35 4.5 Figures...... 37

5. UNDERSTANDING THE SCARCITY OF THORIUM PEROXIDE CLUSTERS ...... 44

5.1 Introduction ...... 44 5.2 Results and Discussion ...... 44 5.3 Conclusion ...... 46 5.4 Experimental ...... 47 5.5 Figures...... 47

6. UNCOVERING THE ORIGIN OF DIVERGENCE IN THE CSM(CRO4)2 (M = LA ‒ SM; AM) FAMILY THROUGH BAND STRUCTURE ANALYSIS AND AN EXAMINATION OF THE CHEMICAL BONDING IN A MOLECULAR CLUSTER ...... 49

6.1 Introduction ...... 49 6.2 Results and Discussion ...... 51 6.3 Conclusion ...... 57 6.4 Experimental ...... 58 6.5 Figures...... 61

7. CONCLUSION ...... 66

APPENDICES

A. TABLES FROM CHAPTER 2 ...... 68 B. TABLES FROM CHAPTER 3 ...... 71 C. TABLES FROM CHAPTER 4 ...... 75 D. TABLES FROM CHAPTER 5 ...... 90 E. TABLES FROM CHAPTER 6 ...... 92

References ...... 98

Biographical Sketch ...... 116

LIST OF TABLES

Table A.1. Crystallographic data of Ln(terpy)3I3 compounds ...... 68

Table A.2. Crystallographic data of Am(terpy)3I3 ...... 69

Table A.3. Selected bond lengths for Ln(terpy)3I3 ...... 70

Table A.4. Selected bond lengths for Am(terpy)3I3 ...... 70

Table B.1. Crystallographic table for An(DTC)3(phen) compounds...... 71

Table B.2. Selected bond lengths (Å) for An(DTC)3(phen) ...... 72

6 Table B.3. SF and SO splitting of the H15/2 ground multiplet derived from a CAS(11,8) wavefunction...... 73

2 Table B.4. QTAIM parameters derived from a CASSCF wavefunction. BCP(r) and  BCP(r) correspond to the electron density and laplacian of the electron density at the bond critical point, HBCP corresponds to the energy density point and BCP is the electron delocalization index. All values are in a.u...... 74

Table C.1. Crystallographic table of Ln/An DOPO complexes...... 75

Table C.2. Crystallographic table for AnDOPO complexes...... 76

Table C.3. Table of selected bond lengths for Ln/An DOPO complexes. (Å) ...... 77

Table C.4. Metrical oxidation states table of Ce(DOPOq)3...... 77

Table C.5. Metrical oxidation states table of Nd(DOPOq)3...... 78

Table C.6. Metrical oxidation states table of Gd(DOPOq)3...... 79

Table C.7. Metrical oxidation states table of Am(DOPOq)3...... 80

Table C.8. Metrical oxidation states table of Bk(DOPOq)3...... 81

Table C.9. Metrical oxidation states table of Cf(DOPOq)2(NO3)(py)...... 82

Table C.10. Crystallographic table of Np and Pu DOPO compounds...... 84

Table C.11. Selected bond lengths for Np and Pu DOPO compounds. (Å) ...... 85

vii

Table C.12. Metrical oxidation states table of Np(DOPOq)2(DOPOsq)...... 85

Table C.13. Metrical oxidation states table of Pu(DOPOq)3(DOPOsq)...... 86

Table C.14. Crystallographic information of AmBr3(thf)4...... 89

Table C.15. Selected bond lengths for AmBr3(thf)4. (Å) ...... 89

Table D.1. Crystallographic table of [Th(O2)(terpy)(NO3)2]3...... 90

Table D.2. Selected bond lengths for [Th(O2)(terpy)(NO3)2]3. (Å)...... 91

Table D.3. Peroxide bond lengths. (Å)...... 91

Table D.3. Selected bond angles for Th-Peroxide-Th. (o) ...... 91

Table E.1. Crystallographic information for CsM(CrO4)2...... 92

Table E.2. Crystallographic information for Cs2M2(CrO4)4 ...... 93

Table E.3. Selected bond distances (Å) for CsLn(CrO4)2 and CsAm(CrO4)2 ...... 94

Table E.4. Atomic orbital contributions to the 20 highest occupied  spin molecular orbitals. Minimum contribution 2%. Note that there are four further MOs in the next 20 with a small Am f contribution larger than 2%. There are no  spin MOs with Am 5f > 2%. The oxygen contributions are presented as Ox y, where x indexes the oxygen atom and y provides its p AO contribution to the MO...... 95

Table E.5. QTAIM Am–O BCP parameters (au) and delocalization indices for Am(CrO4)7Cs11 ...... 97

Table E.6. Parameters of the Am-5f reduced density matrix computed employing LDA+GA assuming U=6 and J=0.7, see Eq. 1. Largest probability weights w_i, corresponding quantum labels N_i (number of electrons) and J_i (total angular momentum)...... 97

viii

LIST OF FIGURES

Figure 1.1. Calculated Radial Extension Adapted from Crosswhite,H. M. et al. J Chem. Phys. 1980, 72, 5103. The calculated radial extension of the Xe core compared to Nd(III) (left). The calculated radial extension of the Rn core compared to U(III) (right)...... 8

Figure 1.2. Calculated orbital energies of 6d and 5f in the AnO2...... 8

2- Figure 1.3. The synthetic scheme for AnCl6 anions (top) The synthetic scheme for AnCl4(DME)2 adducts (bottom)...... 9

Figure 1.4. The representation of the dithiophosphinic acid (left) and the diselenophosphinate ligand (right)...... 9

Figure 1.5. The synthetic scheme of the trans bis imio Np(IV) compound ...... 9

Figure 1.6. The synthetic scheme of An(TRENTIPS) (An: Np, Pu)...... 10

Figure 2.1. The 9-coordinate Ln(terpy)3I3 structure...... 15

Figure 2.2. The 9 coordinate Ln(tepry)3I3 (left) and (right) geometric isomers ...... 15

Figure 2.3. UV-Vis-NIR spectrum of Ce(terpy)3I3...... 16

Figure 2.4. UV-Vis-NIR spectrum of Pr(terpy)3I3...... 16

Figure 2.5. UV-Vis-NIR spectrum of Nd(terpy)3I3...... 17

Figure 2.6. UV-Vis-NIR spectrum of Sm(terpy)3I3...... 17

Figure 2.7. UV-Vis-NIR spectrum of Eu(terpy)3I3...... 18

Figure 2.8. UV-Vis-NIR spectrum of Gd(terpy)3I3...... 18

Figure 2.9. The -Am center (left) and the -Am center (right)...... 19

Figure 2.10. Displays the packing of the iodides down the c axis in -Am (left) and -Am (right)...... 19

Figure 2.11. UV-vis-NIR spectrum of Am(terpy)3I3...... 20

Figure 3.1. Structure of Am(DTC)3(phen) (left) and Cf(DTC)3(phen) (right)...... 26

Figure 3.2. Absorption spectrum of Am(DTC)3(phen)...... 27 ix

Figure 3.3. Absorption spectrum of Cf(DTC)3(phen) ...... 27

Figure 3.4. Raman Spectrum of Cf(DTC)3(phen)...... 28

Figure 3.5. Absorption spectrum of Es(DTC)3(phen)...... 28

Figure 3.6. Emission spectrum of Es(DTC)3(phen) excited at 350 nm ...... 29

Figure 3.7. Lifetime measurements of the Es(DTC)3(phen) ...... 29

Figure 3.8. Molecular orbital scheme derived from a the CASSCF wavefunction...... 30

q Figure 4.1. Synthetic scheme of Ln/AnX3 with HDOPO ...... 37

q Figure 4.2. Solution UV-Vis spectrum of Ln(DOPO )3 compounds...... 38

q Figure 4.3. Magnetic susceptibility of Ce(DOPO )3 as a function of temperature. The measured q eff of the Ce(DOPO )3 at 300K is 2.49 B and at 2K it is 1.23 B...... 38

q Figure 4.4. Magnetic susceptibility of Nd(DOPO )3 as a function of temperature. The measured q eff of the Nd(DOPO )3 at 300K is 3.61 B and at 2K it is 1.97 B...... 39

q Figure 4.5. Magnetic susceptibility of Gd(DOPO )3 as a function of temperature. The measured q eff of the Gd(DOPO )3 at 300K is 7.90 B and at 2K it is 6.94 B...... 39

q Figure 4.6. 1H NMR spectrum of Ce(DOPO )3...... 40

q Figure 4.7. 1H NMR spectrum of Nd(DOPO )3...... 40

q Figure 4.8. 9-coordinate Tris An(DOPO )3 (An: Am, Bk) structure. The tert-butyls were omitted for clarity...... 41

q Figure 4.9. 9-coordinate Cf(DOPO )2(NO3)(py) structure. The tert-butyls were omitted for clarity...... 41

q Figure 4.10. Solid state UV-Vis-NIR spectrum of Am(DOPO )3...... 42

q Figure 4.11. Solid state UV-Vis-NIR spectrum of Bk(DOPO )3...... 42

q Figure 4.12. Solid state UV-Vis-NIR spectrum of Cf(DOPO )2(NO3)(py)...... 43

x cluster is capped by tridentate 2,2´,6´,2´´-terpyridine ligands. Hydrogen atoms on the terpy ligands have been omitted for clarity. Th = grey, O = red, N = blue, C= black...... 47

Figure 5.2. A depiction of the weak donor-acceptor interaction between Th(IV) and a π* orbital of peroxide in [Th(O2)(terpy)(NO3)2]3...... 48

Figure 6.1. The solid state UV-Vis-NIR absorption spectra of Cs2CrO4, CsNd(CrO4)2, and CsLa(CrO4)2 from 300 nm to 1000 nm...... 61

Figure 6.2. Polyhedral representations of CsLa(CrO4)2. (a) View along the c axis showing stacking of the lanthanum chromate layers with Cs+ cations in the interlayer space. (b) Depiction 2‒ of part of a single [La(CrO4)2]1‒ layer. La3+ is represented as blue polyhedra, CrO4 as orange tetrahedra, and Cs+ as tan spheres...... 61

Figure 6.3. a) Nine-coordinate environment of the La3+ cations in CsLa(CrO4)2 with an approximate muffin geometry. b) Coordination environment of Nd3+ and Sm3+ in CsLn(CrO4)2 2- (Ln: Nd,Sm), with O atoms shown as red spheres, but with CrO4 tetrahedra omitted for clarity. 2- All O atoms are donated from CrO4 moieties...... 62

Figure 6.4. Polyhedral representations of the structure of CsNd(CrO4)2. (a) A view along the b axis showing the interlayer channels. (b) Depiction of part of a [Nd(CrO4)2]1‒ layer. Nd3+ is 2- + represented as gold polyhedra, CrO4 as orange tetrahedra, and Cs as tan spheres...... 62

Figure 6.5. Polyhedral representations of  CsAm(CrO4)2. (a) View down the b axis showing the interlayer channels. (b) Single layer of one of the two-dimensional sheets. Am3+ is represented as 2- + dark red polyhedra, CrO4 as orange tetrahedra, and Cs as tan spheres...... 63

3+ 3+ Figure 6.6. Coordination environment of Am in CsAm(CrO4)2 with Am represented as dark 2- + red polyhedra, CrO4 as orange tetrahedra, and Cs as tan spheres. (a)  CsAm(CrO4)2. (b)  CsAm(CrO4)2...... 63

Figure 6.7. Solid-state UV-Vis-NIR absorption spectrum of  CsAm(CrO4)2 and  CsAm(CrO4)2 from 320 nm to 1200 nm. Inset: Absorbance vs. Optical Energy plot of  CsAm(CrO4)2 showing a band gap of ~ 1.65 eV...... 64

Figure 6.8. MO 266. Isovalue = 0.035. Dark red and green are the phases of the wavefunction. Grey spheres = Cr, red spheres = O, purple spheres = Cs. The Am atom is in the center of the image...... 64

Figure 6.9. MO 262. Isovalue = 0.035. Dark red and green are the phases of the wavefunction. Grey spheres = Cr, red spheres = O, purple spheres = Cs. The Am atom is in the center of the image...... 65

Figure 6.10. LDA+DMFT angle resolved photoemission spectra computed at T = 580 K. The corresponding 5/2 and 7/2 Am-5f spectral contributions are displayed in the right panel...... 65

Figure C.1. Schematic of the synthesis of Np and Pu DOPO...... 83

Figure C.2. Solid state UV-Vis-NIR of Np and Pu DOPO complexes compared to q Nd(DOPO )3...... 83

Figure C.3. 7-coordinate Am center of AmBr3(thf)4...... 88

Figure C.4. Solid state UV-Vis-NIR spectrum of AmBr3(thf)4...... 88

xii

ABSTRACT

As of 2014, there is an expected 69,000 metric tons of nuclear waste sitting in storage in the U.S. Little efforts have been made to deal with the radiotoxicity of the spent nuclear fuel (SNF). The problem arises from the complex mixture of the SNF and highly radioactive actinides. Due to the high radioactivity of the minor actinides (Pu-Cm), there is a lack of understanding the fundamental chemistry of the actinides. The focus of this work is to prepare coordination complexes that can be used as probes for elucidating changes in the structure and bonding across the actinides series Most coordination chemistry that has been studied with the actinide series has only utilized ligands stable to oxygen and moisture due to the difficulties of handling the transuranium actinides. The chemistry of non-aqueous ranium has made great progress, while, the non- aqueous chemistry of the transuranic elements is relatively unexplored and offers a wider platform for exploring methods of deducing electronic structure and information about the actinide-ligand bond. Such information can be very useful for discovering trends in the whole series. The beginning chapters focus on simple coordination compounds using soft N and S donor ligands for complexing Am-Cf. Since very little structure data is known for these elements and softer donor ligands have shown to have a preference over trivalent actinides than lanthanides, we focus on these systems to understand the trends in bonding across the 5f series. Chapter 4 focus on a series (U-Cf) of complexes using the redox active ligand 2,4,6,8- tetrakis(tert-butyl)-9-hydroxyphenoxanone (HDOPO) were synthesized in non-aqueous conditions under an inert atmosphere and have been fully characterized by X-ray, optical, magnetic, and computational techniques. Spectroscopic data reveals the An(DOPO)3 complexes of the earlier actinides being the tetravalent state, in contrast to the later actinides, they are in the trivalent state. Furthermore, the Cf(III) complex disrupts the tris-chelate trend due to radiolysis. It is also shown that the ligand undergoes redox transitions to stabilize the higher oxidation states of the earlier actinides. The results will help contribute toward gaining foundational knowledge of structure and bonding in non-aqueous transuranic chemistry as well as give insight into the participation of f-orbitals in bonding.

xiii

The ending chapters are out of the scope of non-aqueous chemistry but projects that pertain to the nature of the actinide series. As the first focuses on the effects of radiolysis. As we go to the heavier actinides, radiolysis affects the crystallization of our targeted products. In this case, an aged thorium source produces peroxide over time changing the result of the product. Lastly, is an example of driven degeneracy covalency in an americium chromate system. It was thought the later actinides tend to be more ionic, however we are finding small amount of covalent character partakes in the bonding. Collectively, this body of work primary focus is elucidating the structure and bonding of the f-elements through coordination complexes utilizing various techniques.

xiv

CHAPTER 1

INTRODUCTION

1.1 Importance of Understanding Actinide Ligand Bonding

The nuclear fuel cycle generates over third of the periodic table which results in a complex mixture of elements and radionuclides. Spent nuclear fuel is highly radioactive and needs to be stored safely for prevent migration of radioactive isotopes in the environment. Many of the radioisotopes that are produced are short lived and decay into stable elements by the time the fuel has cooled. However, the issue arises from the actinides series, Th-Cm, due to their long lived radioactive isotopes. Processes such as Transuranic Uranic Extraction (TRUEX)[1-4], Plutonium Uranium Recovery by EXtraction (PUREX),[1-3] and Selective ActiNide EXtraction (SANEX)[2,3] have been established to deal with the waste management problem to reduce the amount of high activity waste produce by separating out the stable/low activity fission products efficiently. However, these processes do not tackle the issue of the minor actinides separation, Am and Cm, from spent nuclear fuel. Once these elements are separated, they can be transmuted to elements with shorter half-lives or even stable elements. This provides a motive to research these elements to begin to understand the structure and bonding of these transuranic elements could allow the separation of these elements from the spent nuclear fuel to reduce the volume of waste. [5,6] This has been proven to be challenging due to their similar chemical and physical properties hence by probing the actinide ligand bond, ligand designed for separations of americium and curium can be undertaken.

1.2 Non-Aqueous Transuranic Chemistry Actinide chemistry has been dominated by aqueous conditions which limits the ligands available to use but also gives rise to structural and oxidation state speciation. With the possibility of stabilizing different oxidation state of metal, it can provide detailed electronic structure and bonding information in the actinide series that cannot be accomplished otherwise. The development of this field of chemistry provides support and insight on the periodic trends, bonding motifs, and electronic structures across the actinide series and against the lanthanide series to expand the knowledge of the behavior of the actinides in the nuclear fuel cycle.

1.2.1 Bonding in Actinides

As there are a variety of different bonds that occur across the periodic table, we are only focusing on the basic bonding motifs in the f block, ionic and covalent bonds. In the 4f series, the bonding is strictly ionic. The 4f orbitals are constructed and corelike underneath the Xe core, Figure 1.[7,8] These orbitals are not influenced by the external factors such as ligand field splitting, therefore perturbations of the orbitals do not occur, leading to the ionic character of the lanthanide series. In contrast to the 4f series, the actinides were thought to have the same chemistry. In the comparison of Nd(III) to U(III), the 5f orbitals extend past the Rn core allowing the 5f orbitals to participate in bonding. The early actinides have exhibited covalent character in the bonding whereas the mid-late actinides begin to follow the 4f trend. [1,7,9] As the f block is traverse, the 5f orbitals begin to contract. This contraction decreases the probability of orbital overlap. The question arises how does covalency exist in the mid to late actinides if there is a contraction of the 5f orbitals causing little to no orbital overlap.

The 5f orbitals of the mid to late actinides become degenerate with 2p orbitals which is represented in Figure 2.[7] The matching of the orbitals can lead to energy degeneracy driven covalency which has been documented since the 1960s and have been observed in actinide chemistry.[10-12] Typically, a covalent bond requires the frontier orbitals of the ligand and metal to mix, in addition to being energy degenerate.[1,7,13-15] For the earlier actinides, orbital overlap dominates whereas the later actinides energy degeneracy is predominating. This alludes to the actinides can have covalent character in the bonds without satisfying the criteria for a true covalent bond. On the other hand it is still unclear the functionally of the f orbitals later in the 5f series.

1.2.2 Challenges of Transuranic Non-Aqueous Chemistry

Non-aqueous coordination chemistry provides insight on actinide-ligand bonding by increasing the number and variety of ligands to elucidate the bonding occurring across the actinide series. In terms of separation, non-aqueous coordination compounds can provide detail of biphasic extractions by understanding the formation of actinide-ligand complex which can be used to refine this process. [16] Thorium and uranium chemistry have gained momentum and made great strides by showing these elements are capable of covalent bonds and a variety of

2 small molecule activation. [9,16] This is possible since these elements are weak  emitters can be handled safely at most laboratories. The same cannot be said for the transuranic elements. Since transuranic elements are high energy and emitters, strict regulations and facilities are required to work with these elements hindering research on these elements.

In addition to the regulations and specialized facilities to work with transuranic elements, there are many synthetic challenges to overcome as well. First, is the scarce availability of these elements. Since the transuranic elements are not accessible in bulk quantities, small scale manipulations have to be done. Small scales affect the crystallinity of the material and even the yield of the reactions. Before reactions are performed with transurancis, reactions are modeled using the early lanthanides due to their similar ionic radii. Unfortunately, lanthanides do not provide good analogues for majority of the actinides since the earlier actinides are redox active and the mid to late actinides are highly radioactive and radiolysis becomes prevalent. Radiolysis leads to degradation of the solvent and ligand over short periods such as hours to days. This causes the synthesis with the mid to late actinide challenging since the crystal formation must be quick to study the bonding and structure and if not, radiolytic products can form over this time, or even no product formation.

Secondly, non-aqueous coordination chemistry requires starting materials that are soluble in organic solvents and anhydrous. Majority of lanthanides, thorium, and uranium anhydrous starting materials derive form the metals. [17-19] However, transuranic metals are rare or even non- existing there for other routes need to be explored. Transuranic elements are usually in the form of oxide or halides. The oxides can be converted to inorganic salts by strong acids in water, but are still hydrated soluble in most organic solvents. Shown in Figure 3, Kozimor and coworkers 2- 2- have shown the anhydrous salts of AnCl6 are conveniently synthesized but the AnCl6 are thermodynamically stable causing coordination to ligands becoming challenging. [15,20,21] Gaunt and coworkers have made progress for neptunium and plutonium by synthesizing AnCl4(DME)2 compounds.[22] The AnCl4(DME)2 compounds are soluble in most organic solvents and are made with low cost reagents. Other starting materials have been reported for Np and Pu but these synthesizes require the metals and are very low yielding making these not ideal for pathways for starting material. [23-25]

1.3 Transuranic Non-Aqueous Coordination Compounds

Even though these challenges hinder the research of non-aqueous coordination compounds, it is still possible to perform this type of chemistry. The quintessential example of non-aqueous coordination compounds/organometallic complexes are the tris cyclopentadiene,

(MCp3), systems. This system exhibited unusual electronic behavior especially in the Cf(Cp)3 system where it was reported to be red in color with broad UV-Vis spectrum. [26] Kaltsoyannis used two computational methods to understand the bonding occurring in these systems. The first was using orbital mixing and spin densities which indicated that the metal-carbon bond was increasing as the series traverses. In contrast to QTAIM, the metal-carbon bond was becoming more ionic as the series progresses from left to right. [1] This leaves the questions; Is there covalency in the mid to late actinides and what effect does it have on the bonding and structure in the 5f series?

Systems such as, Borates and dipicolinic acid (HDPA), have been studied and well characterized from U to Cf, leading to the discovery of a break in bonding at berkelium. [27,28] In the borate system, each element exhibits a new topology that was not similar to an existing topology. Since the borate is very flexible and is versatile in bonding, the unique phenomena in the bonding and electronic structure could not be accounted to the borate lattice or the metal. [29,30] This research was further by moving to a molecular system, the An(HDPA)3, where each structure is isotypic to each other so the metal center could be directly probed.[ However, these systems provided detail on the behavior of the metals, the synthesis were performed in aqueous conditions. With the hope of moving towards non-aqueous conditions, insight in the bonding of these elements can be exploited.

1.3.1 Simple Non-Aqueous Coordination Complexes

Sulfur and nitrogen based ligands exhibit a higher selectivity for trivalent actinides over trivalent lanthanides. [31-36] This selectivity is not well understood but it is suggested due to to be a degree of covalent character in the mid to late actinide bond. Dithiophosphinic acids (HS2PR2) are major candidates for separation of the trivalent actinides from the trivalent lanthanides due 5 [37-39] H2S2P(o-CF3C6H4)2 has the largest Am/Eu separation factor of 10 . A further study was - done with a family of S2PR2 to understand the selectivity which is derived from the nature of

4 ligand’s  orbital mixing of the aryl groups in shown in Figure 4. As the aryl groups are more restricted the selectivity of the extractant increases. Macor et al. further this study using 2,2’- biphenylenedithiophosphinate and diphenyldithiphophinate ligands coordinating to Np and Pu to understand the effect of restricting of the ring rotation on the bonding with the actinides. [40] t Successfully Np[S2P( Bu2C12H6)]4, Np[S2P(C6H5)2]4, and Pu[S2P(C6H5)2]3(NC5H5)2 were synthesized and characterized. Neptunium was in the tetravalent state whereas the plutonium stayed in the trivalent state which was thought to be tetravalent and in the presence of other dithio based ligand the Pu(III) ion should be taken into consideration. Theoretical calculations showed that the constrain of the aryl rings affected the polarity of the sulfur leading to the selectivity of the extractants. Unfortunately, this study has not been examined past plutonium and no structural data exist for An-S (An= Am-Cf) bonding. Gaunt and coworkers extended the research of dichalcogenidophosphinic acids by moving to a softer donor, selenium analogs. [41] Since the selenium atoms are softer than the sulfur, the selenium orbitals would have more overlap with the actinide center. The Pu-Se bonds were shorter and more covalent that of the Ce- Se bond. It is still unclear where the covalency is deriving from but the little covalent character does affect the bonding in the transuranic.

3- Actinide hexachlorides, AnCl6 , were first targeted for anhydrous starting material, due to their octahedral geometries and the M-Cl bond is important to understand for speciation in spent nuclear, this system was a candidate for probing covalency in the actinides by using Ligand 3- K edge. AmCl6 was synthesized for comparison with the LnCl63- analogues to compare the 4f orbitals vs the 5f orbitals with the 3p orbitals of chlorine by using Cl K-edge.[22] It was found the Am-Cl bond had very little mixing of the 5f orbital with the 3p orbital compare to the Eu-Cl bond there was no mixing of orbitals. Even though the 5f-3p mix was not pronounced, the slightest covalent character can change the chemical reactivity and physical properties.

1.3.2 Air and Moisture Sensitive Non-Aqueous Transuranic Chemistry

Although U-Am have access to higher oxidation states past the trivalent oxidation state 2+ and have potential to have multiple bonds (AnO2 ), headway has only been made in uranium chemistry. Recently, multiple bond uranium chemistry has been a hot topic and led to a greater understanding of uranium electronic structure. [11,42,43] Since the transuranic have access to their

5 higher oxidation states, multiple bond chemistry can further our knowledge in the 5f/6d participation in bond in addition to understanding how covalency and multiple bond chemistry change across the series. In attempts to synthesize Np and Pu imidos, Brown et al. were successful synthesizing a trans-bis imido Neptunium compound, Np(NDIPP)2(tBu2bipy)2Cl represented in Figure 5.[44] The reactivity between U(IV) and Np(IV) differ from each other under the same conditions. The Np bisimido was isolated under the same conditions as U mono imido compound. This shows that similar actinides are not good surrogates for modeling other actinides of the same and each actinide needs to be explored independently. Theoretical calculations show that Np(IV) 5f/6d orbitals have significant covalent overlap with the 2p orbitals of the imido. Even though U(V) imido analogue also have significant metal overlap, the Np imido has more overlap and is contributed to the 5f orbitals being more degenerate with the 2p nitrogen orbitals. Attempts were made to further the imido study later in the series however it was not successful.

Further attempts of studying multiple bond chemistry in transuranics were done by Brown and coworkers. They utilized a triamidoamine (TREN) framework (Figure 6) to direct the chemistry on Np and Pu center. [45] Even though, multiple bond chemistry was not achieved, it was possible to replace the chlorine atom with a softer, iodine and even reduce the metal center from IV to III. This system provided reactivity properties of these metals that have not been observed in the transuranics and is a platform to further reactivity studies with these elements.

Recently, transuranic organometallic chemistry has been explored with the elements of Np and Pu. These studies lead to low valent Np(III) and Pu(II) complexes which these oxidations are extremely hard to achieve and are only possible under non-aqueous anhydrous conditions or harsh conditions. [46-48] These compounds provided structural, spectroscopic, electronic structure, and redox properties that continues to develop our understanding the chemistry of the minor actinides.

Unfortunately, there is a lack of non-aqueous chemistry for transplutonium elements. As this field of chemistry has expanded the knowledge of the structure, bonding, and redox properties of the earlier actinides, it provides motivation to advance this chemistry to the later actinides to further our knowledge of these elements by probing structural and redox trends.

1.4 Thesis Objective

This body of work focuses on non-aqueous chemistry of the transuranium elements extending to einsteinium by using different donor ligands to probe the contribution of the f orbitals in the actinide-ligand bonds. The focus begins on simple ligand systems that are used for separations such as, dithiocarbamates, terpyridines, and bipyridines, to understand the bonding occurring in non-aqueous coordination chemistry in the mid to late actinides. These soft donors are used as building blocks for larger ligands for separations. The simplicity of contributing moieties is of focus to gain structural data on actinide-ligand bonds.

Advancing this work by utilizing a redox active ligand to synthesize isostructural compounds across the 5f series under inert and anhydrous environments to further exploit unusual characteristics of the mid to late actinides. The comprehensive study under these conditions has not been reported in literature and is critical to develop to begin to understand the bonding of the transplutonium 5f orbitals participation. With this study, the electronic structure o

Lastly, the focus turns to anhydrous starting material of Am to begin to use in non- aqueous coordination chemistry and organometallic chemistry. This chemistry has not extended past plutonium due to the lack of starting materials and manipulation of the heavier actinides. Despite of what we know of transition metals, lanthanides, and early actinides the chemistry of the late actinides are different and good starting materials are unknown. Without having synthetic pathway for starting materials, non-aqueous and organometallic chemistry of the mid to late actinides will be extremely difficult and slow moving.

1.5 Figures

Figure 1.2 Calculated orbital energies of 6d and 5f in the AnO2.

2- Figure 1.3 The synthetic scheme for AnCl6 anions (top) The synthetic scheme for AnCl4(DME)2 adducts (bottom).

Figure 1.4 The representation of the dithiophosphinic acid (left) and the diselenophosphinate ligand (right).

Figure 1.5. The synthetic scheme of the trans bis imio Np(IV) compound.

Figure 1.6. The synthetic scheme of An(TRENTIPS) (An: Np, Pu).

CHAPTER 2 SYNTHESIS AND STRUCTURES OF TRIS TERPYRIDINE COMPOUNDS OF TRIVALENT LANTHANIDES AND AMERICIUM

2.1 Introduction Selective separation of the trivalent actinides from the lanthanides is a key issue in waste reprocessing and management. Efforts have been put forth to design extractants for the trivalent actinides by using softer donors such as N and S based ligands. These ligands have shown to be more selective for the trivalent actinides, however the selectivity is still not well understood. N- heterocycle ligands, bis trazinyl pyridine (BTP) and bis triazyinyl bipyridine (BTBP), have been gaining interest for separation of the trivalent actinides from the trivalent lanthanides due to their high selectivity of Am(III) over Eu(III)[1,7,23-25]. These systems have only been studied in the solution phase.

Utilizing 2,2’-6’,2”- terpyridine (terpy) as a chelator for americium to synthesize a homoleptic N-donor compounds that the structure and bonding of solid state of Am-N bond. Only a few crystals of Am are published in CSD, however most of these are oxygen containing ligands. Here in, we report a comparative study of the Ln(III) terpy complexes to Am(III) terpy compound in non-aqueous conditions

2.2 Results and Discussion

The synthesis of LnI3 and terpy in acetonitrile resulted in Ln(terpy)3I3. Crystallographic data revealed Ln(terpy)3I3 complexes crystallized in the rhombohedral chiral space group R3. Three terpy molecules chelate the metal center generating a 9-coordinate distorted tricapped trigonal prism geometry depicted in Figure 2.1. The distortion arises from the flexibility of the terpy molecules causing the molecule to have C3 symmetry. Three iodides counter balance the the Ln(terpy) moiety in the outer coordination sphere. The comparison of Ln-N bond shown in Table 2.1, reveals a steady decrease across the series due to the decreasing size of the metal ions.

In the unit cell only one of the enantiomers is present. In Figure 2.2, shows the  and  isomers that appear in the Ln(terpy)3 crystal structures. This is unique since terpyrine is an achiral molecule and has versatility in its bonding, spontaneous resolution of geometric isomers

would not be suspected. Ephritikhine and coworkers reported synthesis and structure of La-Nd tris terpy compounds. [48] These crystallized in the centrosymmetric orthorhombic space group

Pcca. The Ln(terpy) moiety has D2h symmetry with a mirror plane done the bond of the metal center and one of the nitrogens. In the case of the rhombohedral complexes, the packing of the iodides influence the distortion the terpyridine molecules to increase the symmetry of the compound.

The UV-Vis-NIR results of the Ln(terpy) complexes show a broad charge transfer peak around 430 nm (Figures 2.3-2.8). Typically, terpyridine exhibits a * transition at 350 nm. The charge transfer band arises from a – anion interaction. [49] The iodide must be close enough to a terpyridine molecule to have interaction. This elucidates the distortion of the terpyrindie rings around the metal center causing an increase in symmetry. In addition, no f-f transition peaks are visible for any of the f elements. This is due to the f-f transitions being forbidden and the pi-anion interaction be allowed and intense.

The synthesis of Am(terpy)3I3 led to two different polymorphs  and  Am(terpy)3I3. The dominant product ( crystallized in the rhombohedral chiral space group R3 where the minor product ( crystallized in the centrosymmetric orthorhombic space group Pcca. Each Am center is coordinated by three terpyridine molecules via the nitrogens exhibiting the 9-coordinate tricapped trigonal prism. Figure 2.9, shows the two-different coordination environments of the Am center in each polymorph, and the respective isomers each structure.The Am-N bonds range from 2.63(2) – 2.64(3) Å for the -Am and 2.570(5) – 2.657(5)Å for the -Am. The bonds are within reason of each other, therefore the difference in geometry must rise from packing of the crystal.

Further analyzing the environment of the Am centers, the -Am center of the display a

C3 symmetry whereas the -Am center displays a mirror plane down the Am-N5 bond serving us

D2h realness. The packing of the structures are shown in Figure 2.10. The -Am has a layer of iodides separating the Am(terpy) moieties from each other. In comparison to the -Am, the iodides are intercalated between the pockets of the Am(terpy) moieties which do not crowd the terpyridine molecules.

The UV-Vis-NIR spectrum of Am(terpy)3I3 displayed in Figure 2.11, shows the broad charge transfer band from the –anion interaction from the iodide to the terpyridine molecule. The spectrum also reveals the f-f transitions of Am(III) at 510nm and 830 nm. The question arises, why are the Am f-f transition visible whereas all the other lanthanides f-f transitions were not.

2.3 Conclusion

In summary, the synthesis was of Am(terpy)3I3 was successful. Due to the versatility of terpyridine coordinating to the metal, allowed for different polymorphs to form. As much structural data does extend past plutonium, this system give rise to possible bonding of Am to N- donor ligands which directly relates back to separations of the minor actinides.

2.4 Experimental Caution! 243Am and 249Cf are a high energy  emitter that potentially have serious health risks. All studies with these actinides were conducted in a laboratory equipped to study transuranium elements. HEPA-filtered hoods and gloveboxes with a series of instrument continually monitor the radiation levels in the laboratory. All free-following actinide solids are handled in gloveboxes, and the products are only examined when coated with immersion oil. There are significant limitations in accurately determining yields of these actinide compounds because it requires drying, isolation and weighing a solid, which possess an inhalation hazard and manipulation difficulties give the small quantities of product from these reactions. Anhydrous Acetonitrile, 2,2’-6’,2”- Terpyridine, Lanthanide oxides (Ce-Gd) and concentrated hydroiodic was purchases from Sigma-Aldrich without further purification

Crystallographic Studies. Single crystals of each compound were mounted on a Mitogen mounts with krytox oil and the crystals were optically aligned on a Bruker D8 Quest X-ray Diffractometer using a built in camera. Preliminary measurements were performed using an Imus X-ray source (Mo Ka, l= 0.71073 Å) with high-brillance and high-performance focusing quest multilayer optics. APEXIII software was used for solving the unit cells and data collection. The reflection’s intensities of a sphere were collected by a mixture of four sets of frames. Each set had a different omega angle for the crystal, and each exposure covered a range of 0.50 in , totaling to 1464 frames. The frames were collected with an exposure time of 5-25 second which 13

was dependent on the crystal. SAINT software was used for data integraphic including polarization and Lorentz corrections. PLATON was used to finalize the structure for any issues. CIFs are available from the Cambridge Crystallographic Data Centre (CCDC) and are given in the Supporting Information

UV-Vis-Near-IR (NIR) Spectroscopy. UV-vis- NIR data were collected for each compound using a Craic Technologies microspectrophotometer. Single crystals of each compound were paced on a quartz slide in immersion oil, and the data was collected from 300 nm to 1100 nm.

General synthesis of Ln(terpy)3I3: A 20 mL scintillation vial was equipped with 10 mg of Ln2O3 and hit with 3 x 300ml of HI until dryness. The lanthanide residue was dissolved in 0.5 mL of acetonitrile. A 0.5 mL solution of terpyrindie in acetonitrile was added to the reaction vial. The solution turned orange. Upon standing, yellow prismatic crystals formed which were suitable for X-ray diffraction.

243 Synthesis of Am(Terpy)3I3. In a 20 mL vial, AmO2 was dissolved in 300 l of HI. The acid was boiled off and this cycle was repeated two more times. The AmI3 residue was dissolved in 0.5 mL of acetonitrile. A solution of terpyridine in acetonitrile was added to the reaction vial. Upon standing, yellow prism crystals formed which were suitable crystals for X-ray diffraction studies.

249 Synthesis of Cf(Terpy)3I3. In a 20 mL vial, CfCl3 was dissolved in 300 l of HI. The acid was boiled off and this cycle was repeated two more times. The CfI3 residue was dissolved in 0.5 mL of acetonitrile. A solution of terpyridine in acetonitrile was added to the reaction vial. Upon standing, yellow prism crystals formed which were suitable crystals for X-ray diffraction studies.

2.5 Figures

Figure 2.1. The 9-coordinate Ln(terpy)3I3 structure.

Figure 2.2. The 9 coordinate Ln(tepry)3I3 (left) and (right) geometric isomers.

1.8 1.6 1.4 1.2 1 0.8 0.6

Absorbance Absorbance (a.u) 0.4 0.2 0 300 400 500 600 700 800 900 1000 1100 Wavelength (nm)

Figure 2.3. UV-Vis-NIR spectrum of Ce(terpy)3I3.

1.6

1.4

1.2

0.8

0.6

Absorbance Absorbance (a.u.) 0.4

0.2

0 320 420 520 620 720 820 920 1020 Wavelength (nm)

Figure 2.4. UV-Vis-NIR spectrum of Pr(terpy)3I3.

1.2

0.8

0.6

0.4 Absorbance Absorbance (a.u.) 0.2

0 300 400 500 600 700 800 900 1000 1100 Wavelength (nm)

Figure 2.5. UV-Vis-NIR spectrum of Nd(terpy)3I3.

1.6 1.4 1.2 1 0.8 0.6

0.4 Absorbance Absorbance (a.u.) 0.2 0 320 420 520 620 720 820 920 1020

Wavelength (nm)

Figure 2.6. UV-Vis-NIR spectrum of Sm(terpy)3I3.

1.8 1.6 1.4 1.2 1 0.8 0.6

Absorbance Absorbance (a.u) 0.4 0.2 0 300 500 700 900 1100 Wavelength (nm)

Figure 2.7. UV-Vis-NIR spectrum of Eu(terpy)3I3.

1.8 1.6 1.4 1.2 1 0.8 0.6

Absorbance (a.u.) Absorbance 0.4 0.2 0 300 500 700 900 1100

Wavelength (nm)

Figure 2.8. UV-Vis-NIR spectrum of Gd(terpy)3I3.

Figure 2.9. The -Am center (left) and the -Am center (right).

Figure 2.10. Displays the packing of the iodides down the c axis in -Am (left) and -Am (right).

1 0.9 0.8 0.7 0.6 0.5 0.4

0.3 Absorbance Absorbance (a.u.) 0.2 0.1 0 300 400 500 600 700 800 900 1000 1100 Wavelength (nm)

Figure 2.11. UV-vis-NIR spectrum of Am(terpy)3I3.

CHAPTER 3 SYNTHESIS AND CHARACTERIZATION OF AMERICIUM AND CALIFORNIUM DITHIOCARBAMATES

3.1 Introduction An extensive study of actinide coordination chemistry is of importance for solving the waste issue in the nuclear fuel cycle. The primary issue arises from the transuranics leading to radiotoxicity of the waste and leading to long term potential hazards such as environmental mobility and speciation. To deal with the radiotoxicity, the separation of the transuranic elements must be well understood, especially Am and Cm. Softer ligands containing nitrogen and sulfur have proven to be effective for separations, however the selectivity is ambiguous. The organodithiophosphinate family has displayed the largest separation factors of AnIII/LnIII.[23-25] The selectivity of the trivalent actinides over the lanthanides is linked to covalent character in the actinide-ligand bond.

The lack of structural data on these elements hinders the progress towards understanding the behavior and bonding of these elements. Only a hand full of coordination compounds of transuranic contain Am-Cf, majority of these are oxygen containing which the bonding is believed to be ionic. By focusing on softer donor ligands with the trivalent actinides in the solid state can add to ever growing evidence of covalency in the mid to late actinides by supplying structural data.

Here in, we focus on the coordination of dithiocarbamates (DTC) to Am and Cf. These ligands contain a dithio group like those in the organodithiophshinate family. The DTCs have been well documented with the lanthanide series by the Stoll group. With the addition of 1,10- phenanthroline (phen) acting as a synergist ligand, An(DTC)3(phen) (An: Am, Cf) were successfully synthesized and characterized.

3.2 Results and Discussion

The reaction of Am(NO3)3, DTC, and phen resulted in Am(DTC)3(phen). The Am(III) center adopts an 8-coordinate geometry known as distorted square antiprism. Three DTC ligand coordinate the Am in a -2 fashion. The Am-S bond length ranges from 2.8015(8) – 2.9304(8) Å 21 with a bond length of 2.875(8) Å. It is difficult to tell which sulfur is anionic and dative due to the lack of Am-S information in the CCDC. The phen ligand chelates the Am center bidentately with an average Am-N bond length of 2.604 (2) Å. In comparison to the Am(HDPA)3 and

[50] [Am(PDA)(NO3)(H2O)2]·H2O the Am-N bonds 2.531 (4) -2.591 Å and 2.589 (11)Å, the Am-N from the bipy is longer. The elongation of Am-N in this system is due to the lack of the carboxylic acid complexing the metal center forcing a shorter Am-N bond. The UV-Vis spectrum shown in figure X, is typical for a Am3+ compound with a -* transition from the dithiocarbamate ligand at 350 nm. The peaks that appear at longer wavelengths are the f-f transitions and are broader than typical.

The reaction of Cf(NO3)3, DTC, and phen resulted in a molecular structure of

Cf(DTC)3(phen)•MeCN. The Cf(III) center adopts an 8-coordinate geometry known as dodecahedron. Three DTC ligand coordinate the Cf center in a -2 fashion. The Cf-S bond ranges from 2.795-2.9066 Å with an average bond length of 2.836(2)Å. No structural data has been reported in literature form Cf-S bond. The phen ligand chelates the Cf through the nitrogen bidentately with an average Cf-N bond length of 2.556 (6) Å. In comparison to the nitrogen in the Cf(HDPA) system, with the average bond distance of 2.522 (4) Å, the bipy bond is longer. Like the Am-N bond, the oxygens pull in the metal closer causing shorter distance for the Cf-N bond. However, Cf-N bond was expected to decrease about 0.03 Å since the contraction of the ionic radii decrease by this amount. The total difference is 0.06 Å decrease, double from what we expected which this phenomenon has been report in other systems containing californium. The UV-Vis spectrum reveals a -* transition at 350 nm and at the longer wavelengths shows broad f-f transitions which are not typical for f-elements. Raman spectroscopy in figure 3.4 showed the disappearing of the dithiocarbamate stretches and a peak at 1000 nm which is assumed to be from the Cf-S stretch.

The reaction of Es(NO3)3, DTC and phen resulted in a red single crystal. Xray studies could not be performed due to the radiolysis damage to the crystal. The crystals stayed intact long enough to get preliminary absorption and photoluminescence spectroscopy. Figure 3.5 shows the absorption spectrum of Es(DTC)3(phen). The peak at 350 arises from the -* transition. The origin of the broad peak at 520 nm is thought to be from the Es. Due to the lack of

22 experimental data of Es, computational studies are being performed to further our understanding. The Es complex was excited with a wavelength set at 350 nm to excite the phenanthroline ligand to excite the metal center. The excitation spectrum is shown in Figure 3.6. Life time measurements of the emission were measured revealed the transition states last about 4- 10 ms.

Lifetime measurements were not done on Cf(DTC)3(phen), therefore we cannot make a comparison to lifetime results of the Es(DTC)3(phen).

The electronic structure was calculated using the CASSCF approach to take into the static correlation effect into the system which can be seen in the first column of Table 3.3. The correction to the energy of the spin-free (SF) states due to dynamic correlation effects are included in the second column of Table 3.3. The last two columns include the spin-orbit (SO) coupling with and without dynamical effects. At a first glance, the dynamical correlation is not strong enough to alter more than ca. 100 cm-1 the energy of the state. Due to the nature of the compound is a Kramers system the degeneracy is perfectly observed in the SO states. From the molecular orbital perspective, it can be seen that the 5f orbitals are close in energy to the bonding orbitals of the ligand which allow to have some degree of driven-degeneracy covalency (Figure 3.8).

The bonding properties of the Cf3+ in the complex were assessed by topological analysis of the electron density according to the Bader’s theory. The electron density at the bond critical point, BCP(r), for Cf-N bonds is very similar to the Cf-S bonds with some of the latter slightly decreased electron density (Table 3.4). However, it is surprising the difference in the energy density (HBCP) which is more negative in the case of Cf-S bonds than Cf-N. Comparison of these [56] vales with those reported by Kerridge et al. for some HBCP values for Ln-N bonds (BTP ligand) and Ln-O (H2O ligand), it is possible to say that Cf-N bond are less covalent than those lanthanide BTP compounds. This could be explained by the unexpected covalent degree exhibited by the Cf- S which can reduce the strength of the Cf-N bond.

3.3 Conclusion

23 bond was observed in the An-S bond. The An-S bond did have a slight degree of covalency which elongated the An-N bond. Preliminary results of Es(DTC)3(phen) were collected but due to radiolysis no further characterization could be performed.

3.4 Experimental

243 249 253/254 Am(t1/2=7380 years), Cf(t1/2=351 years), and Es (t1/2=20.5/275.7 days) represent serious health risks due to their a emission as the radiotoxicity associated with their , , and  emitting daughters. All studies with these actinides were conducted in a laboratory dedicated to studies on transuranium elements. This laboratory is in a nuclear science facility and is equipped with HEPA-filtered hoods and gloveboxes. A series of instruments continually monitor the radiation levels in the laboratory. All free-following actinide solids are handled in gloveboxes, and the products are only examined when coated with immersion or krytox oil. There are significant limitations in accurately determining yields of these actinide compounds because it requires to drying, isolating, and weighing a solid, which possess an inhalation hazard and manipulation difficulties given the small quantities of product from these reactions. 1,10- phenanthroline, diethyldithiocarbamic acid diethylammonium salt and anhydrous acetonitrile was purchased from Sigma-Aldrich without further purification.

Crystallographic Studies. Single crystals of each compound were mounted on a Mitogen mounts with krytox oil and the crystals were optically aligned on a Bruker D8 Quest X-ray Diffractometer using a built-in camera. Preliminary measurements were performed using an Ims X-ray source (Mo Ka, = 0.71073 A) with high-brillance and high-performance focusing quest multilayer optics. APEXIII software was used for solving the unit cells and data collection. The reflection’s intensities of a sphere were collected by a mixture of four sets of frames. Each set had a different omega angle for the crystal, and each exposure covered a range of 0.50 in , totaling to 1464 frames. The frames were collected with an exposure time of 5-25 second which was dependent on the crystal. SAINT software was used for data integraphic including polarization and Lorentz corrections. PLATON was used to finalize the structure for any issues. CIFs are available from the Cambridge Crystallographic Data Centre (CCDC) and are given in the Supporting Information.

Computational details A correct theoretical description of the ground and excited states of molecules containing heavy-elements, is a challenging task because of the states are strong dependent of different parameters. First, the scalar relativistic effects and spin-orbit coupling interaction are of fundamental importance to describe the electronic structure and spectroscopic properties in these kind of molecules and second, a lot of low-lying states derived from a 5fn configuration produce a wave function with strong multiconfigurational character. Complete Active Space Self-Consistent Field (CASSCF) approach and its varieties,[51,52] which allows one (i) to construct all possible configurations within a chosen active orbital space and, optionally, a partitioning of the active space with limitations placed on the excitation levels and (ii) to include spin−orbit (SO) coupling via “state interaction” or from the onset, have shown to be an effective methodological tool in the description of actinide compounds. The CAS approach provides a reliable treatment of multiconfigurational character present in open-shell actinide systems, and it can be used with all-electron relativistic Hamiltonians. The two-step methodology that we used to obtain accurate wavefunctions involve (i) eigenvalues and eigenvectors obtained from a CASSCF calculation, with energies eventually corrected by a second-order multireference perturbation method (NEVPT2)[53] and (ii) SOC effects included by quasi-degenerate perturbation theory (QDPT), where the multiplets stemming from the S = Ms CASSCF states are mixed by the spin−orbit mean field (SOMF) operator. All calculations were carried out using the ORCA program developed by the Neese’s group.[54]

In all the calculations the scalar relativistic recontracted SARC-TZVP basis set was employed.[55] This basis set accurately represent HF reference wave functions and provides a good description of CASSCF excitation energies and the effect of the SOC operator when compared to basis set limit. All calculations incorporated, also, the scalar relativistic Douglas−Kroll−Hess Hamiltonian at second order (DKH2). Regarding to the starting CAS-wavefunction, the active space considered was composed by one p-orbital including DTC ligands involved in sigma bonding plus the seven 5f orbitals of Cf. Thus, the active space corresponds to a CAS(11,8) (eleven electrons in eight orbitals). This active space is not the optimal and these results are only preliminary results due to other calculations are running currently with a larger active space. These type of systems are usually difficult to treat with large active spaces due to the numbers of atoms involved.

UV-Vis-Near-IR (NIR) Spectroscopy. UV-Vis- NIR data were collected for each compound using a Craic Technologies microspectrophotometer. Single crystals of each compound were paced on a quartz slide in immersion oil, and the data was collected from 300 nm to 1100 nm.

243 Synthesis of Am(DTC)3(phen): A 20 ml scintillation vial was charged Am(NO3)3 (5.0 mg, 0.011 mmol ) and 500 l of acetonitrile. A solution of DTC (7.6mg, 0.033 mmol) and phen (2.1 mg, 0.011 mmol) in 500 l of anhydrous acetonitrile was added to the vial. The solution turned bright yellow. Upon standing, yellow rod crystals formed which were suitable for X-ray analysis.

249 Synthesis of Cf(DTC)3(phen): A 20 ml scintillation vial was charged Cf(NO3)3 (5.0 mg, 0.012 mmol ) and 500 l of acetonitrile. A solution of DTC (7.7 mg, 0.040 mmol) and phen (2.1 mg, 0.012 mmol) in 500 l of anhydrous acetonitrile was added to the vial. The solution turned bright green. Upon standing, green rod crystals formed which were suitable for X-ray analysis.

Synthesis of Es(DTC)3(phen): In a 5 ml conical vial, 0.4 g of EsCl3 was dissolved in 10 l of 6M nitric acid. The solution was evaporated to dryness. The residue was dissolved in 5 l of acetonitrile. An additon of 5 ml of a stock solution containing DTC ( mg, mmol) and phen( mg, mmol) was added to the Es solution. A red single crystal was formed.

3.5 Figures

Figure 3.1. Structure of Am(DTC)3(phen) (left) and Cf(DTC)3(phen) (right).

2 1.8 1.6 1.4 1.2 1 0.8 0.6 0.4

Absorbance Absorbance (a.u.) 0.2 0 320 420 520 620 720 820 920 Wavelength (nm)

Figure 3.2. Absorption spectrum of Am(DTC)3(phen).

1.4

1.2

0.8

0.6

0.4

0.2 Absorbance u.) Absorbance (a. 0 350 450 550 650 750 850 950 1050 Wavelength (nm)

Figure 3.3. Absorption spectrum of Cf(DTC)3(phen).

35000

30000 Cf(DTC)3(phen) 25000 phen

20000 DTC

15000

10000 Counts (a.u.) Counts

5000

0 100 600 1100 1600 2100 2600 3100

Wavelength (nm)

Figure 3.4. Raman Spectrum of Cf(DTC)3(phen).

1 0.9 0.8 0.7 0.6 0.5 0.4

Absorbance (a.u.) 0.3 0.2 0.1 0 320 420 520 620 720 820 920 wavelength (nm)

Figure 3.5. Absorption spectrum of Es(DTC)3(phen).

2.50E+05

2.00E+05

1.50E+05

1.00E+05 arb. arb. Units

5.00E+04

0.00E+00 400 500 600 700 800 900 Wavelength (nm)

Figure 3.6. Emission spectrum of Es(DTC)3(phen) excited at 350 nm.

6.00E+03

5.00E+03

4.00E+03

3.00E+03

2.00E+03

1.00E+03

0.00E+00 15000 20000 25000 30000 35000 40000 45000 50000

Figure 3.7. Lifetime measurements of the Es(DTC)3(phen)

Figure 3.8. Molecular orbital scheme derived from a the CASSCF wavefunction.

CHAPTER 4 USING REDOX-ACTIVE LIGANDS TO UNDERSTAND BONDING IN TRIVALENT ACTINIDES

4.1 Introduction

Trends for these properties have been well established for d-block elements, and many studies have repeatedly highlighted contrasting chemistry between early and late transition metals. The relatively fewer studies on actinides suggest that elements early in the series take on covalent character, due to mixing of the 6p, 6d, and 5f orbitals for bonding to organic ligands.[1,7] As the actinide series is traversed, the later elements begin to behave like lanthanides, where the 3+ oxidation state and ionic bond character dominates. Elements past plutonium are known to have similar chemical and physical properties to lanthanides, causing separation of minor actinides and lanthanides in spent nuclear fuel to be challenging. While actinides are typically associated with higher degrees of covalency in their metal-ligand bonds as compared to the lanthanides, leveraging this property for separations of trivalent ions is challenging since the degree of covalency is known to decrease with the lowering of the oxidation state for actinides.

Recent work in the actinide series using tris(dipicolinic acid) derivatives, M(HDPA)3 (M = Am, Cm, Cf, Bk), have demonstrated that while the above trend is generally true for transuranic elements, the availability of the +2 oxidation state for californium causes a deviation in this trend, which overrides the minor contraction of the f orbitals that is typically observed. [28,58] We hypothesized that this trend could be further perturbed using redox-active ligands, those that accept electron density into their pi* orbitals. Such a class of ligands has been shown to produce highly covalent transition metal derivatives, and thus offers an opportunity to study covalency in metal-ligand bonds for transuranic elements. The dioxophenoxazine (DOPO) ligand (DOPO = 2,4,6,8-tetra-tert-butyl-1-oxo-1H-phenoxazin-9-olate) is an appropriate choice, given its use on d-[59,60] and f-block [61-63]metals. Here we present a new family of trivalent lanthanide (Ce, Nd, Gd) and actinide (Am, Bk, Cf) tris(DOPO) derivatives, along with their full characterization using structural, spectroscopic, and computational techniques. Our findings highlight differences in bonding and covalency between the different regions of the f-block.

4.2 Results and Discussion: Initial synthetic efforts focused on the synthesis of homoleptic, redox-active ligand complexes that would serve as model compounds for transuranic elements and create a baseline for bonding properties across the actinides. Taking advantage of the high oxophilicity of the f- block elements, complexes incorporating DOPO (DOPOq =2,4,6,8-tetra-tert-butyl-1-oxo-1H- phenoxazin-9-olate) ligands were targeted.[60,61] Tris-ligand complexes of similar ONO-chelating ligands (ONO = 3,5-di-tert-butyl-1,2-quinone-1-(2-oxy-3,5-di-tert-butylphenyl)imine) have been characterized for strontium and samarium, while bis-ligand complexes for both DOPO and ONO are reported for many other metals.[59,60] We postulated that the large ionic radii of the f-block metals would permit formation of tris-DOPO complexes, and the redox-activity of the ligands would allow for the isolation an isostructural set across the actinides, regardless of the metal oxidation state. An efficient synthesis using higher boiling solvents that would quickly and reliably yield the desired tris(ligand) complexes was required for eventual extension to the appropriate transuranic materials. Treating stirring pyridine solutions of either CeCl3, NdCl3, or GdCl3 with three equivalents of HDOPOq generated deep blue solutions in each case, indicative of ligand metallation. Reaction schematic is shown in Figure 4.1. Removal of the volatiles in vacuo followed by trituration with pentane and filtration to remove pyridinium chloride produced the q corresponding tris(ligand) products, M(DOPO )3 (M = Ce, Nd, Gd) as blue solids in good yields 1 (76%, 68% and 71% respectively). Analysis by H NMR spectroscopy of Gd(DOPO)3 wasn’t possible due to the paramagnetism stemming from the 7 unpaired electrons of Gd(III), but the Ce(III) and Nd(III) centers produced interpretable data shown in Figure 4.2 and 4.3 respectively. With a synthetic procedure and full characterization established for these molecules, their syntheses were scaled to perform on 5 milligram quantities of halide salts in preparation for q repeating these procedures with transuranic elements. Crystallization of Ce(DOPO )3, q q Nd(DOPO )3 and Gd(DOPO )3 was possible directly from small scale mixtures utilizing 10 mg of MCl3, 3 equiv ligand, and 5 mL of pyridine. Slow evaporation over 24 hours caused blue crystals to reliably and reproducibly precipitate from these concentrated solutions. Analysis of q q the crystals by X-ray crystallography confirmed the identities as Ce(DOPO )3, Nd(DOPO )3 and q [62,63] Gd(DOPO )3. In each case, three statistically indistinguishable DOPO ligands were 32 observed. Because structural parameters are useful in assigning ligand oxidation states, analysis of the intraligand metrical paramaters for each molecular structure were studied using the Metrical Oxidation State (MOS) method previously established by Brown.[60] In each case, the ligands were determined to be monoanionic, confirming the +3 oxidation state. q To further support the ground state electronic structures in Ln(DOPO )3 (Ln = Ce, Nd, and Gd), variable temperature magnetization and field-dependent magnetic measurements were q q performed (Figure 4.4-4.7). At room temperature, the μeff values of Ce(DOPO )3, Nd(DOPO )3, q and Gd(DOPO )3 were 2.49, 3.61, and 7.90 μB, respectively, in good agreement with the 3+ 3+ 3+ expected magnetic moments, 2.53, 3.62, and 7.94 μB for Ce , Nd , and Gd cations (Figure [62,64-69] X). Upon cooling, the μeff values decreased steadily to 1.23, 1.97 and 6.49 μB, q respectively, at 2 K. Such decreases in moments at lower temperatures for Ce(DOPO )3 and q Nd(DOPO )3 results from the depopulation of Stark energy levels created by crystal field perturbations of the J = 5/2 and J = 9/2 manifold for the Ce3+ and Nd3+ cations, respectively. The q [62] behavior of Gd(DOPO )3 was consistent with that previously reported. Overall the magnetic data are consistent with monoanionic ligands that are in their quinone states (S= 0); therefore the q 3+ magnetic response of the Ln(DOPO )3 complexes arise solely from the paramagnetic Ln cations. With the corresponding lanthanide chemistry established, the same synthetic procedures 243 were extended to americium and californium. As for the lanthanide models, treating AmBr3 q q and HDOPO resulted in the formation of Am(DOPO )3. Due to the experimental obstacles associated with transuranic elements, characterization by 1H NMR spectroscopy was not possible; however, analysis of single crystals obtained from the analogous crystallization q conditions confirmed the molecular structure of Am(DOPO )3. In this case, the americium has three DOPOq ligands chelated to form a 9-coordinate distorted tricapped trigonal prismatic geometry shown in Figure 4.8. The Am-O distances range from 2.463(3) – 2.494(3) Å, as the anionic and dative interactions are averaged across each ligand. For comparison, pure dative

Am-O interactions range from 2.508(6)-2.525(4) Å in [Am(TMOGA)3][CLO4]3 (TMOGA = tetramethyl-3-oxa-glutaramide)[70] No pure anionic Am-O bonds were noted in the CCDC. The Am-N bond distances range from 2.545(3) – 2.591(3) Å, and are on par with those observed for [70] [Am(PDA)(NO3)(H2O)2]·H2O (H2PDA = 1,10-phenanthroline-2,9-dicarboxylic acid) of [28] 2.589(11) Å and Am(HDPA)3 of (2.551(4), 2.591(3), 2.550(4)), both of which are established 33 to contain a trivalent Am. The intraligand C-O bonds range from 1.265(5) - 1.276(5) Å and C-N bonds range from 1.321(5) – 1.342(5) Å, producing an average MOS value of -1.08(14) for the ligands. These intraligand bond metrics are in correspondence of published DOPOq distances for transition metals. Further characterization by electronic absorption spectroscopy on a single

q crystal of Am(DOPO )3 reveals absorbances for  to * transitions at 427 and 746 nm, which is q -1 -1 [54] in accord with the uranium derivative, UO2(DOPO )2 (λmax = 719 nm, 14,400 cm M ), q -1 -1 [59] q [64] KDOPO (THF) (λmax = 735 nm, 9,750 cm M ) and NaDOPO (λmax = 695 nm). The quinone form of the ligand typically shows large charge transfer bands in the 650-800 range due to transitions into an empty DOPOq -based π* orbital. These transitions are so intense that any features due to Americium are dwarfed (Figure 4.9). q With the successful synthesis of Am(DOPO )3, the berkelium and californium q q ,Bk(DOPO )3 & Cf(DOPO )3, was also targeted. The dissolution of BkCl3 in pyrindine with three equivalents produced a teal color solution which was observed with the lanthanides. After two hours, the solution darken, and eventually turning black. This was indicative that radiolysis was affecting the crystallization. The solution was reduced to a residue. The residue was redissolved in pyridine and 10 equivalents of HDOPOq was added. Within the hour, blue crystals formed. Crystallographic data reavealed the formation of Bk(DOPOq)3. The Bk-O bond distance ranges from 2.432(4) – 2.468(3) Å which are in similar to those in Bk(HDPA)3 system, 2.389(3) – 2.483 Å.27 The Bk – N distance ranges from 2.518(4) – 2.566(4) Å, which agrees with the Bk(HDPA)3 Bk – N bond range of 2.512-2.581Å. From this we can infer this is a Bk(III) center. Further investigating the Bk center, the UV-Vis-NIR spectrum figure 4.10 shows broad transition at and nm which are derived from the HDOPOq ligand. 249 Treating CfCl3 with three equivalents of HDOPO in pyridine produced the same striking color change from pale green to vibrant teal, indicative of the desired product. Subjecting this material to the same crystallization conditions resulted in isolation of crystals q of Cf(DOPO )2(py)(NO3), which was confirmed by X-ray diffraction analysis. In this case, two DOPOq ligands, one pyridine molecule, and one k2-nitrate fill the coordination sphere, generating a Cf center in the muffin geometry. Overall, the californium-ligand bond distances are in accord with a trivalent Cf. The Cf-O bond lengths, ranging from 2.404(3)-2.419(3) Å, are similar to 28 those reported for Cf(HDPA)3 (2.387(4) – 2.494(4) Å), which is established to contain a +3 q californium ion. The Cf-N distances of 2.496(4) and 2.527(4) Å in Cf(DOPO )2(py)(NO3) 34 correspond well to those in Cf(HDPA)3 of 2.508(4), 2.512(4), 2.545(4) Å. The intraligand distances for both DOPO ligands produce an average MOS value of -1.02(17), consistent with the quinone resonance form. This assertion is further corroborated by the electronic absorption spectrum, which shows the diagnostic transitions at 430 and 630 nm for charge transfers to the empty pi* orbitals of the quinone ligand. q Repeated attempts at isolation of crystals of Cf(DOPO )3 were unsuccessful, with crystals q of Cf(DOPO )2(py)(NO3) obtained every time. A high resolution mass spectrum of the starting 249 material, CfCl3, reveals no nitrate incorporation, thus the nitrate is presumably formed over the q course of the crystallization. This is clearly visible as the initial dark teal solution of Cf(DOPO )3 q changes to burgundy, signifying formation of Cf(DOPO )2(py)(NO3). Thus the nitrate is likely formed from radiolysis of the pyridine in the presence of water. As the nitrate concentration increases, the nitrate competes for the californium, disrupting the desired tris(chelate). Nitrate formation is not unprecedented in radiochemistry, as previous studies have shown that nitrate can 239 [72] form from radiolysis of N2 by Pu in water. Generation of the californium nitrate highlights that while non-aqueous chemistry can be performed with highly radioactive elements, crystallization conditions need to be tuned to deposit crystals readily to avoid radiolysis products. 4.3 Conclusion A series of tris DOPOq compound were synthesized and fully characterized. Crystallographic data revealed a bonding transition at Cf(DOPOq)(NO3)2 where the Cf-N and the Cf-O bonds were shorter than anticipated which was not observed in the lathanide series. The UV-Vis-NIR spectra were dominated by the DOPOq ligand however in the case of Cf, the spectrum exhibited broad charge transfer. As this has been seen in the borate and DPA system, this alluded to the metastable state of divalent californium. 4.4 Experimental All air and moisture manipulations were performed in an MBraun inert atmosphere drybox with an atmosphere of purified argon. Anhydrous pyridine (Sigma Aldrich) was used without further purification. 2,4,6,8-Tetra-tert-butyl-9-hydroxy-1H-phenoxazin-1-one (HDOPOq) was prepared according to literature procedure.

243 249 249 Caution! Am(t1/2=7380 years), Bk(t1/2= 364 days) and Cf(t1/2=351 years)represent serious health risks due to their a emission as the radiotoxicity associated with their , , and  emitting

35 daughters. All studies with these actinides were conducted in a laboratory dedicated to studies on transuranium elements. This laboratory is located in a nuclear science facility and is equipped with HEPA-filtered hoods and gloveboxes. A series of instruments continually monitor the radiation levels in the laboratory. All free-following actinide solids are handled in gloveboxes, and the products are only examined when coated with immersion or krytox oil. There are significant limitations in accurately determining yields of these actinide compounds because it requires to drying, isolating, and weighing a solid, which possess a inhalation hazard and manipulation difficulties given the small quantities of product from these reactions.

Single crystals of each compound were mounted on a Mitogen mounts with krytox oil and the crystals were optically aligned on a Bruker D8 Quest X-ray Diffractometer using a built-in camera. Preliminary measurements were performed using an Imus X-ray source ( Mo Ka, = 0.71073 A) with high-brillance and high-performance focusing quest multilayer optics. APEXIII software was used for solving the unit cells and data collection. The reflection’s intensities of a sphere were collected by a mixture of four sets of frames. Each set had a different omega angle for the crystal, and each exposure covered a range of 0.50 in , totaling to 1464 frames. The frames were collected with an exposure time of 5-25 second which was dependent on the crystal. SAINT software was used for data integraic including polarization and Lorentz corrections. PLATON was used to finalized the structure for any issues. CIFs are available from the Cambridge Crystallographic Data Centre (CCDC) and are given in the Supporting Information.

UV-vis- NIR data were collected for each compound using a Craic Technologies microspectrophotometer. Single crystals of each compound were paced on a quartz slide in immersion oil, and the data was collected from 300 nm to 1100 nm q General Procedure for Preparation of Ln(DOPO )3: A 20 mL scintillation vial was charged with anhydrous 0.114 mmol LnCl3 and 5 mL of pyridine. To this suspension was added a violet solution of HDOPOq (0.150 g, 0.343 mmol) in 5 mL of pyridine, resulting in a color change to dark blue after 5 minutes. After stirring for 2 hours, the resulting solution was concentrated in vacuo to a dark blue powder. The product was extracted into 20 mL of pentane, and the solution was filtered to remove the pyridinium chloride byproduct. This solution was concentrated in q vacuo, resulting in a blue powders assigned as (DOPO )3Ln (yields: 68-76%).

q 243 Preparation of Am(DOPO )3. A 7 ml scintillation vial was charged with AmBr3 (0.005 g, 0.0104 mmol) and 2 ml of pyridine. A solution of HDOPOq (0.0135 g, 0.0311 mmol) dissolved in 2 mL of pyridine was added to the vial, causing a color change from yellow to dark purple. The solution sat overnight to allow evaporation of solvent. Dark purple block crystals suitable for X-ray analysis formed, and were analyzed immediately. q 249 Preparation of Bk(DOPO )3. A 7 ml scintillation vial was charged BkCl3 (0.00433 g, 0.0104 mmol) and 2 ml of pyridine. A solution of HDOPOq (0.0450 g, 0.104 mmol) dissolved in 2 ml of pyridine was added to the vial, causing a color change from green to dark teal. The solution sat for a hour. Blue plate crystals suitable for X-ray analysis formed, and were analyzed immediately q 249 Preparation of Cf(DOPO )2(NO3)(py) A 7 ml scintillation vial was charged CfCl3 (0.005 g, 0.0104 mmol) and 2 ml of pyridine. A solution of HDOPOq (0.0135 g, 0.0104 mmol) dissolved in 2 ml of pyridine was added to the vial, causing a color change from green to dark teal. The solution sat overnight to allow evaporation of solvent. Teal plate crystals suitable for X-ray analysis formed, and were analyzed immediately.

4.5 Figures

q Figure 4.1. Synthetic scheme of Ln/AnX3 with HDOPO .

30000

) −1

25000

⋅ −1

20000

mol ⋅

15000 Gd(DOPO)3 Nd(DOPO)3 10000 Ce(DOPO)3

5000 Molar Absorbtivity (L Absorbtivity Molar

0 300 400 500 600 700 800 Wavelength (nm)

q Figure 4.2. Solution UV-Vis spectrum of Ln(DOPO )3 compounds.

Figure 4.3. Magnetic susceptibility of Ce(DOPOq)3 as a function of temperature. The measured q eff of the Ce(DOPO )3 at 300K is 2.49 B and at 2K it is 1.23 B.

Figure 4.4. Magnetic susceptibility of Nd(DOPOq)3 as a function of temperature. The measured q eff of the Nd(DOPO )3 at 300K is 3.61 B and at 2K it is 1.97 B.

Figure 4.5. Magnetic susceptibility of Gd(DOPOq)3 as a function of temperature. The measured q eff of the Gd(DOPO )3 at 300K is 7.90 B and at 2K it is 6.94 B.

1 Figure 4.6 H NMR spectrum of Ce(DOPOq)3.

Figure 4.7. 1H NMR spectrum of Nd(DOPOq)3.

Figure 4.8. 9-coordinate Tris An(DOPOq)3 (An: Am, Bk) structure. The tert-butyls were omitted for clarity.

Figure 4.9. 9-coordinate Cf(DOPOq)2(NO3)(py) structure. The tert-butyls were omitted for clarity.

1.2

0.8

0.6

0.4 Absorbance Absorbance (a.u.) 0.2

0 320 420 520 620 720 820 920 Wavelength (nm)

Figure 4.10. Solid state UV-Vis-NIR spectrum of Am(DOPOq)3.

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2 Absorbance Absorbance (a.u.)

0.1

0 320 420 520 620 720 820 920 Wavelength (nm)

Figure 4.11. Solid state UV-Vis-NIR spectrum of Bk(DOPOq)3.

1.6

1.4

1.2

0.8

0.6

Absorbance (a.u.) Absorbance 0.4

0.2

0 320 420 520 620 720 820 920 Wavelength (nm)

Figure 4.12. Solid state UV-Vis-NIR spectrum of Cf(DOPOq)2(NO3)(py).

CHAPTER 5

UNDERSTANDING THE SCARCITY OF THORIUM PEROXIDE CLUSTERS Shane S. Galley, Cayla E. Van Alstine, Laurent Maron, and Thomas E. Albrecht-Schmitt Inorg. Chem., 2017,56,12692-12694.

5.1 Introduction

Peroxide plays a key role in the extraction of uranium from ores possibly via the formation of uranyl peroxide clusters or uranyl carbonate peroxide complexes.[82,83] The nature of the interaction between uranyl and peroxide is unusually covalent and may provide an explanation for why the only known peroxide minerals, studtite and metastudtite persist over geological timescales.[84] The peroxide present in these minerals is generated from  radiolysis of water. In fact, the formation of actinide peroxides has been used to separate thorium from uranium for nearly five decades via the precipitation of a thorium peroxide compound while leaving the uranium in solution. Despite the utility of this method, this precipitate remains poorly characterized,[85-87] and a well-defined thorium peroxide compound or complex remains elusive. Herein we show that radiolytic reactions from aged sources of thorium with water lead to the formation of a trinuclear thorium peroxide cluster that can be isolated through the use of capping ligands that inhibit agglomeration and precipitation. 5.2 Results and Discussion

The reaction of Th(NO3)4·5H2O with three equivalents of 2,2´,6´,2´´-terpyridine in a 1:4 methanol:acetronitrile solvent mixture results in the formation of colorless tablets upon standing for two weeks. Single crystal X-ray diffraction studies revealed that the initial compound that crystallizes is the trinuclear cluster, [Th(O2)(terpy)(NO3)2]3·3CH3CN. Upon drying, this compound decomposes, and only Th(terpy)(NO3)4 could be identified in the residue (vide infra).

A view of the structure of [Th(O2)(terpy)(NO3)2]3 is shown in Figure 6.1 The cluster comprises

2 2 three [Th(O2)(terpy)(NO3)2] moieties that are bridged by -η :η peroxide anions. The presence of one tridentate and four bidentate ligands in the inner sphere creates a rare eleven coordinate environment around the Th(IV) centers that are best described as augmented sphenocorona. A similar [M3(O2)3] core has been observed in several Zr(IV) fluorides as well as in i [88,89] {Zr[MeC(N Pr)2]2(O2)}3. In the latter compound, it was established that the reduction of O2 44

2‒ to O2 is ligand based and appropriate ligand decomposition products are observed. However, this cluster is unstable in solution and ultimately decomposes to dimeric and polymeric oxo species via degradation of the peroxide anions. i In Zr[MeC(N Pr)2]2(O2)}3 the peroxide anions form by exposing a monomeric starting material to air at -30 °C. However, in the case of the formation of [Th(O2)(terpy)(NO3)2]3, reducing ligands or other peroxide-forming reagents are not present in the reaction, which suggests that the peroxide formation is radiolytic in origin. The issue with this postulate is that the half-life of 232Th is 1.4 × 1010 years, and from this basis alone it is challenging to argue that appreciable amounts of peroxide could be generated from 10 milligrams of Th(NO3)4·5H2O.

The key to solving this puzzle is age of the Th(NO3)4·5H2O used in the reaction, which turned out to be 40 years old without any intervening purification. 232Th is an  emitter and decays to 228 Ra (t½ = 5.75 y) followed by a series of very short-lived isotopes that ultimately decay to stable 208Pb. It is only takes 232Th 30 years to re-establish secular equilibrium after purification. Liquid scintillation counting of a dissolved sample of this old source of thorium revealed that it was undergoing more than three orders of magnitude more disintegrations per second than freshly 232 recrystallized Th(NO3)4·5H2O. Thus, while it is true that Th itself does not generate enough radiolysis products to account for appreciable peroxide formation, its short-lived daughters provide ample activity for these radiolytic reactions to occur. This also provides a word of caution against the laissez-faire attitude that is often exhibited when working with thorium.

The structure of [Th(O2)(terpy)(NO3)2]3 provides some important metrics for comparison with Zr(IV) peroxides as well as with the large family of U(VI) peroxide clusters. The angles at the bridging oxygen atoms of the peroxide anions averages 126.53(9)°. This angle has been examined in detail in uranyl peroxides, and the bending is sensitive to the counter ions employed to balance charge with the anions clusters.[90] In this case, the thorium peroxide clusters are neutral, and based on oxidation states, the Zr(IV) peroxide clusters provide a better source of comparison. An averaging of the Zr‒O2‒Zr angles in both the fluoride and amido clusters yields a comparable value to that found in the thorium cluster of 125.14(4)°. The O‒O bond distance is also quite similar between the Th(IV) and Zr(IV) compounds and averages 1.516(3) and 1.515(13) Å, respectively. It is interesting to note that while there is < 2° angular deviation between the Th(IV) and Zr(IV) peroxide binding that the Th‒O and Zr‒O bond distances differ substantially with averages of 2.369(2) Å and 2.162(10) Å, respectively. This observation is not surprising given the 45 large increase in ionic radius between Zr(IV) (0.86 Å) and Th(IV) (1.08 Å). These structural data point to largely ionic interactions in both the Th(IV) and Zr(IV) cluster. These observations are bolstered by DFT calculations as have been successfully applied to other Th(IV) complexes as well as much more complex open-shell actinide complexes such as those containing plutonium, berkelium, and californium.[27,28,91,92] The optimized geometry of the

[Th3(O2)3] cluster is in good agreement with determined by X-ray diffraction,14- indicating the adequacy of the computational methods to deal with this system. The ground state of the complex is found to be a closed-shell singlet spin in line with three Th(IV) centers. This was further confirmed by a f-in-core calculation (fixing the oxidation state of each Th center to +IV). A deep analysis of the bonding was then carried out. First, the molecular orbitals were scrutinized. While the LUMO is located on the terpy ligand, the highest occupied MOs are three combinations of π orbitals on the peroxide (see ESI HOMO, HOMO-1, and HOMO-2) without any interactions with the metal center. Bonding orbitals were found far lower in energy that involve a 6d orbital on Th and the π* of the peroxide as shown in Figure 2. Hence, unlike uranyl peroxide interactions, which make heavy use of the 5f orbitals, the only frontier orbital found to be involved in the [Th3(O2)3] cluster is the 6d. 2- The nature of the bonding orbital is in line with a donor-acceptor-type interaction between O2 and Th4+. This is further highlighted by the Natural Bonding Orbital (NBO) analysis.[93-104] In this analysis, interactions between the peroxide and the thorium centers were only found at the second- order donor-acceptor. Therefore, the interaction is predicted to be quite weak as substantiated by the Wiberg bond index that is only 0.3 for the Th-peroxide (slightly more than an agostic interaction). 5.3 Conclusion Taken together these experimental and computational results verify early findings from the thorium/uranium separations where it was observed that upon drying the thorium peroxide precipitate rapidly liberated oxygen.[104] Hence, the reason for the paucity of thorium peroxides in the literature can be ascribed to instability imparted by a largely ionic interaction between Th(IV) and peroxide that sets them apart from their covalent uranyl counterparts and places them in line with early transition metal analogs like Zr(IV).

5.4 Experimental

CAUTION! 232Th element is an alpha emitting radioisotope. Standard precautions should be followed while handling these chemicals.

Th(NO3)4·5H2O (0.010 g, 0.0297 mmol ) and 2,2’,2”,2’ terpyridine (0.0208 g, 0.0891 mmol) was dissolved in 5 mL of a 1:4 mixture of methanol:acetonitrile. The mixture was capped and allowed to stand for two months. Colorless tablets crystals were isolated and washed with ethanol.

X-ray structural analysis: [Th(O2)(terpy)(NO3)2]3: colorless tablet, crystals, P-1 (No. 2), Z = 2, a = 13.2177(12) Å, b = 13.9068(13) Å, c = 18.4265(17) Å,  = 86.9880(15),  = 88.0749(15),  = 3 ‒1 83.8940(16) , V = 3361.9(5) Å (T = 100 K), μ = 125.28 cm , R1 = 0.0269, wR2 = 0.0794. Bruker

APEXII Quazar diffractometer: θmax = 55.222°, MoKα, λ = 0.71073 Å, 0.5° ω scans, 50764 reflections measured, all reflections were included in the refinement. The data was corrected for Lorentz-polarization effects and for absorption, structure was solved by direct methods, anisotropic refinement of F2 by full-matrix least-squares, 48 parameters.[105]

5.5 Figures

Figure 5.1. . A view of the structure of the trinuclear thorium peroxide cluster, [Th(O2)(terpy)(NO3)2]3. The Th(IV) centers are eleven coordinate with augmented sphenocorona geometry that are bridged by -η2:η2 peroxide anions. The periphery of the cluster is capped by tridentate 2,2´,6´,2´´-terpyridine ligands. Hydrogen atoms on the terpy ligands have been omitted for clarity. Th = grey, O = red, N = blue, C= black.

Figure 5.2. A depiction of the weak donor-acceptor interaction between Th(IV) and a π* orbital of peroxide in [Th(O2)(terpy)(NO3)2]3.

CHAPTER 6

UNCOVERING THE ORIGIN OF DIVERGENCE IN THE CSM(CRO4)2 (M = LA ‒ SM; AM) FAMILY THROUGH BAND STRUCTURE ANALYSIS AND AN EXAMINATION OF THE CHEMICAL BONDING IN A MOLECULAR CLUSTER 6.1 Introduction

Actinides beyond plutonium often have 5f electrons that are largely localized as evidenced by the superconducting behavior of americium metal.[106,107] In contrast, earlier actinides from at least uranium to plutonium display itinerant 5f electron behavior in their metallic states that extends to molecules where hybridization of 5f orbitals with ligand orbitals and delocalization of 5f electrons can occur. [108-112] This situation is further complicated by several factors that include the near degeneracy and greater radial extension of empty 6d orbitals, additional frontier orbitals coming into play (6p, 7s, and 7p), and reorganization of all of these orbitals upon complexation.[113-117] Relativistic effects and spin-orbit coupling (SOC) dominate the electronic structure in these heavy elements,[27,118-122] and the magnitude of crystal- and ligand-field splitting lies between that found in the 4f series and 5d transition metals. This situation is often termed the intermediate coupling regime.[118] Taken together, understanding the chemistry and physics of 5f elements represents the outer limits of current experimental and theoretical approaches. These challenges must be undertaken nevertheless for fundamental reasons that include understanding the evolution of electronic structure across the periodic table, and for practical applications, such as mitigating the environmental effects of the Cold War and improving the utilization of nuclear energy.

There are radiologic and reaction-scale challenges that are inherent to working with actinides that lie beyond uranium that often force the use of benign analogs for these elements. Examples of this include replacing PuIV with CeIV or AmIII with EuIII. [27,117-125] These substitutions are often based on similar ionic radii.[123] However, the aforementioned changes in electronic structure and the increased involvement of frontier orbitals in the actinides creates dissimilarities between the 4f and 5f series that manifests in unexpected coordination chemistry, electronic properties, and reactivity. For example, the reactivity and coordination environments of cerium and plutonium diverge in phosphonates,[126-128] carboxypyridinonates,[132,133] and hydroxypyridinonates.[130,134-136] The enthalpy of complexation of AmIII by softer donors ligands is notably stronger than it is for EuIII and can be exploited for separating AmIII from 49 lanthanides in used nuclear fuel recycling.[115,137-142] Contracted M‒L bonds have also been measured and calculated in M[N(EPR2)2]3 complexes (M = U, Pu; E = S, Se, Te; R = Ph, iPr, H) that are consistent with enhanced covalency in An‒E bonds versus that found with lanthanides.41 Variance occurs not only between the 4f and 5f series, but also between early and late actinides.[27,28,30,143-149] Recent studies on the reduction of AnIII cyclopentadienyl complexes to AnII have shown bifurcation in the ground states of the resultant species with UII existing in a 5f n6d1 state (5f 36d1) state; whereas PuII adopts a 5f n+16d0 (5f 6) configuration.[46,150-152] These differences in bonding between actinides are further illustrated by UIV and PuIV β-ketoiminates where contributions from both 7s and 6d orbitals were found in the U‒O bonds; whereas the only metals-based orbitals participating in the Pu‒O bonds are the 6d orbitals.127 Rare examples of studies on the complexation of BkIII and CfIII have shown that the more negative bond enthaplies are the result of increased covalency, but the origin of this effect lies in the degeneracy of actinide 5f orbitals and ligand orbitals rather than significant orbital overlap.[28,145,153]

While many of the aforementioned examples have been pursued in order to provide a basic understanding of structure and bonding in f-element compounds, some of these materials are of practical importance and play roles in mitigating the environmental legacy of the Cold War. Among the components of nuclear waste of particular concern are large amounts of the mutagen, chromate, that is present in waste tanks because of its use in antiquated separations methods such as REDOX,[154] and as a corrosion inhibitor for the tanks themselves. Complicating matters further, chromates also forms undesirable inclusions in the form of spinels during vitrification of nuclear waste.[155] ThIV and UVI chromates have been the subject of numerous investigations and show a vast array structural topologies.[156-1162] However, both of these actinide cations are 5f 0, and therefore lack many of the interesting electronic characteristics found in later actinide compounds.

In contrast to thorium and uranium compounds, transuranium chromates are largely unexplored, and most examples that appear in the literature are poorly characterized. Among the few well characterized compounds is actually a rare example of a AmV compound, III [163,164] Cs3AmO2(Cr2O7)2·H2O, that was obtained via ozonation of Am . The most stable oxidation state of americium is III+ and is likely more relevant to americium speciation in tank waste. However, an AmIII chromate has yet to be reported. In order to address this issue, we

50 have undertaken the investigation of the synthesis, structure, and properties of AmIII chromates. These results are placed within the context of other trivalent f-element chromates by completing a comprehensive study of the LnIII compounds that form under the same conditions. [165-166] Here III we examine the CsLn(CrO4)2 (Ln = La ‒ Sm; Am) family of compounds and show that Am can form the same structure type as found with LnIII ions that possess similar ionic radii as well as a structure type not yet observed with lanthanides. We also show that the band gap for

CsAm(CrO4)2 is smaller than that observed for the lanthanides; necessitating an examination of the electronic structure of these compounds. The bonding is probed by both excising a cluster that describes the local coordination environment and via band-structure calculations. 6.2 Results and Discussion

CsLn(CrO4)2 (Ln = La, Pr, Nd, Sm) crystallize in the monoclinic space group P21/c and form layered structures. The layers are composed of lanthanide chromate chains that propagate 2- along the 21 screw parallel to the b axis. These chains comprise CrO4 tetrahedra that corner- and edge-share with LnIII polyhedra. LnIII cations bridge between the chains creating layers that extends parallel to the [bc] plane. Cs+ cations fill the interlayer space as illustrated in Figure 7.1.

RbLa(CrO4)2, RbPr(CrO4)2, and KLa(CrO4)2 are isotypic with these compounds and have been previously reported.[165-167] The LnIII centers are nine-coordinate with an approximate muffin geometry.[168] The 2- coordination environment contains nine oxygen atoms donated from CrO4 units, as shown in

Figure 7.2. For CsLa(CrO4)2, the La–O bond distances range from 2.474(4) to 2.589(4) Å. The lanthanide contraction is observed in this system with the Pr–O distances ranging from 2.422(3) to 2.558(3) Å. There are two crystallographically unique CrVI sites with Cr–O distances that 2- occur from 1.605(3) to 1.682(3) Å. The CrO4 tetrahedra are distorted, as evidenced by both these variable bond distances and non-ideal bond angles that range from 100.48(15)° to 112.84(17)°. Ln–O and Cr–O bond distances are provided in Table S3. Gradual symmetry reduction and ultimately collapse of the layers occurs as the LnIII ionic radii diminish. Beginning at NdIII the crystallographic symmetry is lowered to P2/c. However, the structure remains quite similar as shown in Figure 7.3. The rubidium analogs have been previously reported, but do not adopt the same structure type as those reported here.[169] As the ionic radii continues to contract the LnIII coordination number decreases from nine to eight and III III [124] Nd and Sm are found within LnO8 trigonal dodecahedra. A view of the local coordination 51

III III environment around the Nd and Sm cations is shown in Figure 7.2b. For CsNd(CrO4)2, the Nd‒O bond distances range from 2.381(2) to 2.573(2) Å. In accord with the lanthanide contraction, shorter Sm‒O bond distances are observed in CsSm(CrO4)2 and occur from 2.343(3) to 2.546(3) Å. The reason why these contractions are so obvious is that lanthanides are skipped between LaIII and PrIII and between NdIII and SmIII. In the former case, cerium is absent because in the presence of chromate it oxidizes to CeIV, and in the latter case promethium is radioactive with no long-lived isotopes. The NdIII and SmIII compounds contain only one 2‒ crystallographically unique CrO4 site and greater variance in Cr‒O bond distances is observed in these structures when compared to that observed for LaIII and PrIII. [165,170-177] The Cr‒O bond distances in CsNd(CrO4)2 and CsSm(CrO4)2 range from 1.616(2) to 1.692(2) Å and 1.609(3) to 2‒ 1.692(2) Å, respectively. Again the CrO4 tetrahedra are distorted with bond angles ranging from 101.42(13) to 112.61(13)°. Bond distances for CsNd(CrO4)2 and CsSm(CrO4)2 are given in Table S3.

Polymorphism in -CsAm(CrO4)2 and -CsAm(CrO4)2 is likely representative of small energetic differences between different structure types in this system. Similar polymorphism is

[174-184] also observed in M(IO3)3 (M = La ‒ Lu, Am, Cm, Bk, Cf). -CsAm(CrO4)2 is triclinic and not isotypic with any of the other compounds described in this work. In contrast,

III -CsAm(CrO4)2 is isomorphous with CsNd(CrO4)2 and CsSm(CrO4)2. The ionic radius of Am most closely matches that of NdIII and this latter result is expected.[123] The reduced symmetry of

-CsAm(CrO4)2 gives rise to two crystallographically-unique chromium centers that alter the layer composition from that observed in -CsAm(CrO4)2. The layers extend parallel to the [ab] plane and are composed of edge-sharing chains of AmIII polyhedra connected by alternating 2- 2- corner- and edge-sharing CrO4 tetrahedra (Cr1) and strictly corner-sharing CrO4 tetrahedra (Cr2), as shown in Figure 7.4. The AmIII cations in both structure types are eight-coordinate with the americium site in

-CsAm(CrO4)2 adopting a geometry best approximated by a bicapped trigonal prism. whereas the site in -CsAm(CrO4)2 closer to a trigonal dodecahedron. Both coordination environments

2- III are composed of eight oxygen atoms; seven CrO4 tetrahedral bind the Am centers in -

CsAm(CrO4)2 and six in -CsAm(CrO4)2 as shown in Figure 5. Average Am‒O bond lengths are 2.439 (4) Å in both structures. Selected bond distances are provided in Table F.3.

Absorption data were collected for all compounds from single crystals using a microspectrophotometer. Characteristic f-f transitions for the trivalent lanthanides are observed where expected for most of the lanthanide compounds.[185] These transitions are largely unperturbed by the coordination environment. Some f-f transitions are buried beneath the intense ligand-to-metal charge-transfer (LMCT) bands from chromate as shown in Figure S1. Analysis of the Cs2CrO4 starting material reveals only a CT band extending to 450 nm.

In contrast, the spectra of -CsAm(CrO4)2 and -CsAm(CrO4)2 feature an intense absorption feature extending through the visible spectrum to around 720 nm as shown in Figure 6; thus explaining the dark red color of the crystals. Characteristic intra-f transitions for AmIII 7 7 [186] are also present such as the F0→ F6 transition centered near 815 nm. Such strong absorption across the visible range in these compounds might be an indication of semiconducting behavior, and this was analyzed via an absorbance vs. optical energy plot shown provided in Figure 6.

In order to probe the nature of the Am–O bonding in -CsAm(CrO4)2 we utilize first molecular quantum chemistry at the hybrid DFT level (PBE0). The system studied contains a single Am site surrounded by seven CrO4 units; these atoms were fixed at their crystallographically determined positions. To balance the 11– charge this cluster carries, 11 Cs+ counterions were added and their positions optimized. The neutral molecular cluster thus analyzed was Am(CrO4)7Cs11, Cartesian atomic coordinates of which are given in the Supporting Information. Over the last few years there has been much debate about the nature of covalency in the

5f series. Perturbation theory holds that, to first order, the mixing of molecular orbitals 휙푖 and (1) 휙푗 is governed by the mixing coefficient 푡푖푗 :

(1) −퐻푖푗 푡푖푗 = µ , [1] 푒푖−푒푗 where the off diagonal elements of the Hamiltonian matrix 퐻푖푗 are related to the overlap between the orbitals, and the denominator is the difference between the corresponding energies. Thus, large orbital mixings can arise when 휙푖 and 휙푗 are close in energy, without there necessarily being significant spatial orbital overlap. The actinide community is now cognizant of the distinction between the more traditional overlap-driven covalency and energy-driven covalency

53 that arises from the near degeneracy of metal and ligand orbitals.[1,7] The latter is common in the transuranic elements; as the actinide series is crossed the 5f orbitals become energetically stabilized and radially more contracted. Thus, at a certain point (dependent on the metal and the supporting ligand set) they become degenerate with the highest lying ligand based functions, yet are too contracted for there to be significant spatial overlap. Table 2 presents the atomic orbital (AO) contributions to the 20 highest occupied  spin canonical Kohn-Sham molecular orbitals (MOs). They are composed of Am f and oxygen p character, and there is extensive mixing of metal and ligand AOs in many MOs. This is illustrated in Figures 7.7 and 7.8 which show, respectively, MOs 266 and 262. These images suggest that Am(CrO4)7Cs11 is a good example of energy-driven covalency, a conclusion reinforced by Natural Bond Orbital (NBO) analysis. The NBO approach is an orbital localization procedure, which attempts to recast the canonical Kohn-Sham orbital structure in terms of more chemically intuitive localized orbitals, emphasizing the Lewis-like molecular bonding pattern of electron pairs. Applying the technique to Am(CrO4)7Cs11 yields no Am–O NBOs. Furthermore, the NBO calculation yields six  spin orbitals which are all greater than 99.9% Am 5f in character, i.e., they are the six unpaired 5f electrons expected for an Am3+ center. This picture is very different from the delocalized nature of the Kohn-Sham orbitals, and suggests highly ionic Am‒O bonding. In support of this, the Natural and Mulliken spin densities are 5.93 and 6.02 respectively (very close to the 6 expected for an Am3+ ion). Furthermore, the expectation value of the 푆2 operator is ⟨푆2⟩ = 12.01; a pure heptet state would have is ⟨푆2⟩ = 12. Hence, these results indicates essentially zero spin contamination in the wavefunction. In principle, there is an infinite number of orbital representations we could chose to analyze. By contrast, the Quantum Theory of Atoms in Molecules (QTAIM) focuses not on orbitals but on the topology of the electron density, and allows us to analyze actinide covalency in an alternative way, ideally distinguishing energy-driven from overlap-driven effects; the former will not lead to a significant build-up of electron density in the internuclear region, while the latter should do so. [24,48, 187-189] The QTAIM states that there is a bond critical point (BCP) between every two atoms bonded to each other, with the BCP located at the minimum in the electron density along the bond path, the line of maximum electron density between the two atoms. The values of the electron and energy densities 휌 and 퐻, and 훻2휌, at the BCP can be used in analyzing the nature of the bond. Large 휌 values are associated with covalent bonds, and 54

퐻 is negative for interactions with sharing of electrons, with its magnitude indicating the covalency of the interaction. 훻2휌 is also generally significantly less than zero for covalent bonds. The delocalization index 훿 between two bonded atoms indicates the bond order between them.

As expected, QTAIM analysis of Am(CrO4)7Cs11 finds eight bond paths terminating at the Am center, one from each of the nearest neighbour O atoms. BCP data for these are given in Table F.5, together with the eight 훿 values. All of these metrics indicate very ionic Am–O bonding. The 휌 values are all well below the 0.1 e/bohr3 value generally taken as the upper limit for an ionic bond, and the significantly positive Laplacian data support this picture. The energy densities are all very close to zero, indicating no covalency, and the 훿(Am,O) data average less than 0.3.

In summary, the extent or otherwise of Am–O covalency in our Am(CrO4)7Cs11 cluster depends on one’s definition of the term. The canonical orbitals show extensive mixing between Am-5f and O-2p orbitals, but there is no significant overlap between them. There is thus very little build up of electron density in the internuclear region, and QTAIM analysis points to a very ionic picture. This view is reinforced by the NBO data, which find six fully localized 5f electrons and no Am–O bonding orbitals. We conclude that there is very little Am–O covalency in the sense that most chemists would recognize in terms of orbital overlap, but as we will show, degeneracy-driven covalency plays a major role in the properties of -CsAm(CrO4)2. Note that the SOC was not included in the cluster calculations presented above. As we are going to see in the next section, our band-structure calculations demonstrate that the SOC substantially influences the electronic structure of this material.

In order to investigate in further detail the electronic structure of this material in its lattice structure and, in particular, the nature of the Am-O chemical bond in the CsAmCrO4 crystal, we perform LDA+GA and LDA+DMFT band-structure simulations. The theoretical angle-resolved photoemission spectra and the corresponding f-electron spectral contribution to the density of states (DOS), that were computed utilizing the LDA+DMFT approach, are reported in Figure 9. While bare LDA predicts a band gap of 0.6 eV (not shown), the LDA+DMFT band gap is about 1.6 eV, which is in very good agreement with our absorption experiments. The band structure of the system displays pronounced incoherent features. In fact, the f-electron spectral weight is spread over a broad range of energies. Both the

55 large enhancement of the band gap with respect to LDA and the incoherent nature of the f- electron spectra constitute unequivocal evidence of the strong Am-5f electron correlations in this material. We observe also that most of the f spectral weight below the Fermi level is constituted by electrons with single-particle total angular momentum 푗 = 5/2  as expected, since the Am- 5f SOC is very strong. Interestingly, we find also that the lower Am-5f band and the O-2p bands are strongly hybridized. This fact constitutes a first clear indication that, in spite of the strong Am-5f electron correlations, the nature of the Am–O bonding is not purely ionic in this material. In order to characterize in further detail the nature of the Am–O chemical bond and the role of the strong f-electron correlations, we consider the local reduced density matrix of the Am-

5f electrons 휌푓, which is formally obtained from the ground state wavefunction of the solid by tracing out all degrees of freedom except the f shell of one of the Am atoms in the crystal. For this purpose, we conveniently utilize the LDA+GA approach. Let us represent 휌푓 as:

ρ푓 = ∑푖 푤푖 푟푖 , [2] where 푟푖 = 푃푖/Tr[푃푖], 푃푖 are projectors over the eigenspaces 푉푖 of 휌푓, and the probability weights

푤푖 are sorted in descending order. The eigenspaces 푉푖 have well-defined electron occupation 푁푖.

Furthermore, since the crystal field splittings are small in this material, the eigenspaces 푉푖 have approximately also a well-defined total angular momentum 퐽푖. On the other hand, the orbital angular momentum 퐿 and the spin angular momentum 푆 are not good quantum numbers, as the SOC of the Am-5f electrons is very strong. According to our LDA+GA calculations, the average number of f electrons per Am atom is 푛푓 = Tr[휌푓푁]~6.02. As shown in Table 4, the Am-5f electronic structure is dominated by a singlet with N = 6 electrons and total angular momentum 2 퐽 = 0, whose probability weight is 푤0 = 0.88. Interestingly, we find that Tr[푟0푆 ] = 2 Tr[푟0퐿 ] 2.25 × (2.25 + 1). This result indicates that the main reason why the Am-5f local electronic structure is dominated by a singlet is the SOC that is sufficiently strong to significantly contaminate the spin and orbital angular-momentum quantum numbers and to lift substantially the corresponding degeneracy in favor a 퐽 = 0 atomic singlet, in agreement with the third Hund's rule. We note also that the probability weight arising from other multiplets, besides the dominant 퐽2 = 0 singlet discussed above, is more than 10%. This information is consistent with [190,191] the value of the Am-5f entanglement entropy 푆푓 = Tr[휌푓ln [휌푓]], which is 0.72 according

56 to our calculations, while it would be 0 if 휌푓 was a pure singlet. These results clearly indicate that the Am-5f atomic degrees of freedom display non-negligible charge fluctuations. Consequently, they are entangled with the rest of the lattice, i.e., the f-electron contribution to the bonding is not purely ionic. In order to quantify the importance of the covalent contribution to the Am–O chemical bond, it is also interesting to compare the physical ground state energy of the system with the energy minimum realizable in a generic trial quantum state such that the Am-5f shell hosts exactly 6 electrons entirely disentangled from the rest of the system, i.e., a trial state such that the covalent contribution to the Am–O bond is exactly 0, by construction. Formally, such a trial state, which can be easily constructed within the LDA+GA framework, is realized by an electron many-body wavefunction of the form | 푖표푛 = | 5푓  |푒푛푣, where | 5푓 is the tensor product of all isolated Am-5f atomic states in the lattice, while |푒푛푣 is the most general wavefunction of the rest of the system. According to our calculations, such a trial state provides an energy higher by ∆퐸푐표푣1.85 푒푉 per unit cell with respect the physical ground state energy of the system. This result indicates clearly that the covalent energy contribution to the Am–O bond is not negligible in this material. In summary, our analysis indicates that the electron correlations are very strong in

-CsAm(CrO4)2. However, the electron correlations do not lead to the formation of a local moment, which is prevented by the strong SOC of the system, that favors a singlet atomic ground state with total angular momentum 퐽 = 0. Based on our calculations, we conclude that this material does not qualify as a Mott insulator, but as a strongly renormalized band insulator with strongly hybridized Am-5f and O-2p degrees of freedom, where the occupied f-electron band has mostly 푗 = 5/2 character. Consistently with this picture, our analysis indicates also that the nature of the Am–O chemical bond is not purely ionic, but has also a non-negligible covalent component. 6.3 Conclusion III In the case of the CsM(CrO4)2 family, the Am compounds diverge not because of significant orbital overlap and the formation of covalent bonds in the traditional sense, but rather because of the degeneracy of the AmIII and oxygen 5f and 2p orbitals, respectively, and the large SOC that prevents the formation of an Am-5f local moment. The strongly correlated nature of

AmIII is taken into account by both periodic and cluster DFT calculations, through the U,J parameters in the former and the use of hybrid DFT in the latter. The 5f and 2p degrees of freedom are entangled, and this significantly affects not only the electronic structure of AmIII, but also the energy contribution of the Am‒O bonds.

6.4 Experimental

243 Caution! Am (t1/2 = 7370 y) is an intense  emitter and also emits penetrating -rays up to 142 KeV in energy. Of equal importance, its -decay product is 239Np which is both short lived (t1/2 = 2.35 d) and an even more potent -ray emitter with energies up to 278 KeV. Studies on the bulk synthesis of americium compounds can only be conducted in an appropriately equipped radiologic facility. In this case, all studies were performed in a Category II nuclear hazard facility using moveable lead walls, lead bricks, thick lead sheets, respirators, and long 243 lead vests to protect researchers. AmO2 (98% purity) was obtained from Oak Ridge National

Laboratory. Ln(NO3)3·6H2O (La, Pr, Nd, Sm, Gd) (99.9%; Sigma Aldrich), Ln2O3 (Eu, Tb, Dy,

Ho, Er, Tm, Yb, Lu) (99.9%; Sigma Aldrich), Tb4O7 (99.9%; Sigma Aldrich), Cs2CrO4 (99.5%;

Sigma Aldrich), and Cs2Cr2O7 (99.5% Sigma Aldrich) were used as received.

CsLn(CrO4)2 (Ln = La, Pr, Nd, Sm) were prepared by loading 0.2 mmol of

Ln(NO3)3·6H2O (Ln = La, Pr, Nd, or Sm), 0.075 mmol of Cs2CrO4, and 0.075 mmol of

Cs2Cr2O7, and 2 mL of H2O into a 23 mL autoclave. The autoclaves were sealed and heated in a box furnace at 200 °C for 48 hours with a 48-hour cooling period following thereafter. The products were rinsed with water, and large, well-faceted gold (CsLa(CrO4)2) and yellow-orange

(CsPr(CrO4)2) offset prisms were isolated. The crystals of CsNd(CrO4)2 and CsSm(CrO4)2 formed green columns and gold plates, respectively.

Two different polymorphs of CsAm(CrO4)2 can be prepared using different synthetic conditions. -CsAm(CrO4)2 is prepared by first synthesizing Am(NO3)3·nH2O from AmO2.

Am(NO3)3·nH2O forms by reacting multiple 100 L aliquots of 5 M HNO3 with 0.02 mmol of

AmO2 and slowly fuming the mixture to dryness. A color change from black to light yellow is III III indicative of reduction to Am , and this putative Am nitrate along with 0.01 mmol of Cs2CrO4 and 0.01 mmol of Cs2Cr2O7, and 200 μL of water were loaded into the 10 mL PTFE autoclave. The autoclave was sealed and heated in a box furnace at 200 °C for 48 hours with a 48-hour

58 cooling period. Very dark red (nearly black) rods ~200 μm in length were isolated directly from the mother liquor. -CsAm(CrO4)2 was instead prepared with a hydrous AmCl3 starting material on a larger scale. A 24-hour digestion of 0.0358 mmol of AmO2 with 500 μL of 5 M HCl at 150 °C yielded a solution of AmIII. This solution was heated to dryness, after which 0.0179 mmol of

Cs2CrO4 and 0.0179 mmol of Cs2Cr2O7 and 500 μL of water were loaded into a 10 mL autoclave. The same heating profile was followed as used in the synthesis of -CsAm(CrO4)2.

Large, dark-red blocks of -CsAm(CrO4)2 were isolated after rinsing with water. Single crystals of all compounds were adhered to Mitogen loops with immersion oil and then mounted on a goniometer under a cold stream set at 100 K. The crystals were then optically aligned on a Bruker D8 Quest X-ray diffractometer using a digital camera. Diffraction data were obtained by irradiating the crystals with an IμS X-ray source (Mo Kα, λ = 0.71073 Å) with high- brilliance and high-performance focusing multilayered optics. Bruker software was used for determination of the unit cells, data collection, and integration of the data. Lorentz, polarization, and absorption corrections were applied. A hemisphere of data was collected for all crystals. The structure was solved by direct methods and refined on F2 by full-matrix least-squares techniques using the program suite SHELXTL.[192] Structure factors for americium are not present in the SHELX software and a new SFAC command must be added to the instructions file that defines the scattering factors for americium. Some of these compounds crystallize in less common space groups and the solutions were checked for missed symmetry using PLATON.[193] The Crystallographic Information Files (CIF) are available from the Cambridge Crystal Structure

Database Center: 1571937 (-CsAm(CrO4)2), 1571730 (-CsAm(CrO4)2), 1571731

(CsLa(CrO4)2), 1571733 (CsNd(CrO4)2), 1571732 (CsPr(CrO4)2), 1571734 (CsSm(CrO4)2). Selected crystallographic data are provided in Table S1 and S2. We have simplified the formula to CsM(CrO4)2. In some cases, the formula are more correctly (crystallographically) expressed as Cs2M2(CrO4)4.

Single crystals of each compound were placed on quartz slides under medium viscosity Krytox oil. A Craic Technologies microspectrophotometer was used to collect optical data in the UV-vis-NIR region.

Magnetism measurements were performed on polycrystalline sample of -CsAm(CrO4)2 using a Quantum Design MPMS under an applied field of 10 kOe for 4 K < 300 K. The 59 americium sample was sealed inside two, different, custom-built Teflon capsules. The first capsule has a piston design and fits inside of the second capsule that screws closed and is also taped to ensure that it cannot open during data collection. Datasets were collected with the capsules both empty and full, and the background from the sample holder was subtracted from the signal. Diamagnetic corrections were also applied.

DFT calculations were performed on a cluster representation of -CsAm(CrO4)2, as discussed in the main text. The Gaussian 09 code, revision D.01 was employed.[193] A (14s 13p 10d 8f 5g)/[10s 9p 5d 4f 3g] segmented valence basis set with Stuttgart-Bonn variety, 60- electron relativistic pseudopotential was used for Am,[194,195] and a (7s 6p)/[5s 4p] basis set plus the 46-electron relativistic pseudopotential for Cs.[196] Dunning’s cc-pVTZ basis set was used for Cr and O. The PBE0 functional was used,[197] in conjunction with the ultrafine integration grid. The SCF convergence criterion was set to 10–6, and the geometry convergence criterion was relaxed slightly from the default using iop(1/7=667), which produces 10-3 au for the maximum force.

QTAIM analyses were performed using the AIMALL program package,[198] with.wfx files generated in Gaussian 09 used as input. NBO analyses were performed with the NBO6 code,[199]

The electronic structure of -CsAm(CrO4)2 was investigated utilizing the Local Density Approximation (LDA) [200] in combination with dynamical mean field theory (LDA+DMFT)[201- 204] and in combination with the Gutzwiller Approximation (LDA+GA).[205-207] Both of these computational approaches are powerful tools widely used to study strongly-correlated electron systems that enables us to take into account the strong Am-5f electron correlations in - [208-210] CsAm(CrO4)2. We utilize the DFT code WIEN2K, and employ the standard fully- localized limit form for the double-counting functional. The LAPW interface between LDA and DMFT/GA employed in our calculations was implemented as described in Ref. [210]. The LDA+DMFT simulations are performed utilizing the Continuous Time Quantum Monte Carlo (CTQMC) impurity solver [211] at T = 580 K. Consistently with previous work,[202] we assume that the Hund’s coupling constant is J = 0.7 eV and that the value of the screened Coulomb interaction strength is U = 6.0 eV. Since our experiments have all been performed above the

Neél temperature of the system, in our simulations we assume from the onset a paramagnetic wavefunction, i.e., a solution that does not spontaneously break the symmetry of the system. Spin-orbit coupling is fully taken into account in our calculations.

6.5 Figures

1.4

1.2

1 CsNd(CrO4) 2 0.8 CsLa(CrO4)

0.6 2 Absorbance (a.u.) 0.4

0.2

0 300 400 500 600 700 800 900 1000

Wavelength (nm)

Figure 6.1. The solid state UV-Vis-NIR absorption spectra of Cs2CrO4, CsNd(CrO4)2, and CsLa(CrO4)2 from 300 nm to 1000nm.

a) b)

Figure 6.2. Polyhedral representations of CsLa(CrO4)2. (a) View along the c axis showing stacking of the lanthanum chromate layers with Cs+ cations in the interlayer space. (b) Depiction of part of 1‒ 3+ 2‒ a single [La(CrO4)2] layer. La is represented as blue polyhedra, CrO4 as orange tetrahedra, and Cs+ as tan spheres. 61

a) b )

3+ Figure 6.3. a) Nine-coordinate environment of the La cations in CsLa(CrO4)2 with an 3+ 3+ approximate muffin geometry. b) Coordination environment of Nd and Sm in CsLn(CrO4)2 2- (Ln: Nd,Sm), with O atoms shown as red spheres, but with CrO4 tetrahedra omitted for clarity. 2- All O atoms are donated from CrO4 moieties.

a) b)

Figure 6.4. Polyhedral representations of the structure of CsNd(CrO4)2. (a) A view along the b 1‒ 3+ axis showing the interlayer channels. (b) Depiction of part of a [Nd(CrO4)2] layer. Nd is 2- + represented as gold polyhedra, CrO4 as orange tetrahedra, and Cs as tan spheres.

62 a) b )

Figure 6.5. Polyhedral representations of -CsAm(CrO4)2. (a) View down the b axis showing the interlayer channels. (b) Single layer of one of the two-dimensional sheets. Am3+ is represented as 2- + dark red polyhedra, CrO4 as orange tetrahedra, and Cs as tan spheres.

a) b)

3+ 3+ Figure 6.6. Coordination environment of Am in CsAm(CrO4)2 with Am represented as dark 2- + red polyhedra, CrO4 as orange tetrahedra, and Cs as tan spheres. (a) -CsAm(CrO4)2. (b)

-CsAm(CrO4)2.

Figure 6.7. Solid-state UV-Vis-NIR absorption spectrum of -CsAm(CrO4)2 and -CsAm(CrO4)2 from 320 nm to 1200 nm. Inset: Absorbance vs. Optical Energy plot of -CsAm(CrO4)2 showing a band gap of ~ 1.65 eV.

Figure 6.8. MO 266. Isovalue = 0.035. Dark red and green are the phases of the wavefunction. Grey spheres = Cr, red spheres = O, purple spheres = Cs. The Am atom is in the center of the image. 

Figure 6.9. MO 262. Isovalue = 0.035. Dark red and green are the phases of the wavefunction. Grey spheres = Cr, red spheres = O, purple spheres = Cs. The Am atom is in the center of the image.

Figure 6.10. LDA+DMFT angle resolved photoemission spectra computed at T = 580 K. The corresponding 5/2 and 7/2 Am-5f spectral contributions are displayed in the right panel.

CHAPTER 7 CONCLUSION The body of work presented throughout this dissertation has given insight on non- aqueous transuranic chemistry, specifically focusing on the heavier trivalent actinides. This field of chemistry is underdeveloped due to the scarcity and the difficultly of handling these elements, however progress has been made to understand behavior of these elements in non-aqueous conditions. The overall goal was to provide structural data for understanding the selectivity observed in separations and the f-orbital participation in bonding. By utilizing the softer donor ligands, terpyridine, phenanthroline, and dithiocarbamate, gave insight to why there is a preference of trivalent actinides over lanthanides.

In the terpyridine system, the terpy molecules coordinate to the Am center differently which is due to the packing of iodides in the crystal lattice and the flexibility of the terpy molecule. The broad charge transfer observed in the Am(terpy)3 spectrum which may be due to -anion interaction, however other phenomena should not be ruled out. In comparison to the

Am(DTC)3(phen) system, the Am-N of the Am-terpy is shorter than the Am-N bond in the Am- phen bond. This may be due to the constraining of the terpy molecule around the Am center. As computational studies are being performed, nothing can be said of the f orbital participation in bonding.

The synthesis of the An(DTC)3(phen) systems crystalized in a very short time which allowed full characterization of these compounds before radiolysis destroy the samples. Crystallographic studies showed a major decrease across the An-N bond where as the An-S decreased as expected. Computational studies revealed there was no orbital mixing in the An-N bond but there orbital mixing observed in the An-S bond. The An-S bond did have a slight degree of covalency which elongated the An-N bond. Preliminary results of Es(DTC)3(phen) were collected but due to radiolysis no further characterization could be performed.

A series of tris DOPOq compound were synthesized and fully characterized. The purpose of using HDOPO was its ability to accept extra electron density by having an orbital * orbitals. Crystallographic data revealed Ln/An(DOPOq)3 complexes. However the synthesis of CfCl3 and q HDOPO had led to a different product, Cf(DOPO )2(NO3)(py), which was formed by radiolysis.

In the Bk(DOPOq), also showed evidence of radiolysis by solution changing from the teal blue to a black solution in a matter of hours.

A bonding transition at Cf(DOPOq)2(NO3)(py) where the Cf-N and the Cf-O bonds were shorter than anticipated which was not observed in the lanthanide series. The UV-Vis-NIR spectra were dominated by the DOPOq ligand however in the case of Cf, the spectrum exhibited broad charge transfer. As this has been seen in the borate and DPA system, this alluded to the metastable state of divalent californium. Overall, these systems provided fundamental synthetic challenges when working with the heavier actinides in non-aqueous media. As radiolysis should be factored in when developing systems for complexing the heavier actinides. Radiolysis is not factor in the 4f and the earlier 5f elements they do not provide to be good models for the later actinides. That being said, if the crystallizations are quick enough, radiolysis will not affect the synthesis which was seen in the terpy and DTC systems. Despite the synthetic challenges, this work provided structural data and bonding information on the late actinides. The data collected supported and provided evidence to what is being observed in solution and other solid-state studies. The softer donor systems are crucial for understanding the fundamental chemistry of the late actinides because it directly relates to separations of radioisotopes in the nuclear fuel cycle. With the hope of this work being establish, this field can advance to difficult ligand systems to probe the f-orbitals and develop a more rounded understanding of their participation in bonding.

APPENDIX A TABLES FROM CHAPTER 2

Table A.1. Crystallographic data Ln(terpy)3I3 compounds. Compound Ce(terpy)3I3 Pr(terpy)3I3 Nd(terpy)3I3 Sm(terpy)3I3

Formula Mass 1244.25 1224.74 1250.76 1256.87

Yellow, Yellow, Yellow, Yellow, Color, habit block block block block Space group R3 R3 R3 R3 a (Å) 12.653 (4) 12.648 (3) 12.6123(14) 12.5606(13) b (Å) 12.653 (4) 12.648 (3) 12.6123(14) 12.5606(13) c (Å) 28.187 (10) 28.262 (7) 28.3170(3) 28.441 (3)

90 90 90 90 α(°) β (°) 90 90 90 90

γ (°) 120 120 120 120

V (Å3) 3908(3) 3915(2) 3900.9(10) 3885.9(9)

Z 3 3 3 3

273 273 273 273 T (K) λ (Å) 0.71073 0.71073 0.71073 0.71073

Maximum 2θ (°) 54.996 55.002 54.874 55.098

3 ρcalc (g/cm ) 1.586 1.611 1.558 1.597

μ (Mo Kα) (cm–1) 27.22 29.60 28.05 28.17

R(F) 0.0812 0.0835 0.0605 0.0591 2 2 a for Fo > 2σ(Fo )

2 b Rw(Fo ) 0.2452 0.2263 0.1794 0.1647

Table A.2. Crystallographic data of Am(terpy)3I3

Table 1. Crystallograpic Data for Am(terpy)3I3 Complexes

Compound Am(terpy)3I3 2MeCN Am(terpy)3I3

Formula Mass 1405.60 1323.50 Color and habit Yellow, Block Yellow, Prism Space group Pcca R3 a (Å) 19.148(3) 12.586 (9) b (Å) 16.499(2) 12.586 (9) c (Å) 14.6038(19) 28.210 (19) α(°) 90 90 β (°) 90 90 γ (°) 90 120 V (Å3) 4613.7 (10) 3870 (6) Z 4 3 T (K) 130 130 λ (Å) 0.71073 0.71073 Maximum 2θ (°) 55.006 54.874

3 ρcalc (g/cm ) 2.024 1.704 μ (Mo Kα) (cm–1) 37.19 33.18

2 2 a R(F) for Fo > 2σ(Fo ) 0.0444 0.0841

2 b Rw(Fo ) 0.1325 0.2118

RF   Fo  Fc  Fo

1 2 2 2  2 2 4  R F   w F  F   wF w  o     o c   o 

Table A.3. Selected bond lengths for Ln(terpy)3I3

Selected Bond Lenghts for Ln(terpy)3I3 compounds (Å) Ce(terpy)3I3 Pr(terpy)3I3 Nd(terpy)3I3 Ce-N(1) 2.643 (15) Pr-N(1) 2.634 (11) Nd-N(1) 2.638(11)

Ce-N(1) 2.633 (15) Pr-N(1) 2.641 (10) Nd-N(2) 2.624(11) Ce-N(1) 2.672 (15) Pr-N(1) 2.644 (11) Nd-N(3) 2.629(11)

Sm(terpy)3I3 Sm-N(1) 2.607 (17) Sm-N(1) 2.594(15) Sm-N(1) 2.601(16)

Table A.4. Selected bond lengths for Am(terpy)3I3

Select Bond Lengths for Am(terpy)3I3 compounds (Å)

-Am(terpy)3I3 -Am(terpy)3I3 Am-N(1) 2.63(2) Am-N(1) 2.596 (5) Am-N(1) 2.64(2) Am-N(2) 2.593 (5)

Am-N(1) 2.63(2) Am-N(3) 2.570 (5) Am-N(4) 2.657 (5) Am-N(5) 2.608 (6)

APPENDIX B TABLES FOR CHAPTER 3 Table B.1. Crystallographic table for An(DTC)3(phen) compounds Cf(DTC)3(phen) Compound Am(DTC)3(phen) MeCN

Formula Mass 867.98 916.10

Color and habit Yellow, rods Green, rods

Space group P21/c P21/c a (Å) 16.9165(8) 10.4360(12) b (Å) 10.3587(5) 34.561(4) c (Å) 18.5943(9) 11.3259(14)

α(°) 90 90

β (°) 96.973(1) 117.142(3)

γ (°) 90 90

V (Å3) 3305.04 3635.2(8)

Z 4 4

T (K) 130 130

λ (Å) 0.71073 0.71073

Maximum 2θ (°) 52.744 55.202

3 ρcalc (g/cm ) 1.744 1.674

μ (Mo Kα) (cm–1) 27.25 27.03

2 2 a R(F) for Fo > 2σ(Fo ) 0.0199 0.0526

2 b Rw(Fo ) 0.0443 0.1083

Table B.2. Selected Bond lengths (Å) for An(DTC)3(phen).

Am(DTC)3(phen) Cf(DTC)3(phen) Am---N(1) 2.598(2) Cf---N(3) 2.540 (6) Am---N(2) 2.609(2) Cf---N(4) 2.572 (6) Am---S (1) 2.8015(8) Cf---S (1) 2.837 (2) Am---S (2) 2.9304 (8) Cf---S (2) 2.805 (2) Am---S(3) 2.8757 (8) Cf---S (3) 2.795 (2) Am---S(4) 2.8530 (7) Cf---S (4) 2.8186(19) Am---S(5) 2.8673 (8) Cf---S (5) 2.8508 (19) Am---S(6) 2.9193 (8) Cf---S (6) 2.9066(19)

6 Table B.3. SF and SO splitting of the H15/2 ground multiplet derived from a CAS(11,8) wavefunction. SF SO

CASSCF NEVPT2 CASSCF NEVPT2 0.0 0.0 0.0 0.0 75.5 77.1 0.0 0.0 164.8 124.3 254.8 252.1 288.9 270.6 254.8 252.1 343.8 287.0 484.7 503.7 578.7 567.2 484.7 503.7 674.9 752.8 866.1 879.7 724.3 773.8 866.1 879.7 795.6 813.7 1163.8 1172.7 1146.8 1166.3 1163.8 1172.7 1161.8 1193.1 1970.0 2011.3

1970.0 2011.3

2381.7 2466.6

3469.8 3585.6

2 Table. B.4. QTAIM parameters derived from a CASSCF wavefunction. BCP(r) and  BCP(r) correspond to the electron density and laplacian of the electron density at the bond critical point, HBCP corresponds to the energy density point and BCP is the electron delocalization index. All values are in a.u. 2 BCP(r)  BCP(r) HBCP BCP Cf-N1 0.041 0.184 0.001 0.212 Cf-N2 0.045 0.181 0.001 0.203 Cf-S1a 0.043 0.121 -0.004 0.306

Cf-S2a 0.040 0.111 -0.003 0.268 Cf-S1b 0.042 0.117 -0.004 0.289 Cf-S2b 0.035 0.087 -0.003 0.245

Cf-S1c 0.045 0.123 -0.004 0.316 Cf-S2c 0.040 0.110 -0.003 0.262

APPENDIX C TABLES FROM CHAPTER 4

q Table C.1. Crystallographic table of Ln(DOPO )3 complexes. q q q Compound Ce(DOPO )3 Nd(DOPO )3 Gd(DOPO )3

Formula Mass 1634.18 1770.43 1783.42

Color and habit Black, Plate Blue, block Blue, block

Space group P-1 P21/n P21/n a (Å) 13.8196(15) 14.4599(2) 14.410(3) b (Å) 14.4869(16) 26.1103(4) 26.353(5) c (Å) 24.637(3) 25.9352(5) 25.890(5)

α(°) 74.072(3) 90 90

β (°) 78.911(3) 100.6937(14) 100.82 (3)

γ (°) 74.159(3) 90 90

V (Å3) 4526.0(9) 9621.8(3) 9657(3)

Z 2 4 4

T (K) 100(2) 100(2) 150(2)

λ (Å) 0.71073 1.54178 0.71073

Maximum 2θ (°) 56.564 72.361 59.054

3 ρcalc (g/cm ) 1.199 1.222 1.227

μ (Mo Kα) (cm–1) 5.59 4.581 7.46

2 2 a R(F) for Fo > 2σ(Fo ) 0.0564 0.0614 0.0375

2 b Rw(Fo ) 0.0950 0.1693 0.0814

q Table C.2. Crystallographic table for An(DOPO )3 complexes.

q q q Compound Am(DOPO )3 Bk(DOPO )3 Cf(DOPO )3

Formula Mass 1873.21 1875.1 1875.17

Color and habit Dark purple, block Blue, Rod Blue, plate

Space group P21/n P21/n P21/n a (Å) 14.4261(19) 14.433 (2) 14.3744(7) b (Å) 26.258(4) 26.291 (4) 26.2457(12) c (Å) 25.840(3) 25.768 (4) 25.7763(12)

α(°) 90 90 90

β (°) 100.663(3) 100.908 (4) 100.6914(10)

γ (°) 90 90 90

V (Å3) 9619(2) 9601(3) 9555.7(8)

Z 4 4 4

T (K) 131(2) 100(2) 131(2)

λ (Å) 0.71073 0.71073 0.71073

Maximum 2θ (°) 55.192 55.204 55.284

3 ρcalc (g/cm ) 1.291 1.297 1.303

μ (Mo Kα) (cm–1) 8.56 9.09 9.46

2 2 a R(F) for Fo > 2σ(Fo ) 0.0400 0.0548 0.0354

2 b Rw(Fo ) 0.1136 0.1087 0.0787

Table C.3. Table of selected bond lengths for Ln/An DOPO complexes. (Å)

q q q q q q Ce(DOPO )3 Nd(DOPO )3 Gd(DOPO )3 Am(DOPO )3 Bk(DOPO )3 Cf(DOPO )2(NO3)(py) M-O1 2.4825(19) 2.463 (3) 2.4276(17) 2.488(3) 2.457(4) 2.419(2) M-O3 2.5204(19) 2.489(3) 2.4484(16) 2.463(3) 2.432(4) 2.411(2) M-O4 2.5058(19) 2.492(3) 2.4514(15) 2.493(3) 2.468(3) 2.380(15) M-O6 2.5234(18) 2.470(3) 2.4295(16) 2.474(3) 2.453(3) 2.455(13) M-O7 2.5073 (17) 2.473(3) 2.4316(17) 2.472(3) 2.446(4) M-O9 2.4934(19) 2.474(3) 2.4206(15) 2.482(3) 2.453(4) M-N1 2.644(2) 2.570(4) 2.5426(19) 2.554(3) 2.518(4) 2.518(3) M-N2 2.653(2) 2.608(4) 2.5527(19) 2.591(3) 2.566(4) 2.539(13) M-N3 2.634(2) 2.587(4) 2.514(2) 2.582(3) 2.542(4)

q Table C.4. Metrical oxidation states table of Ce(DOPO )3.

Ce(DOPOq)3 C1-N C2-O C1-C2 C2-C3 C3-C4 C4-C5 C5-C6

1.325 1.274 1.455 1.432 1.367 1.433 1.373

1.327 1.271 1.453 1.428 1.374 1.429 1.368

1.321 1.269 1.455 1.426 1.376 1.432 1.369

1.337 1.268 1.453 1.437 1.376 1.428 1.376

1.327 1.271 1.451 1.436 1.371 1.425 1.374

1.324 1.273 1.462 1.42 1.379 1.435 1.371

1 and 2 average 1.326 1.2725 1.454 1.43 1.3705 1.431 1.3705

3 and 4 average 1.329 1.2685 1.454 1.4315 1.376 1.43 1.3725

5 and 6 average 1.3255 1.272 1.4565 1.428 1.375 1.43 1.3725

overall average 1.3268333 1.271 1.4548333 1.4298333 1.3738333 1.4303333 1.3718333

Table C.4. continued

Ce(DOPOq)3 MOS ESD

1 and 2 average -1.0716547 0.14116312

3 and 4 average -1.0936354 0.14714486

5 and 6 average -1.0928811 0.15629066

overall average -1.0860571 0.14646876

q Table C.5. Metrical oxidation states table of Nd(DOPO )3.

q Nd(DOPO )3 C1-N C2-O C1-C2 C2-C3 C3-C4 C4-C5 C5-C6

1.334 1.275 1.434 1.45 1.368 1.429 1.387

1.313 1.278 1.477 1.43 1.382 1.442 1.379

1.33 1.263 1.46 1.44 1.377 1.421 1.379

1.313 1.269 1.454 1.437 1.375 1.434 1.375

1.343 1.265 1.451 1.443 1.371 1.437 1.362

1.315 1.272 1.462 1.436 1.387 1.423 1.368

1 and 2 average 1.3235 1.2765 1.4555 1.44 1.375 1.4355 1.383

3 and 4 average 1.3215 1.266 1.457 1.4385 1.376 1.4275 1.377

5 and 6 average 1.329 1.2685 1.4565 1.4395 1.379 1.43 1.365

1.3246666 1.2703 1.45633333 1.4393333 1.3766666 1.431 1.375 overall average 67 33333 3 33 67

Table C.5. continued

Nd(DOPOq)3 MOS ESD

1 and 2 average -1.112244 0.18991777

3 and 4 average -0.9835835 0.18242581

5 and 6 average -1.0125127 0.12450448

overall average -1.0361134 0.15863775

q Table C.6. Metrical oxidation states table of Gd(DOPO )3.

Gd(DOPOq)3 C1-N C2-O C1-C2 C2-C3 C3-C4 C4-C5 C5-C6

1.329 1.268 1.461 1.437 1.381 1.436 1.366

1.335 1.272 1.447 1.441 1.367 1.424 1.37

1.329 1.278 1.455 1.436 1.368 1.428 1.374

1.332 1.274 1.457 1.434 1.367 1.436 1.382

1.321 1.278 1.454 1.43 1.374 1.44 1.382

1.337 1.283 1.448 1.427 1.367 1.439 1.374

1 and 2 average 1.332 1.27 1.454 1.439 1.374 1.43 1.368

3 and 4 average 1.3305 1.276 1.456 1.435 1.3675 1.432 1.378

5 and 6 average 1.329 1.2805 1.451 1.4285 1.3705 1.4395 1.378

overall average 1.3305 1.2755 1.4536666 1.4341666 1.3706666 1.4338333 1.3746666

.Table C.6. continued

Gd(DOPOq)3 MOS ESD

1 and 2 average -1.061625804 0.111128558

3 and 4 average -1.131652098 0.144908188

5 and 6 average -1.194950884 0.165172433

overall average -1.129409595 0.135321822

q Table C.7. Metrical oxidation states table of Am(DOPO )3.

Am(DOPOq)3 C1-N C2-O C1-C2 C2-C3 C3-C4 C4-C5 C5-C6

1.326 1.279 1.451 1.433 1.373 1.433 1.371

1.326 1.282 1.46 1.423 1.374 1.426 1.373

1.337 1.266 1.465 1.435 1.386 1.424 1.381

1.328 1.266 1.461 1.44 1.376 1.439 1.361

1.321 1.27 1.454 1.434 1.376 1.44 1.369

1.34 1.275 1.457 1.437 1.375 1.423 1.382

1 and 2 average 1.326 1.2805 1.4555 1.428 1.3735 1.4295 1.372

3 and 4 average 1.3325 1.266 1.463 1.4375 1.381 1.4315 1.371

5 and 6 average 1.3305 1.2725 1.4555 1.4355 1.3755 1.4315 1.3755

1.3296666 1.273 1.458 1.4336666 1.3766666 1.4308333 1.3728333 overall average 67 67 67 33 33 . Table C.7. continued

Am(DOPOq)3 MOS ESD

1 and 2 average -1.1543668 0.14996668

3 and 4 average -1.0060078 0.14714958

5 and 6 average -1.101111 0.14346768

overall average -1.0871619 0.14109934

q Table C.8. Metrical oxidation states table of Bk(DOPO )3.

Bk(DOPOq)3 C1-N C2-O C1-C2 C2-C3 C3-C4 C4-C5 C5-C6

1.332 1.293 1.452 1.418 1.376 1.429 1.37

1.337 1.265 1.467 1.435 1.377 1.438 1.366

1.331 1.28 1.462 1.422 1.377 1.426 1.377

1.335 1.263 1.462 1.44 1.371 1.437 1.376

1.32 1.26 1.455 1.439 1.385 1.434 1.367

1.347 1.274 1.447 1.441 1.362 1.43 1.368

1 and 2 average 1.3345 1.279 1.4595 1.4265 1.3765 1.4335 1.368

3 and 4 average 1.333 1.2715 1.462 1.431 1.374 1.4315 1.3765

5 and 6 average 1.3335 1.267 1.451 1.44 1.3735 1.432 1.3675

overall average 1.3336666 1.2725 1.4575 1.4325 1.3746666 1.4323333 1.3706666

Table C.8. continued

Bk(DOPOq)3 MOS ESD

1 and 2 average -1.1916661 0.12474837

3 and 4 average -1.0905175 0.14831036

5 and 6 average -1.0342541 0.11397645

overall average -1.1054792 0.1202157

q Table C.9. Metrical oxidation states table of Cf(DOPO )2(NO3)(py).

q Cf(DOPO )2(N O3)(py). C1-N C2-O C1-C2 C2-C3 C3-C4 C4-C5 C5-C6

1.328 1.274 1.446 1.429 1.378 1.418 1.376

1.319 1.275 1.445 1.433 1.384 1.427 1.372

1.326 1.275 1.441 1.436 1.377 1.415 1.359

1.327 1.286 1.436 1.431 1.375 1.431 1.372

1 and 2 average 1.3235 1.2745 1.4455 1.431 1.381 1.4225 1.374

3 and 4 average 1.3265 1.2805 1.4385 1.4335 1.376 1.423 1.3655 overall average 1.325 1.2775 1.442 1.43225 1.3785 1.42275 1.36975

Table C.9. continued

q Cf(DOPO )2(NO3)(py). MOS ESD

1 and 2 average -1.2052179 0.17934675

3 and 4 average -1.2261872 0.14978911 overall average -1.2157026 0.16093046

q sq Synthesis of Np(DOPO )3(DOPO ). In a 20 mL scintillation vial, NpCl4(DME)2 (0.010g, mmol) was weighed out and dissolved in 1 mL of thf. Three equivalents of HDOPOq (g, mmol) was added to the solution containing the Np. One equivalence of KC8 was added slowly turning the blue solution to green. The solution was filtered, and the solvent was removed. The product was extracted with pentane and transferred to a new vial. The pentane was remove, and the residue was dissolved in 2 mL of pyridine. The solution sat overnight producing green block crystals suitable for X-ray diffraction.

q sq 239 Synthesis of Pu(DOPO )3(DOPO ). A 7 ml scintillation vial was charged with PuBr3 (0.005 g, 0.0104 mmol) and 2 ml of pyridine. A solution of HDOPOq (0.0135 g, 0.0311 mmol) dissolved in 2 mL of pyridine was added to the vial, causing a color change from yellow to dark purple. The solution sat overnight to allow evaporation of solvent. Dark purple block crystals suitable for X-ray analysis formed, and were analyzed immediately

Figure C.1. Schematic of the synthesis of Np and Pu DOPO.

1.8

1.6 Nd(DOPO)3

1.4 Np(DOPO)3

Pu(DOPO)3 1.2

0.8

Absorbance Absorbance (a.u.) 0.6

0.4

0.2

0 320 420 520 620 720 820 920 Wavelength (nm) q Figure C.2. Solid state UV-Vis-NIR of Np and Pu DOPO complexes compared to Nd(DOPO )3.

Table C.10. Crystallographic table of Np and Pu DOPO compounds.

Compound q sq q sq Np(DOPO )3(DOPO ) Pu(DOPO )3(DOPO ) Formula Mass 1709.03 1711.99 Color and habit Green, Plate Purple, block

Space group P21/c P21/c a (Å) 14.596(3) 14.9354(8) b (Å) 15.571(3) 15.5118(8) c (Å) 38.085(7) 37.7368 (19) α(°) 90 90 β (°) 91.074(3) 90.9134 (12) γ (°) 90 90 3 V (Å ) 8655(3) 8741.6(8) Z 4 4

T (K) 130(2) 130(2)

λ (Å) 0.71073 0.71073

Maximum 2θ (°) 56.564 55.000

3 ρcalc (g/cm ) 1.199 1.301 μ (Mo Kα) (cm–1) 5.59 8.12

2 2 a R(F) for Fo > 2σ(Fo ) 0.0564 0.0314

2 b Rw(Fo ) 0.0950 0.0672

Table C.11. Selected bond lengths for Np and Pu DOPO compounds. (Å)

q sq q sq Np(DOPO )3(DOPO ) Pu(DOPO )3(DOPO ) M-O1 2.309(6) 2.2886(17) M-O3 2.285(5) 2.2886(18) M-O4 2.360(6) 2.3436(18) M-O6 2.424(5) 2.4001(17) M-O7 2.397(5) 2.3867(17) M-O9 2.426(5) 24253(17) M-N1 2.409(7) 2.412(2) M-N2 2.555(7) 2.538(2) M-N3 2.563(7) 2.542(4)

q sq Table C.12. Metrical oxidation states table of Np(DOPO )2(DOPO ).

Np(DOPOq)3( DOPOsq). C1-N C2-O C1-C2 C2-C3 C3-C4 C4-C5 C5-C6

1.337 1.273 1.439 1.423 1.39 1.442 1.369

1.303 1.269 1.436 1.422 1.375 1.446 1.37

1.343 1.317 1.417 1.416 1.389 1.418 1.398

1.34 1.308 1.41 1.418 1.389 1.429 1.39

1.336 1.271 1.439 1.43 1.368 1.434 1.371

1.308 1.278 1.433 1.43 1.369 1.438 1.379

1 and 2 average 1.32 1.271 1.4375 1.4225 1.3825 1.444 1.3695

3 and 4 average 1.3415 1.3125 1.4135 1.417 1.389 1.4235 1.394

5 and 6 average 1.322 1.2745 1.436 1.43 1.3685 1.436 1.375

overall average 1.3278333 1.286 1.429 1.4231666 1.38 1.4345 1.3795

Pu(DOPOq)3(DOPOsq). MOS ESD

1 and 2 average -1.1302898 0.22614746

3 and 4 average -1.9525737 0.22834663

overall average -1.162061 0.19536736

q sq Table C.13. Metrical oxidation states table of Pu(DOPO )3(DOPO ).

Pu(DOPOq)3(D OPOsq). C1-N C2-O C1-C2 C2-C3 C3-C4 C4-C5 C5-C6

1.345 1.316 1.423 1.404 1.392 1.416 1.384

1.346 1.324 1.423 1.398 1.392 1.411 1.383

1.331 1.286 1.439 1.416 1.381 1.422 1.372

1.316 1.272 1.454 1.424 1.37 1.435 1.37

1.321 1.268 1.445 1.423 1.376 1.43 1.37

1.332 1.273 1.438 1.427 1.378 1.424 1.374

1 and 2 average 1.3455 1.32 1.423 1.401 1.392 1.4135 1.3835

3 and 4 average 1.3235 1.279 1.4465 1.42 1.3755 1.4285 1.371

5 and 6 average 1.3265 1.2705 1.4415 1.425 1.377 1.427 1.372 overall average 1.3318333 1.2898 1.437 1.4153333 1.3815 1.423 1.3755

Pu(DOPOq)3(DOPOsq). MOS ESD

1 and 2 average -2.062786279 0.179310618

3 and 4 average -1.225090986 0.175771243 overall average -1.213749739 0.181104242

243 Am(t1/2=7380 years) represent serious health risks due to their a emission as the radiotoxicity associated with its , , and emitting daughters. All studies with these actinides were conducted in a laboratory dedicated to studies on transuranium elements. This laboratory is in a nuclear science facility and is equipped with HEPA-filtered hoods and gloveboxes. A series of instruments continually monitor the radiation levels in the laboratory. All free-following actinide solids are handled in gloveboxes, and the products are only examined when coated with immersion or krytox oil. There are significant limitations in accurately determining yields of these actinide compounds because it requires to drying, isolating, and weighing a solid, which

possess an inhalation hazard and manipulation difficulties given the small quantities of product from these reactions. Anhydrous THF and pentane were dried and stored over sodium. Trimethylsilanebromide was purchased from Sigma-Aldrich without further purification.

Single crystals of each compound were mounted on a Mitogen mounts with krytox oil and the crystals were optically aligned on a Bruker D8 Quest X-ray Diffractometer using a built-in camera. Preliminary measurements were performed using an Imus X-ray source (Mo Ka, = 0.71073 A) with high-brillance and high-performance focusing quest multilayer optics. APEXIII software was used for solving the unit cells and data collection. The reflection’s intensities of a sphere were collected by a mixture of four sets of frames. Each set had a different omega angle for the crystal, and each exposure covered a range of 0.50 in , totaling to 1464 frames. The frames were collected with an exposure time of 30 seconds on the crystal. SAINT software was used for data integraphic including polarization and Lorentz corrections. PLATON was used to finalize the structure for any issues. CIFs are available from the Cambridge Crystallographic Data Centre (CCDC) and are given in the Supporting Information.

UV-Vis-Near-IR (NIR) Spectroscopy: UV-Vis- NIR data were collected for each compound using a Craic Technologies microspectrophotometer. Single crystals of each compound were paced on a quartz slide in immersion oil, and the data was collected from 300 nm to 1100 nm.

A 20 mL scintillation vial was charged with AmO2 (x.xx mg, x.x mmol) and dissolved in 300 l of concentrated HBr. The solution was heated to dryness. The process was repeated two more times. The yellow residue was transferred into the glovebox antechamber and pumped under vacuum for 3 hours before transferring into the glovebox. The vial was brought into the glove box and 0.5 ml of TMSBr was added to the yellow residue and stirred for 30 minutes. The TMSBr was removed, and the residue was dissolved in 1 ml of THF resulting in a yellow solution. The solution was layered with pentane to produce suitable peach crystals for X-ray diffraction.

Figure C.3. 7-coordinate Am center of AmBr3(thf)4.

1.4

1.2

0.8

0.6

Absorbance Absorbance (a.u.) 0.4

0.2

0 350 450 550 650 750 850 950 1050 Wavelength (nm)

Figure C.4. Solid state UV-Vis-NIR spectrum of AmBr3(thf)4.

Table C.14. Crystallographic information of AmBr3(thf)4.

Compound AmBr3(thf)4

Formula Mass 771.14

Color and habit Peach, Block

Space group P-1 a (Å) 8.2085 (5) b (Å) 9.3333(5) c (Å) 15.3833 (12)

α(°) 78.9492(12)

β (°) 86.9269(13)

γ (°) 74.9655(12)

V (Å3) 1117.10(11)

Z 2

T (K) 129 (2)

λ (Å) 0.71

Maximum 2θ (°) 55.15

3 ρcalc (g/cm ) 2.293

μ (Mo Kα) (cm–1) 88.15

2 2 a R(F) for Fo > 2σ(Fo ) 0.0308

2 b Rw(Fo ) 0.0603

Table C.15. Selected bond lengths for AmBr3(thf)4. (Å)

Am-O1 2.466 (4) Am-Br1 2.8222 (6) Am-O2 2.493 (4) Am-Br2 2.8445 (6) Am-O3 2.533 (4) Am-Br3 2.8610 (6) Am-O4 2.467 (4)

APPENDIX D TABLES FROM CHAPTER 5

Table D.1. Crystallographic table of [Th(O2)(terpy)(NO3)2]3.

Compound [Th(O2)(terpy)(NO3)2]3

Formula Mass 1987.14

Color and habit Colorless, rhombic Space group P-1 a (Å) 13.2177(12) b (Å) 13.9068(13) c (Å) 18.4265(17) α(°) 86.9880(15)

β (°) 88.0749(15)

γ (°) 83.8940(16)

V (Å3) 3361.9(5)

Z 2 T (K) 100 (2)

λ (Å) 0.71073

Maximum 2θ (°) 56.222

3 ρcalc (g/cm ) 1.963

μ (Mo Kα) (cm–1) 67.07

2 2 a R(F) for Fo > 2σ(Fo ) 0.0313

2 b Rw(Fo ) 0.0987

Table D.2. Selected bond lengths for [Th(O2)(terpy)(NO3)2]3. (Å)

Th-Terpy Th-Nitrate Th-Peroxide Th(1)-N(1) 2.693(5) Th(1)-O(2) 2.551(4) Th(1)-O(19) 2.332(4) Th(1)-N(2) 2.717(4) Th(1)-O(3) 2.664(4) Th(1)-O(20) 2.387(4) Th(1)-N(3) 2.711(4) Th(1)-O(5) 2.598(4) Th(1)-O(23) 2.367(4) Th(2)-N(4) 2.671(5) Th(1)-O(6) 2.596(4) Th(1)-O(24) 2.408(4) Th(2)-N(5) 2.701(4) Th(2)-O(8) 2.566(4) Th(2)-O(21) 2.339(4) Th(2)-N(6) 2.742(5) Th(2)-O(9) 2.742(4) Th(2)-O(22) 2.406(4) Th(3)-N(7) 2.642(5) Th(2)-O(10) 2.642(4) Th(2)-O(23) 2.353(4) Th(3)-N(8) 2.681(5) Th(2)-O(11) 2.647(4) Th(2)-O(24) 2.366(4) Th(3)-N(9) 2.668(5) Th(3)-O(14) 2.581(4) Th(3)-O(19) 2.366(4) Th(3)-O(15) 2.633(4) Th(3)-O(20) 2.371(4) Th(3)-O(17) 2.609(4) Th(3)-O(21) 2.337(4) Th(3)-O(18) 2.599(4) Th(3)-O(22) 2.398(4)

Table D.3. Peroxide bond lengths. (Å)

O(19)-O(20) 1.518(5) O(21)-O(22) 1.518(5) O(23)-O(24) 1.513(5)

Table D.3. Selected bond angles for Th-peroxide-Th. (o)

Th(1)-O(19)-Th(3) 125.94(17) Th(1)-O(20)-Th(3) 123.18(15) Th(1)-O(23)-Th(2) 131.50(17) Th(1)-O(24)-Th(2) 128.76(16) Th(2)-O(21)-Th(3) 127.96(17) Th(2)-O(22)-Th(3) 122.02(16)

APPENDIX E TABLES FROM CHAPTER 6 Table E.1. Crystallographic information for CsM(CrO4)2.

Compound -CsAm(CrO4)2 -CsAm(CrO4)2 CsNd(CrO4)2 CsSm(CrO4)2

Formula Mass 607.91 607.91 509.15 515.26

Color and habit Dark Red Block Dark Red, Block Green, rod Orange, Prism

Space group P-1 P2/c P2/c P2/c a (Å) 5.8341 (14) 9.1759(11) 9.244 (2) 9.1977 (12) b (Å) 7.2548 (17) 5.5211 (6) 5.5676 (14) 5.5221 (7) c (Å) 9.786 (2) 7.7323 (9) 7.795 (2) 7.7074 (10)

α(°) 73.026 (4) 90 90 90

β (°) 88.581 (5) 98.691 (2) 98.785 (6) 98.818 (3)

γ (°) 81.081 (5) 90 90 90

V (Å3) 391.28 (16) 387.23 (8) 396.51 (18) 386.84 (9)

Z 2 2 2 2

T (K) 131 137 298 298

λ (Å) 0.71073 0.71073 0.71073 0.71073

Maximum 2θ (°) 30.501 27.529 27.502 27.505

3 ρcalc (g/cm ) 5.160 5.214 4.265 4.424

μ (Mo Kα) (cm–1) 170.21 171.99 136.69 148.90

2 R(F) for Fo > 0.0185 0.0203 0.0139 2 a 2σ(Fo ) 0.0218

2 b Rw(Fo ) 0.0456 0.0459 0.0567 0.0352

Table E.2. Crystallographic Information for Cs2M2(CrO4)4

Compound Cs2La2(CrO4)4 Cs2Pr2(CrO4)4

Formula Mass 1007.64 1011.64

Color and habit Yellow, Prism Yellow, Prism

Space group P21/c P21/c a (Å) 9.3329(10) 9.324(4) b (Å) 7.5558(8) 7.500(3) c (Å) 11.2150(12) 11.134(5)

α(°) 90 90

β (°) 91.600 (2) 91.235 (9)

γ (°) 90 90

3 V (Å ) 790.55 (15) 778.5(6) Z 2 2 T (K) 298 298 λ (Å) 0.71073 0.71073

Maximum 2θ (°) 27.531 27.579

3 ρcalc (g/cm ) 4.233 4.316

μ (Mo Kα) (cm–1) 125.48 135.14

2 2 a R(F) for Fo > 2σ(Fo ) 0.0269 0.0261

2 b Rw(Fo ) 0.0962 0.0708

RF   Fo  Fc  Fo 1 2 2 2   2 2  4  Rw Fo   w Fo  Fc  wFo        

Table E.3. Selected Bond Distances (Å) for CsLn(CrO4)2 and CsAm(CrO4)2

CsLa(CrO4)2 CsPr(CrO4)2 La(1)-O(1) 2.501 (4) Cr(1)-O(1) 1.635 (4) Pr(1)-O(2) 2.530 (3) Cr(1)-O(1) 1.599 (3) La(1)-O(2) 2.554 (3) Cr(1)-O(2) 1.678 (3) Pr(1)-O(3) 2.489 (3) Cr(1)-O(2) 1.648 (3) La(1)-O(2) 2.565 (3) Cr(1)-O(3) 1.608 (4) Pr(1)-O(3) 2.558 (3) Cr(1)-O(3) 1.678 (3) La(1)-O(4) 2.589 (3) Cr(1)-O(4) 1.673 (3) Pr(1)-O(4) 2.422 (3) Cr(1)-O(4) 1.661 (3) La(1)-O(5) 2.530 (3) Cr(2)-O(5) 1.678 (3) Pr(1)-O(5) 2.463 (3) Cr(2)-O(5) 1.634 (3) La(1)-O(5) 2.573 (3) Cr(2)-O(6) 1.596 (4) Pr(1)-O(7) 2.512 (3) Cr(2)-O(6) 1.605 (3) La(1)-O(7) 2.579 (4) Cr(2)-O(7) 1.640 (3) Pr(1)-O(7) 2.540 (3) Cr(2)-O(7) 1.682 (3) La(1)-O(8) 2.474 (4) Cr(2)-O(8) 1.656 (4) Pr(1)-O(8) 2.552 (3) Cr(2)-O(8) 1.670 (3) Average 2.555 (4) Average 1.646 (4) Average 2.531 (3) Average 1.647 (3) La-O Cr-O Pr-O Cr-O

CsNd(CrO4)2 CsSm(CrO4)2 Nd(1)-O(1) 2.381 (2) Cr(1)-O(1) 1.650 (2) Sm(1)-O(1) 2.343 (2) Cr(1)-O(1) 1.650 (2) Nd(1)-O(3) 2.425 (2) Cr(1)-O(2) 1.616 (2) Sm(1)-O(3) 2.389 (2) Cr(1)-O(2) 1.609 (2) Nd(1)-O(4) 2.573 (2) Cr(1)-O(3) 1.692 (2) Sm(1)-O(4) 2.546 (2) Cr(1)-O(3) 1.692 (2) Average 2.460 (2) Cr(1)-O(4) 1.639 (2) Average 2.426 (2) Cr(1)-O(4) 1.639 (2) Nd---O Sm-O Average 1.649 (2) Average 1.648 (2) Cr---O Cr-O

-CsAm(CrO4)2 -CsAm(CrO4)2 Am(1)-O(1) 2.441 (3) Cr(1)-O(1) 1.699 (3) Am(1)-O(2) 2.354 (4) Cr(1)-O(1) 1.609 (4) Am(1)-O(1) 2.466 (3) Cr(1)-O(2) 1.633 (4) Am(1)-O(3) 2.408 (4) Cr(1)-O(2) 1.690 (4) Am(1)-O(2) 2.449 (3) Cr(1)-O(3) 1.598 (3) Am(1)-O(4) 2.554 (4) Cr(1)-O(3) 1.650 (4) Am(1)-O(4) 2.430 (3) Cr(1)-O(4) 1.676 (3) Cr(1)-O(4) 1.640 (4) Am(1)-O(4) 2.635 (3) Cr(2)-O(5) 1.647 (4) Average 2.439(4) Average 1.647 (4) Am-O Cr-O Am(1)-O(5) 2.425 (4) Cr(2)-O(6) 1.662 (4) Am(1)-O(6) 2.332 (4) Cr(2)-O(7) 1.594 (4) Am(1)-O(8) 2.324 (4) Cr(2)-O(8) 1.640 (4) Average 2.438(4) Average 1.644(4) Am-O Cr-O

MO number energy (eV) Mulliken contributions (%)

Am f O p

266 -3.585 59 O24 9 O16 6 O28 4 O12 4 O34 3 O22 3 O25 2

265 -3.661 76 O25 3 O28 3

264 -3.722 75 O28 4 O25 4 O10 2

263 -3.772 28 O28 15 O24 14 O34 10 O16 7 O20 4 O12 4 O31 3 O22 3

262 -3.955 39 O12 14 O24 11 O20 9 O34 6 O16 5 O26 3 O28 3

261 -3.996 63 O28 8 O34 5 O31 2 O24 2 O22 2

260 -4.124 69 O25 8 O34 3 O31 3 O12 2

259 -4.174 9 O22 22 O28 17 O25 17 O14 11 O34 6 O18 5 O31 3

258 -4.269 20 O12 19 O20 13 O16 10 O28 9 O26 5 O31 3 O22 3 O25 2 O29 2

257 -4.322 15 O22 16 O28 13 O12 10 O14 10 O18 9 O24 5 O34 4 O16 4 O25 3

256 -4.421 31 O28 16 O12 11 O16 7 O31 7 O24 6 O14 3 O34 3

255 -4.604 12 O16 20 O24 13 O12 9 O20 9 O28 7 O31 6 O25 5 O36 3 O27 2 O22 2

Table E.4. continued

254 -4.639 4 O36 22 O27 13 O14 13 O18 9 O34 7 O33 6 O28 4 O10 3 O24 3 O25 2

253 -4.687 4 O14 25 O10 16 O18 12 O27 10 O36 8 O34 4 O31 3 O24 3 O22 2 O25 2

252 -4.767 5 O34 14 O24 13 O36 12 O27 12 O33 7 O16 5 O20 4 O22 4 O18 3 O31 3 O12 3 O28 3 O25 2

251 -4.861 8 O22 25 O10 14 O18 14 O14 12 O36 3 O34 3 O11 2 O27 2 O12 2

250 -4.990 5 O36 37 O30 18 O33 13 O27 13 O14 2

249 -5.093 6 O12 20 O25 14 O16 11 O28 7 O34 6 O31 5 O26 4 O20 4 O24 3

248 -5.143 4 O11 18 O27 18 O23 17 O33 10 O30 4 O36 4 O19 4 O18 3 O10 3

247 -5.203 3 O27 18 O23 15 O11 14 O33 9 O30 7 O25 5 O36 4 O28 3 O34 3

Table E.5. QTAIM Am–O BCP parameters (au) and delocalization indices for Am(CrO4)7Cs11.

 2 H (Am,O)

Am–O13 0.051 0.216 0.003 0.255

Am–O25 0.054 0.224 0.004 0.289

Am–O10 0.054 0.212 0.004 0.331

Am–O35 0.068 0.290 0.008 0.348

Am–O11 0.048 0.204 0.002 0.268

Am–O24 0.053 0.220 0.003 0.303

Am–O30 0.067 0.282 0.008 0.370

Am–O22 0.035 0.137 0.000 0.209

Table E.6. Parameters of the Am-5f reduced density matrix computed employing LDA+GA assuming U=6 and J=0.7, see Eq. 1. Largest probability weights 푤푖, corresponding quantum labels 푁푖 (number of electrons) and 퐽푖 (total angular momentum).

푖 1 2 3 4

푤푖 0.88 0.06 0.04 0.002

푁푖 6 7 5 6

Ji 0 3.5 2.5 6

REFERENCES 1. Kaltsoyannis, N. Does covalency increase or decrease across the actinide series? Implications for minor actinide partitioning. Inorg. Chem. 2012, 52, 3407-3413. 2. Gorden, A. E. V.; DeVore, M. A., II; Maynars, B. A. Coordination chemistry with f-element complexes for an improved undersanding of factors that contribute to extraction selectivity. Inorg. Chem. 2013, 52, 3445-3458.

3. Birkett, J. E.; Carrott, M. J.; Fox, O. D.; Jones, C. J.; Maher, C. J.; Roube, C. V.; Taylor, R. J.; Woodhead, D. A. Recent developments in the PUrex process for nuclear fuel reprocessing: Complexant based stripping for uranium/plutonium separation. Chimia, 2005, 59, 898-904.

4. Taylor, R. J.; Gregson, C. R.; Carrott, M. J.; Mason, C.; Sarsfield, M. J. Neptunium extraction and stability in the GANEX solvent: 0.2 M TODGA/0.5 M DMDOHEMA/kerosene. Solvent Extraction and Ion Exchange. 2013, 31, 422-462.

5. Shannon, R. D. & Prewitt, C. T. Effective ionic radii in oxides and fluorides. Acta Crystallogr. 1969, B25, 925 946.

6. Shannon, R. D. Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallogr. 1976, A32, 751-767.

7. Neidig, M. L.; Clark, D. L.; Martin, R. L. Covalency in f-element complexes. Coord. Chem. Rev. 2013, 257, 394-406.

8. Clark, D.L. The chemical complexities of plutonium. Los Alamos Science. 2000, 26, 364- 381.

9. Fox, A. R.; Bart, S. C.; Meyer, K; Cummins, C. C. Towards uranium catalysts. Nature, 2008, 455, 341-349.

10. Lukens, W. W.; Edelstein, N. M.; Magnani, N.; Hayton, T. W.; Fortier, S.; Seaman, L. A. Quantifying the  and  interactions between U(V) f orbitals and halide, alkyl, alkoxide, amide and ketamide ligands. J. Am. Chem. Soc. 2013, 135, 10742−10754.

11. Hubbard, J.; Rimmer, D. E.; Hopgood, F. R. A. Weak covalency in trasition metal salts Proc. Phys. Soc., London 1966, 88, 13−36.

12. Barros, N.; Maynau, D.; Maron, L.; Eisenstein, O.; Zi, G.; Andersen, R. A. Single but stronger UO, double but weaker UNME bonds: the tale told by Cp2UO and Cp2UNR. Organometallics 2007, 26, 5059−5065.

13. Prodan, I. D.; Scuseria, G. E.; Martin, R. L. Covalency in the actinide dioxides: Systematic study of the electronic properties using screened hybrid density functional theory. Phys. Rev. B, 2007, 76.

14. Minasian, S. G.; Keith, J. M.; Batista, E. R.; Boland, K. S.; Clark, D. L.; Conradson, S. D.; Kozimor, S. A.; Martin, R. L.; Schwarz, D. E.; Shuh, D. K.; Wagner, G. L.; Wilkerson, M. P.; Wolfsberg, L. E.; Yang, P. Determining relative f and d orbital contributions to M-CL 2- - covalency in MCl6 (M= Ti, Zr, Hf, U) and UOCl5 Using Cl K-Edge X-ray Absorption Spectroscopy and Time Dependent Density Functional Theory.J. Am. Chem. Soc. 2012, 134, 5586−97.

15. Loble, M. W.; Keith, J. M.; Altman, A. B.; Stieber, S. C. E.; Batista, E. R., Boland, K. S.; Conradson, S. D.; Clark, D. L.; Pacheco, J. L.; Kozimor, S. A.; Martin, R. L.; Minasian, S.G.; Olson, A. C.; Scott, B. L.; Shuh, D. K.; Tyliszczak, T.; Wilkerson, M. P., Zehnder, R. A. Covalency in lanthanides. An X-ray Absorption Spectroscopy and Density Functional X- Theory Study of LnCl6 (x= 3,2). J. Am. Chem. Soc. 2015,137, 2506-2523.

16. Jones, M. B.; Gaunt, A. J., Recent Developments in Synthesis and Structural Chemistry of Nonaqueous Actinide Complexes. Chem. Rev. 2012, 113, 1137-1198.

17. Avens, L. R., Bott, S. G., Clark, D. L., Sattelberger, A. P., Watkin, J. G., and Zwick, B. D., A Convenient Entry into Trivalent Actinide Chemistry: Synthesis and Characterization of AnI3(THF)4 and An[N(SiMe3)2]. Inorg. Chem., 1994,33, 2248-2256.

18. Clark, D. L.; Frankcom, T. M.; Miller, M. M.; and Watkin, J. G.; Facile solution routes to hydrocarbon-solule lewis base adducts of thorium tetrahalides. Synthesis, characterization, and x-ray structure of ThBr4(THF)4. Inorg. Chem. 1992, 31,1628-1633.

19. Cantat, T.; Scott, B. L.; Kiplinger, J. L.; Convenient access to the anhydrous thorium tetrachloride Complexes ThCl4(DME)2, ThCl4(1,4-dioxane)2 and ThCl4(THF)3.5 using commercially available and inexpensive Starting materials. Chem. Commun., 2010,46, 919- 921

20. Minasian, S. G., Boland, K. S., Fellers, R. K., Gaunt, A. J., Kozimor, S. A.; May, I.; Reilly, S. D.; Scott, B. L.; and Shuh, D. K. Synthesis and Structure of(Ph4P)2MCl6. Inorg. Chem. 2012, 51,5728-5736.

21. Cross, J. N.; Su, J.; Batista, E. R.; Cary, S. K.; Evans, W. J.; Kozimor, S. A.; Mocko, V.; Scott, B. L.; Stein, B. W.; Windorff, C. J.; and Yang, P. Covalency in Americium(III) Hexachloride. J. Am. Chem. Soc. 2017, 139, 8667-8677.

22. Reilly, S. D.; Brown, J. L.; Scott, B. L.; and Gaunt, A. J. Synthesis and Characterization of NpCl4(DME)2 and PuCl4(DME)2 Neutral Transuranic An(IV) starting materials. Dalton Trans., 2014,43,1498-1501.

23. Gaunt, A. J.; Enriquez, A. E.; Reilly, S. D.; Scott, B. L.; and Neu, M. P. Structural characterization of Pu[N(SiMe3)2]3, a synthetically useful nonaqueous plutonium (iii) precursor. Inorg. Chem., 2008, 47, 26-28.

24. Jones, M. B.; Gaunt, A. J.; Gordon, J. C.; Kaltsoyannis, N.; Neu, M. P.; Scott, B. L. Uncovering f-element bonding differences and electronic structure in a series of 1: 3 and 1: 4 complexes with a diselenophosphinate ligand. Chem. Sci. 2013, 4, 1189-1203.

25. Gaunt, A. J.; Reilly, S. D.; Enriquez, A. E.; Hayton, T. W.; Boncella, J. M.; Scott, B. L.; and Neu, M. P. Low-valent molecular plutonium halide complexes. Inorg. Chem., 2008, 47, 8412

26. Laubereau, P. G.; Burns, J. H., Microchemical Preparation of Tricyclopentadienyl Compounds of Berkelium, Californium, and Some Lanthanide Elements. Inorg. Chem. 1970, 9, 1091- 1095.

27. Silver, M. A.; Cary, S. K., Johnson, J. A., Baumbach, R. E.; Arico, A. A.; Luckey, M.; Urban, M.; Wang, J. C.; Polinski, M. J., Chemey, A., Liu, G.; Chen, K.; Van Cleve, S. M.; Marsh, M. L.; Meaton, T. M.; Van de Burgt, L.J.; Gray, A. L.; Hobart, D. E.; Hanson, K.; Maron, L.; Gendron, F.; Autschabach, J.;, Speldrich, M.; Kogerler, P.; Yang, P.; Braley, J.; Albrecht-Schmitt, T. E. Characterization of Berkelium(III) dipicolinate and borate compounds in solution and the solid state. Science, 2016, 353.

28. Cary, S. K.; Vasiliu, M.; Baumbach, R. E.; Stritzinger, J. T.; Green, T. D.; Diefenbach, K.; Cross, J. N.; Knappenberger, K. L.; Liu, G.; Silver, M. A. Emergence of californium as the second transitional element in the actinide series. Nat. Commun. 2015, 6, 6827.

29. Polinski, M. J.; Wang, S.; Alekseev, E. V.; Depmeier, W.; Albrecht‐Schmitt, T. E. Bonding changes in plutonium(III) and americium(III) borates. Angew. Chem. Int. Ed. 2011, 50, 8891- 8894.

30. Polinski, M. J.; Garner III, E. B.; Maurice, R.; Planas, N.; Stritzinger, J. T.; Parker, T. G.; Green, T. D.; Alekseev, E. V.; Van Cleve, S. M.; Depmeier, W.; L. Gagliardi, L.; Shatruk, M.; Knappenberger, K. L.; Liu, G.; Skanthakumar, S.; Soderholm, L.; Dixon, D. A.; Albrecht-Schmitt, T. E. Unusual structure, bonding and properties in a californium borate. Nat. Chem. 2014, 6, 387-392.

31. Kolarik, Z. Complexation and separation of lanthanides(iii) and actinides(iii) by heterocyclic n-donors in solutions. Chem. Rev. 2008, 108, 4208-4252.

32. Jensen, M. P.; Bond, A. H. J. Am. Chem. Soc., 2002, 124, 9870.

33. Jensen, M. P.; Bond, A. H. Radiochim. Acta, 2002, 90, 205

34. Guillaumont, D. J. Phys. Chem. A, 2004, 108, 6893

100

35. Iveson, P. B.; Riviere, C.; Guillaneux, D.; Nierlich, M.; Thuery,P.; Ephritikine, M.; Madic, C. Chem. Commun. 2001, 1512.

36. Lewis, F. W.; Harwood, L. M.; Hudson, M. J.; Drew, M. G. B.; Modolo, G.; Syupla, M.; Desreux, J. F.; Bouslimani, N.; Vidick, G. Interaction of 6,6′′-bis(5,5,8,8-tetramethyl-5,6,7,8- tetrahydro-1,2,4-benzotriazin-3-yl)-2,2′:6′,2′′-terpyridine (CyMe4-BTTP) with some trivalent ions such as lanthanide(III) ions and americium(III). Dalton Trans. 2010, 39, 5172-5182.

37. Y. Zhu, J. Chen and R. Jiao, Extraction of Am(III) and Eu(III) from nitrate solution with purified Cyanex 301. Solvent Extr. Ion Exch., 1996, 14, 61.

38. J. R. Klaehn, D. R. Peterman, M. K. Harrup, R. D. Tillotson, T. A. Luther, J. D. Law and L. M. Daniels, Synthesis of symmetric dithiophosphinic acids for “minor actinide” extraction. Inorg. Chim. Acta, 2008, 361, 2522-2532.

39. D. R. Peterman, M. R. Greenhalgh, R. D. Tillotson, J. R. Klaehn, M. K. Harrup, T. A. Luther and J. D. Law, Selective extraction of minor actinides from acidic media using symmetric and asymmetric dithiophosphinic acids. Sep. Sci. Technol., 2010, 45, 1711-1717.

40. Macor, J. A.; Brown, J. L.; Cross, J. N.; Daly, S. R.; Gaunt, A. J.; Girolami, G. S.; Janicke, M. T.; Kozimor, S. A.; Neu, M. P.; Olson, A. C.; Reilly, S. D.; Scott, B. L. Coordination chemisty of 2,2’-biphenylenedithiophosphinate and diphenyldithiophosphinate with U, Np, and Pu. Dalton Trans., 2015, 44, 18923-18936

41. Gaunt, A. J.; Reilly, S. D.; Enriquez, A. E.; Scott, B. L.; Ibers, J. A.; Sekar, P.; Ingram, K. I.; Kaltsoyannis, N.; Neu, M. P. Experimental and Theoretical Comparison of Actinide and Lanthanide Bonding in M [N (EPR2)2]3 Complexes (M= U, Pu, La, Ce; E= S, Se, Te; R= Ph, iPr, H). Inorg. Chem. 2008, 47, 29-41.

42. Anderson, N. H.; Odoh, S. O.; Yao, Y.; Williams, U. J.; Schaefer, B. A.; Kiernick, J.J.; Lewis, A. J.; Gosher, M. D.; Fanwick, P. E.; Schelter, E. J.; Walensky, J. R.; Gagliadi, L.; Bart, S. C. Harnessing redox activity for the formation of uranium tris(imido)compounds. Nature Chemistry 2014, 6, 919-926.

43. Anderson, N. H.; Xie, J.; Ray, D.; Zeller, M. Gagliardi, L.; and Bart S. C. Elucidating bonding preference in tetrakis(imido)urinate(vi) dianions. Nature Chemistry, 2017, 9, 850- 855.

44. Brown, J. L.; Batista, E. R.; Boncella, J. M.; Gaunt, A. J.; Reilly, S. D.; Scott, B. L.; and Tomson N. C. A linear trans-Bis(imido)Neptunium(V) Actynly Analog: V t Np (NDIPP)2( Bu2bipy)2Cl. J. Am. Chem. Soc. 2015, 137, 9583-9586.

45. Brown, J. L.; Gaunt, A. J.; King, D. M.; Liddle, S.T.; Reilly, S. D.; Scott, B. L.; and Wooles, A. J. Neptunium and plutonium complexes with a sterically encumbered triamidoamine(TREN) scaffold. Chem. Commun, 2016, 52, 5428-5431.

101

46. Windorff, C. J.; Chen, G. P.; Cross, J. N.; Evans, W. J.; Furche, F.; Gaunt, A. J.; Janicke, M. T.; Kozimor, S. A.; and Scott, B. L. Idenification of the Formal +2 Oxidation state of Plutonium; Synthesis and Characterization of [PuII[C5H3(SiMe3)2]3}- J. Am. Chem. Soc. 2017, 139, 3970-3973.

47. Dutkiewicz, Apostolidis, C.; Walter, O.; and Arnold, P. L. Reduction chemistry of neptunium cyclopentadienide complexes: from structure to understanding. Chem. Sci. 2017, 8 2553- 2561.

48. Dutkiewicz, M. S.; Farnaby, J. H.; Apostolidis, C.; Colineau, E.; Walter, O.; Magnani, N.; Gardiner, M. G.; Love, J. B.; Kaltsoyannis, N.; Caciuffo, R. Organometallic neptunium(III) complexes. Nat. Chem. 2016, 8, 797-802.

49. Berthet, J. C.; Miquel, Y.; Iveson, P. B.; Nierlich, M.; Thuery, P.; Madic, C.; and Ephritikhine, M. The affinity and selectivity of terdentate nitrogen ligands towards trivalent lanthanide and uranium ion viewed from the crystal structures of the 1:3 complexes. J. Chem. Soc., Dalton Trans., 2002, 3265-3272.

50. Giese, M.; Albrecht, M.; and Rissanen, K. Experimental investigation of anion-pi interactions- applications and biochemical relevance. Chem. Commun. 2016, 52, 1778-1795.

51. Roos, B. O., Taylor, P. R., & Si, P. E. A complete active space SCF method (CASSCF) using a density matrix formulated super-CI approach. Chemical Physics, 1980, 48, 157-173.

52. Malmqvist, P. Å., & Roos, B. O. The CASSCF state interaction method. Chemical physics letters, 1989, 155, 189-194.

53. Angeli, C., Cimiraglia, R., Evangelisti, S., Leininger, T., & Malrieu, J. P. Introduction of n- electron valence states for multireference perturbation theory. The Journal of Chemical Physics, 2001, 114, 10252-10264.

54. Neese, F. The ORCA program system. Wiley Interdisciplinary Reviews: Computational Molecular Science, 2012, 2, 73-78.

55. Pantazis, D. A., & Neese, F. All-electron scalar relativistic basis sets for the actinides. Journal of Chemical Theory and Computation, 2011,7(3), 677-684.

56. Fryier-Kanssen, I., Austin, J., Kerridge, A. Topological Study of Bonding in Aquo and Bis(triazinyl)pyridine Complexes of Trivalent Lanthanides and Actinides: Does Covalency Imply Stability? Inorg. Chem., 2016, 55, 10034-10042. 57. Charushnikova, I. A.; Fedoseev, A. M.; Perminov, V. P. Synthesis and structure of complex nitrates of some ln(iii) and of am(iii) with 1,10-phenanthroline-2,9-dicarboxylic acid anions. Radiochemistry (Moscow, Russ. Fed.), 2015, 57, 111-121. 102

58. Liu, G.; Cary, S. K.; Albrecht-Schmitt, T. E. Metastable charge-transfer state of californium(iii) compounds. Physical Chemistry Chemical Physics, 2015, 17, 16151-16157.

59. Ivakhnenko, E. P. et al. Synthesis, molecular and electronic structures of six-coordinate transition metal (mn, fe, co, ni, cu, and zn) complexes with redox-active 9- hydroxyphenoxazin-1-one ligands. Inorg. Chem., 2011, 50, 7022-7032.

60. Ranis, L. G.; Werellapatha, K.; Pietrini, N. J.; Bunker, B. A.; Brown, S. N. Metal and ligand effects on bonding in group 6 complexes of redox-active amidodiphenoxides. Inorg. Chem., 2014, 53, 10203-10216.

61. Pattenaude, S. A. et al. Spectroscopic and structural elucidation of uranium dioxophenoxazine complexes. Inorg. Chem., 2015, 54, 6520-6527.

62. Ivakhnenko, E. P. et al. Synthesis and structure of nonacoordinated tris-chelate lanthanide (iii) complexes with tridentate 2,4,6,8-tetrakis(tert-butyl)-9-hydroxyphenoxazin-1-one ligands. Inorg. Chim. Acta, 2017, 458, 116-121.

63. Ivakhnenko, E. P. et al. Synthesis and structure of a tris-chelate gdiii complex with tridentate 2,4,6,8-tetrakis(tert-butyl)-9-hydroxyphenoxazinone ligands. Mendeleev Commun., 2016, 26, 49-51.

64. Cotton, S., Lanthanide and actinide chemistry. (John Wiley and Sons, West Sussex, U. K., 2006.

65. Feng, J.; Zhang, H. Hybrid materials based on lanthanide organic complexes: A review. Chem. Soc. Rev., 2013, 42, 387-410 (2013).

66. Walter, M. D.; Fandos, R.; Andersen, R. A. Synthesis and magnetic properties of cerium macrocyclic complexes with tetramethyldibenzotetraaza[14]annulene, tmtaah2. New J. Chem., 2006, 30, 1065-1070.

67. Behrle, A. C. et al. Stabilization of miv = ti, zr, hf, ce, and th using a selenium bis(phenolate) ligand. Dalton Trans. 2015, 44, 2693-2702.

68. Stults, S. D.; Andersen, R. A.; Zalkin, A. Chemistry of trivalent cerium and uranium metallocenes: Reactions with alcohols and thiols. Organometallics, 1990, 9, 1623-1629.

69. Evans, W. J.; Hozbor, M. A. Paramagnetism in organolanthanide complexes. J. Organomet. Chem. 1987, 326, 299-306.

70. Tian, G.; Shuh, D. K.; Beavers, C. M.; Teat, S. J. A structural and spectrophotometric study on the complexation of am(iii) with tmoga in comparison with the extracted complex of dmdooga. Dalton Trans. 2015, 44, 18469-18474. 71. Olekhnovich, L. P. et al. Tautomerism and stereodynamics in the series of sterically hindered ortho-substituted n-arylquinonimines. Dokl. Akad. Nauk. 1999, 369, 632-638. 103

72. Rai, D.; Strickert, R. G.; Ryan, J. L. Alpha radiation induced production of HNO3 during dissolution of Pu compounds (1). Inorg. Nucl. Chem. Lett. 1980, 16, 551-555 (1980).

73. Fischer, E. O., Laubereau, P., Baumgartner, F. & Kanellakopulos, B., J. Tricylopentadienylneptunium-chloride. Organomet. Chem. 1966, 5, 583-584.

74. Baumagartner, F., Fishcer, E. O., Kanellakopulos, B. and Laubereau, P., Angew. Chem., 1968, 80, 661-661.

75. Bohlander, R., The Organometallic Chemisty of Neptunium, 1968.

76. De Ridder, D. J A., Rebizant, J., Apostolidis, C., Kanellakopulos, B & Dornberger, E., Bis(cyclooctatetraenyl) neptunium (IV). Acta Cryst. C, 1996. 52, 597-600.

77. Magnani, N. et al. Magnetic memory effect in a transuranic mononuclear complex. Angew. Chem. Int. Ed., 2011, 50, 1696-1698.

78. Bursten, B. E., Rhodes, L. F., & Strittmatter, R. J., Less-Common Met. 1989, 149, 207-211.

79. Seaborg, G. T.; McMillan, E. M.; Kennedy, J. W.; Wahl, A. C. Radioactive element 94 from deuterons on uranium. Phys. Rev. 1946, 69, 366−367.

80. Reilly, S. D., Scott, B. L., and Gaunt, A. J., [N(n-Bu)4]2[Pu(NO3)6] and [N(n- Bu)4]2[PuCl6]: Starting Materials To Facilitate Nonaqueous Plutonium(IV) Chemistry. Inorg. Chem., 2012, 51, 9165-9167.

81. Huang, W., Upton, B. M., Khan, S. I., Diaconescu, P. L., Synthesis and characterization of paramagnetic lanthanide benzyl complexes. Organometallics, 2013, 32, 1379-1386.

82. Qiu, J.; Burns, P. C. Cluster of Actinides with Oxide, Peroxide, or Hydroxide Bridges. Chem. Rev. 2013, 113, 1097-1120.

83. Zanonato, P. L.; Bernardo, P. D.; Szabo, Z.; Grenthe, I. Chemical Equilibria in the Uranyl (Vi)-Peroxide-Carbonate System; Identification of Precursors for the Formation of Poly- peroxometallates. Dalton Trans., 2012, 41, 11635-11641.

84. Kubatko, K-A.; Helean, K. B.; Navrotsky, A.; Burns, P. C. Stability of Peroxide-Containing Uranyl Minerals. Science, 2003, 302,1191-1193.

85. Hasty, R. A.; Boggs, J. E., Isotopic Exchange Study on Thorium Peroxide. J. Inorg. Nucl. Chem., 1971, 33, 874-876.

86. Raman, V.; Jere, G. V. IR and Raman Studies on Thorium Peroxide. Indian J. Chem., 1973, 11, 1318-1319.

104

87. Jere, G. V.; Santhamma, M. T. Preparation, IR and Thermal Studies of Thorium Peroxide Species. J. Less Common Met. 1977, 52, 281-284.

88. Chernyshov, B. H.; Didenko, N. A.; Bukevetskii, B. V.; Gerasimenko, A. V.; Kavun, V.; Sergienko, S. S.; Preparation and Structure of the Polynuclear Fluoroperoxozirconate K6Zr3F12(O2)3.2H2O2.2H2O. Russ. J. Inorg. Chem., 1989, 34, 1594.

89. Lamb, A. C.; Lu, Z.; Xue, Z.-L. Reactions of Zirconium Amide Amidinates with Dioxygen. Observation of an Unusual Peroxo Intermediate in the Formation of Oxo Compounds. Chem. Commun, 2014, 50, 10517-10520.

90. Qiu, J.; Vlasisavljevich, B.; Jouffret, L.; Nguyen, K.; Szmanowski, J.; Gagliardi, L.; Burns, P. C. Cation Templating and Electronic Structure Effects in Uranyl Cage Clusters Probed by the Isolation of Peroxide-Brided Uranyl Dimers. Inorg. Chem., 2015, 54, 4445-4455.

91. Fang, B.; Ren, W.; Hou, G.; Zi, G.; Fang, D.; Maron, L.; Walter, M. D. An Actinide Metallacyclopropene Complex: Synthesis, Structure, Reactivity, and Computational Studies. J. Am Chem. Soc., 2014, 136, 17249-17261.

92. Diwu, J.; Grant, D. J.; Wang, S.; Gagliardi, L.; Albrecht-Schmitt, T. E. Periodic Trends in Lanthanide and Actinide phosphonates: Discontinuity Between Plutonium and Americium. Inorg. Chem., 2012, 51, 6906-6915.

93. Becke, A. D. A New Mixing of Hartree-Fock and Local-Density-Functional Theories. J. Chem. Phys., 1993, 98, 5648-5652.

94. Perdew, J. P.; Wang, Y. Accurate and Simple Analytic Representation of the Electron-Gas Correlation Energy. Phys. Rev. B, 1992, 45, 13244-13249.

95. Küchle, W.; Dolg, M.; Stoll, H.; Preuß, H. Energy-Adjusted Pseudopotentials for the Actinides. Parameter Sets and Test Calculation for Thorium and Thorium Monoxide. J. Chem. Phys. 1994, 100, 7535-7543.

96. Cao, X. Y.; Dolg, M.; Stoll, H. Valence Basis Sets for Relativistic Enegy-Consistent Small- Core Actinide Pseudopotentials. J. Chem. Phys. 2003, 118, 487-497.

97. Cao, X.; Dolg, M. Segmented Contraction Scheme for Small-Core Actinide Pseudopotential Basis Sets. J. Molec. Struct. (Theochem) 2004, 673, 203-209.

98. Moritz, A.; Cao, X. Y.; Dolg, M. Quasirelativistic Energy-Consistent 5f-in-Core Pseudopotentials for Divalent and Tetravalent Actinide Elements. Theor. Chem. Acc. 2007, 118, 845-854.

99. Hehre, W. J.; Ditchfield, R.; Pople, J. A. Self-Consistent Molecular Orbital Methods. XII> Further Extensions of Gaussian-Type Basis Sets for Use in Molecular Orbital Studies of Organic Molecules. J. Chem. Phys. 1972, 56, 2257–2261. 105

100. Hariharan, P. C.; Pople, J. A. The Influence of Polarization Functions on Molevular Orbital Hydrogenation Energies. Theor. Chim. Acta, 1973, 28, 213–222.

101. Binkley, J. S.; Pople, J. A.; Hehre, W. J. Self-Consistent Molecular Orbital Methods. 21. Small Split-Valence Basis Sets for First-Row Elements. J. Am. Chem. Soc., 1980, 102, 939- 947.

102. Gaussian 09, Revision A.02, Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Scalmani, G.; Barone, V.; Mennucci, B.; Petersson, G. A.; Nakatsuji, H.; Caricato, M.; Li, X.; Hratchian, H. P.; Izmaylov, A. F.; Bloino, J.; Zheng, G.; Sonnenberg, J. L.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Vreven, T.; Montgomery, Jr., J. A.; Peralta, J. E.; Ogliaro, F.; Bearpark, M.; Heyd, J. J.; Brothers, E.; Kudin, K. N.; Staroverov, V. N.; Kobayashi, R.; Normand, J.; Raghavachari, K.; Rendell, A.; Burant, J. C.; Iyengar, S. S.; Tomasi, J.; Cossi, M.; Rega, N.; Millam, J. M.; Klene, M.; Knox, J. E.; Cross, J. B.; Bakken, V.; Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.; Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Martin, R. L.; Morokuma, K.; Zakrzewski, V. G.; Voth, G. A.; Salvador, P.; Dannenberg, J. J.; Dapprich, S.; Daniels, A. D.; Farkas, O.; Foresman, J. B.; Ortiz, J. V.; Cioslowski, J.; Fox, D. J. Gaussian, Inc., Wallingford CT, 2009.

103. Zhurko, G. A. ChemCraft Home Page: a set of graphical tools for facilitating working with quantum chemistry computations (http://www.chemcraftprog.com).

104. Abrao, A. ; de Freitas, A. ; Sequeira de Carvalho, F. M. J. Alloys Compd., 2001, 323, 53-56.

105. Sheldrick, G. M. SHELXTL PC, Version 5.0, Siemens Analytical X-Ray Instruments, Inc.: Madison, WI 1994.

106. Johansson, B.; Rosengren, A. Generalized phase diagram for the rare-earth elements: Calculations and correlations of bulk properties. Phys. Rev. B. 1975, 11, 2836.

107. Smith, J. L.; Haire, R. G. Superconductivity of americium. Science. 1978, 200, 535-537.

108. Janoschek, M.; Das, P.; Chakrabarti, B.; Abernathy, D. L.; Lumsden, M. D.; Lawrence, J. M.; Thompson, J. D.; Lander, G. H.; Mitchell, J. N.; Richmond, S. The valence-fluctuating ground state of plutonium. Sci. Adv. 2015, 1, e1500188.

109. Janoschek, M.; Lander, G.; Lawrence, J. M.; Bauer, E.; Lashley, J. C.; Lumsden, M.; Abernathy, D. L.; Thompson, J. Relevance of Kondo physics for the temperature dependence of the bulk modulus in plutonium. Proc. Natl. Acad. Sci. U.S.A. 2017, 114, E268.

110. Söderlind, P.; Wills, J.; Johansson, B.; Eriksson, O. Structural properties of plutonium from first-principles theory. Phys. Rev. B. 1997, 55.

106

111. Karraker, D. G.; Stone, J. A.; Jones Jr, E. R.; Edelstein, N. Bis(cyclooctatetraenyl)neptunium(IV) and bis(cyclooctatetraenyl)plutonium(IV). J. Am. Chem. Soc. 1970, 92, 4841-4845.

112. Minasian, S. G.; Keith, J. M.; Batista, E. R.; Boland, K. S.; Clark, D. L.; Kozimor, S. A.; Martin, R. L.; Shuh, D. K.; Tyliszczak, T. New evidence for 5f covalency in actinocenes determined from carbon K-edge XAS and electronic structure theory. Chem. Sci. 2014, 5, 351-359.

113. Gregson, M.; Lu, E.; Tuna, F.; McInnes, E. J.; Hennig, C.; Scheinost, A. C.; McMaster, J.; Lewis, W.; Blake, A. J.; Kerridge, A. Emergence of comparable covalency in isostructural cerium(IV)–and uranium(IV)–carbon multiple bonds. Chem. Sci. 2016, 7, 3286-3297.

114. Silver, M. A.; Cary, S. K.; Stritzinger, J. T.; Parker, T. G.; Maron, L.; Albrecht-Schmitt, T. E. Covalency-Driven Dimerization of Plutonium(IV) in a Hydroxamate Complex. Inorg. Chem. 2016, 55, 5092-5094.

115. Adam, C.; Kaden, P.; Beele, B. B.; Müllich, U.; Trumm, S.; Geist, A.; Panak, P. J.; Denecke, M. A. Evidence for covalence in a N-donor complex of americium(III). Dalton Trans. 2013, 42, 14068-14074.

116. Schnaars, D. D.; Gaunt, A. J.; Hayton, T. W.; Jones, M. B.; Kirker, I.; Kaltsoyannis, N.; May, I.; Reilly, S. D.; Scott, B. L.; Wu, G. Bonding Trends Traversing the Tetravalent IV Ar Actinide Series: Synthesis, Structural, and Computational Analysis of An ( acnac)4 Ar t Complexes (An= Th, U, Np, Pu; acnac= ArNC(Ph) CHC (Ph)O; Ar= 3, 5- Bu2C6H3). Inorg. Chem. 2012, 51, 8557-8566.

117. Minasian, S. G.; Keith, J. M.; Batista, E. R.; Boland, K. S.; Clark, D. L.; Conradson, S. D.; Kozimor, S. A.; Martin, R. L.; Schwarz, D. E.; Shuh, D. K. Determining Relative f and d 2– – Orbital Contributions to M–Cl Covalency in MCl6 (M= Ti, Zr, Hf, U) and UOCl5 Using Cl K-Edge X-ray Absorption Spectroscopy and Time-Dependent Density Functional Theory. J. Am. Chem. Soc. 2012, 134, 5586-5597.

118. Nugent, L.; Baybarz, R.; Burnett, J.; Ryan, J. Electron-transfer and fd absorption bands of some lanthanide and actinide complexes and the standard (II-III) oxidation potential for each member of the lanthanide and actinide series. J. Phys. Chem. 1973, 77, 1528-1539.

3+ 119. Crosswhite, H.; Crosswhite, H.; Carnall, W.; Paszek, A. Spectrum analysis of U : LaCl3. J. Chem. Phys. 1980, 72, 5103-5117.

120. Sato, T.; Asai, M.; Borschevsky, A.; Stora, T.; Sato, N.; Kaneya, Y.; Tsukada, K.; Düllmann, C. E.; Eberhardt, K.; Eliav, E. Measurement of the first ionization potential of lawrencium, element 103. Nature. 2015, 520, 209-211.

107

121. Lukens, W. W.; Edelstein, N. M.; Magnani, N.; Hayton, T. W.; Fortier, S.; Seaman, L. A. Quantifying the σ and π interactions between U(V) f orbitals and halide, alkyl, alkoxide, amide and ketimide ligands. J. Am. Chem. Soc. 2013, 135, 10742-10754.

122. Verma, P.; Autschbach, J. Variational versus Perturbational Treatment of Spin–Orbit Coupling in Relativistic Density Functional Calculations of Electronic g Factors: Effects from Spin- Polarization and Exact Exchange. J. Chem. Theory Comput. 2013, 9, 1052-1067.

123. Cross, J. N.; Villa, E. M.; Wang, S.; Diwu, J.; Polinski, M. J.; Albrecht-Schmitt, T. E. Syntheses, structures, and spectroscopic properties of plutonium and americium phosphites and the redetermination of the ionic radii of Pu(III) and Am(III). Inorg. Chem. 2012, 51, 8419- 8424.

124. Xu, J.; Radkov, E.; Ziegler, M.; Raymond, K. N. Plutonium(IV) Sequestration: Structural and Thermodynamic Evaluation of the Extraordinarily Stable Cerium(IV) Hydroxypyridinonate Complexes1. Inorg. Chem. 2000, 39, 4156-4164.

125. Wilson, R. E. Structural periodicity in plutonium(IV) sulfates. Inorg. Chem. 2011, 50, 5663- 5670.

126. Diwu, J.; Nelson, A.-G. D.; Albrecht-Schmitt, T. E. Using phosphonates to probe structural differences between transuranium elements and their proposed surrogates. Comments Inorg. Chem. 2010, 31, 46-62.

127. Diwu, J.; Grant, D. J.; Wang, S.; Gagliardi, L.; Albrecht-Schmitt, T. E. Periodic trends in lanthanide and actinide phosphonates: Discontinuity between plutonium and americium. Inorg. Chem. 2012, 51, 6906-6915.

128. Diwu, J.; Nelson, A.-G. D.; Wang, S.; Campana, C. F.; Albrecht-Schmitt, T. E. Comparisons of Pu(IV) and Ce(IV) diphosphonates. Inorg. Chem. 2010, 49, 3337-3342.

129. Cross, J. N.; Duncan, P. M.; Villa, E. M.; Polinski, M. J.; Babo, J.-M.; Alekseev, E. V.; Booth, C. H.; Albrecht-Schmitt, T. From Yellow to Black: Dramatic changes between Ce(IV) and Pu(IV) Molybdates. J. Am. Chem. Soc. 2013, 135, 2769-2775.

130. Silver, M. A.; Albrecht-Schmitt, T. E. Evaluation of f-element borate chemistry. Coord. Chem. Rev. 2016, 323, 36-51.

131. Schott, J.; Kretzschmar, J.; Acker, M.; Eidner, S.; Kumke, M. U.; Drobot, B.; Barkleit, A.; Taut, S.; Brendler, V.; Stumpf, T. Formation of a Eu(III) borate solid species from a weak Eu(III) borate complex in aqueous solution. Dalton Trans. 2014, 43, 11516-11528.

132. Cary, S. K.; Galley, S. S.; Marsh, M. L.; Hobart, D. L.; Baumbach, R. E.; Cross, J. N.; Stritzinger, J. T.; Polinski, M. J.; Maron, L.; Albrecht-Schmitt, T. E. Incipient class II mixed valency in a plutonium solid-state compound. Nat. Chem. 2017.

108

133. Cary, S. K.; Ferrier, M. G.; Baumbach, R. E.; Silver, M. A.; Lezama Pacheco, J.; Kozimor, S. A.; La Pierre, H. S.; Stein, B. W.; Arico, A. A.; Gray, D. L. Monomers, Dimers, and Helices: Complexities of Cerium and Plutonium Phenanthrolinecarboxylates. Inorg. Chem. 2016, 55, 4373-4380.

134. Xu, J.; Durbin, P. W.; Kullgren, B.; Ebbe, S. N.; Uhlir, L. C.; Raymond, K. N. Synthesis and initial evaluation for in vivo chelation of Pu(IV) of a mixed octadentate spermine-based ligand containing 4-carbamoyl-3-hydroxy-1-methyl-2(1H)-pyridinone and 6-carbamoyl-1-hydroxy- 2(1H)-pyridinone. J. Med. Chem. 2002, 45, 3963-3971.

135. Sturzbecher-Hoehne, M.; Choi, T. A.; Abergel, R. J. Hydroxypyridinonate complex stability of group (IV) metals and tetravalent f-block elements: The key to the next generation of chelating agents for radiopharmaceuticals. Inorg. Chem. 2015, 54, 3462-3468.

136. Szigethy, G.; Xu, J.; Gorden, A. E.; Teat, S. J.; Shuh, D. K.; Raymond, K. N. Surprising Coordination Geometry Differences in CeIV‐and PuIV‐Maltol Complexes. Eur. J. Inorg. Chem. 2008, 2008, 2143-2147.

137. Miguirditchian, M.; Guillaneux, D.; Guillaumont, D.; Moisy, P.; Madic, C.; Jensen, M. P.; Nash, K. L. Thermodynamic study of the complexation of trivalent actinide and lanthanide cations by ADPTZ, a tridentate N-donor ligand. Inorg. Chem. 2005, 44, 1404-1412.

138. Jensen, M. P.; Bond, A. H. Comparison of covalency in the complexes of trivalent actinide and lanthanide cations. J. Am. Chem. Soc. 2002, 124, 9870-9877.

139. Wang, J.; Su, D.; Wang, D.; Ding, S.; Huang, C.; Huang, H.; Hu, X.; Wang, Z.; Li, S. Selective extraction of americium(III) over europium(III) with the pyridylpyrazole based tetradentate ligands: experimental and theoretical study. Inorg. Chem. 2015, 54, 10648-10655.

140. Martel, L.; Magnani, N.; Vigier, J.-F.; Boshoven, J.; Selfslag, C.; Farnan, I.; Griveau, J.-C.; Somers, J.; Fanghänel, T. High-resolution solid-state oxygen-17 NMR of actinide-bearing compounds: an insight into the 5f chemistry. Inorg. Chem. 2014, 53, 6928-6933.

141. Modolo, G.; Kluxen, P.; Geist, A. Demonstration of the LUCA process for the separation of americium(III) from curium(III), californium(III), and lanthanides(III) in acidic solution using a synergistic mixture of bis(chlorophenyl)dithiophosphinic acid and tris(2- ethylhexyl)phosphate. Radiochim. Acta. 2010, 98, 193-201.

142. Modolo, G.; Wilden, A.; Geist, A.; Magnusson, D.; Malmbeck, R. A review of the demonstration of innovative solvent extraction processes for the recovery of trivalent minor actinides from PUREX raffinate. Radiochim. Acta. 2012, 100, 715-725.

143. Marsh, M. L.; Albrecht-Schmitt, T. Directed Evolution of the Periodic Table: Probing the Electronic Structure of Heavy Actinides. Dalton Trans. 2017.

109

144. Cary, S. K.; Silver, M. A.; Liu, G.; Wang, J. C.; Bogart, J. A.; Stritzinger, J. T.; Arico, A. A.; Hanson, K.; Schelter, E. J.; Albrecht-Schmitt, T. E. Spontaneous partitioning of californium from curium: Curious cases from the crystallization of curium coordination complexes. Inorg. Chem. 2015, 54, 11399-11404.

145. Dupouy, G.; Bonhoure, I.; Conradson, S. D.; Dumas, T.; Hennig, C.; Le Naour, C.; Moisy, P.; Petit, S.; Scheinost, A. C.; Simoni, E. Local structure in americium and californium hexacyanoferrates–comparison with their lanthanide analogues. Eur. J. Inorg. Chem. 2011, 2011, 1560-1569.

146. Wall, T. F.; Jan, S.; Autillo, M.; Nash, K. L.; Guerin, L.; Naour, C. L.; Moisy, P.; Berthon, C. Paramagnetism of Aqueous Actinide Cations. Part I: Perchloric Acid Media. Inorg. Chem. 2014, 53, 2450-2459.

147. Leguay, S. b.; Vercouter, T.; Topin, S.; Aupiais, J.; Guillaumont, D.; Miguirditchian, M.; Moisy, P.; Le Naour, C. New insights into formation of trivalent actinides complexes with DTPA. Inorg. Chem. 2012, 51, 12638-12649.

148. Dau, P. D.; Shuh, D. K.; Sturzbecher-Hoehne, M.; Abergel, R. J.; Gibson, J. K. Divalent and trivalent gas-phase coordination complexes of californium: evaluating the stability of Cf(II). Dalton Trans. 2016, 45, 12338-12345.

149. Deblonde, G. J.-P.; Sturzbecher-Hoehne, M.; Rupert, P. B.; An, D. D.; Illy, M.-C.; Ralston, C. Y.; Brabec, J.; de Jong, W. A.; Strong, R. K.; Abergel, R. J. Chelation and stabilization of berkelium in oxidation state +IV. Nat. Chem. 2017.

150. MacDonald, M. R.; Bates, J. E.; Ziller, J. W.; Furche, F.; Evans, W. J. Completing the series of+ 2 ions for the lanthanide elements: Synthesis of molecular complexes of Pr2+, Gd2+, Tb2+, and Lu2+. J. Am. Chem. Soc. 2013, 135, 9857-9868.

151. Fieser, M. E.; MacDonald, M. R.; Krull, B. T.; Bates, J. E.; Ziller, J. W.; Furche, F.; Evans, W. J. Structural, spectroscopic, and theoretical comparison of traditional vs recently discovered 2+ 2+ Ln ions in the [K (2.2. 2-cryptand)][(C5H4SiMe3)3Ln] complexes: the variable nature of Dy and Nd2+. J. Am. Chem. Soc. 2014, 137, 369-382.

152. Windorff, C. J.; MacDonald, M. R.; Meihaus, K. R.; Ziller, J. W.; Long, J. R.; Evans, W. J. Expanding the Chemistry of Molecular U2+ Complexes: Synthesis, Characterization, and − Reactivity of the {[C5H3(SiMe3)2]3U} Anion. Chem. Eur. J. 2016, 22, 772-782.

153. Kelley, M. P.; Su, J.; Urban, M.; Luckey, M.; Batista, E. R.; Yang, P.; Shafer, J. C. On the Origin of Covalent Bonding in Heavy Actinides. J. Am. Chem. Soc. 2017.

154. Choppin, G.; Morgenstern, A. Radionuclide separations in radioactive waste disposal. J. Radioanal. Nucl. Chem. 2000, 243, 45-51.

110

155. Lukens, W. W.; Magnani, N.; Tyliszczak, T.; Pearce, C. I.; Shuh, D. K. Incorporation of technetium into spinel ferrites. Environ. Sci. Technol. 2016, 50, 13160-13168.

156. Krivovichev, S.; Burns, P.; Tananaev, I. Structural chemistry of inorganic actinide compounds; Elsevier, 2006.

157. Sullens, T. A.; Albrecht-Schmitt, T. E. Thorium(IV) chromate(VI) monohydrate. Acta Crystallogr. Sect. Sect. E: Struct. Rep. Online. 2006, 62, i258-i260.

158. Sigmon, G. E.; Burns, P. C. Crystal chemistry of thorium nitrates and chromates. J. Solid State Chem. 2010, 183, 1604-1608.

159. Krivovichev, S. V.; Burns, P. C. The first sodium uranyl chromate, Na4[(UO2)(CrO4)3]: synthesis and crystal structure determination. Z. Anorg. Allg. Chem. 2003, 629, 1965-1968.

160. Siidra, O. I.; Nazarchuk, E. V.; Krivovichev, S. V. Isopropylammonium layered uranyl chromates: syntheses and crystal structures of [(CH3)2CHNH3]3[(UO2)3(CrO4)2O(OH)3] and [(CH3)2CHNH3]2[(UO2)2(CrO4)3(H2O)]. Z. Anorg. Allg. Chem. 2012, 638, 976-981.

161. Siidra, O. I.; Nazarchuk, E. V.; Krivovichev, S. V. Unprecedented Bidentate Coordination of the Uranyl Cation by the Chromate Anion in the Structure of [(CH3)2CHNH3]2[UO2(CrO4)2]. Eur. J. Inorg. Chem. 2012, 2012, 194-197.

162. Siidra, O. I.; Nazarchuk, E. V.; Krivovichev, S. V. Highly Kinked Uranyl Chromate Nitrate Layers in the Crystal Structures of A [(UO2)(CrO4)(NO3)] (A= K, Rb). Z. Anorg. Allg. Chem. 2012, 638, 982-986.

163. Fedoseev, A.; Budantseva, N.; Grigor'ev, M.; Perminov, V. Synthesis and study of the properties of chromate compounds of pentavalent neptunium and americium. Radiokhimiya. 1991, 33, 7-19.

164. Charushnikova, I.; Fedoseev, A. Synthesis and crystal structure of americium(V) dichromate, Cs3AmO2(Cr2O7)2 · H2O. Radiochemistry. 2013, 55, 11-15.

165. Melnikov, P.; Parada, C.; Bueno, I.; Moran, E. On rubidium lanthanide double chromates. J. Alloys Compd. 1993, 190, 265-267.

166. Melnikov, P.; Bueno, I.; Parada, C.; Morán, E.; León, C.; Santamaría, J.; Sánchez-Quesada, F. A study of ionic conductivity in double rare-earth chromates. Solid State Ionics. 1993, 63, 581- 584.

167. Melnikov, P.; Ferracin, L. Synthesis and characterization of β-RbSc(CrO4)2. J. Alloys Compd. 1995, 224, L5-L6.

111

168. Ruiz‐Martínez, A.; Casanova, D.; Alvarez, S. Polyhedral Structures with an Odd Number of Vertices: Nine‐Coordinate Metal Compounds. Chem. Eur. J. 2008, 14, 1291-1303.

169. Kuzina, T.; Shakhno, I.; Krachak, A.; Plyushchev, V. Study on formation conditions for double chromates of neodymium and samarium with cesium in solutions. Zhurnal Neorganicheskoj Khimii. 1973, 18, 2727-2730.

170. Bueno, I.; Parada, C.; García, O.; Puebla, E. G.; Monge, A.; Valero, C. R. Crystal growth, structure, and properties of KLa (CrO4)2. J. Chem. Soc., Dalton Trans. 1988, 1911-1914.

171. Bueno, I.; Garcia, O.; Parada, C.; Puche, R. S. Crystal growth, IR and Raman spectra, thermal decomposition and magnetic properties of KLn (CrO4)2 (Ln≡ Pr, Nd, Sm). J. Less-Common MET. 1988, 139, 261-271.

172. Bueno, I.; Parada, C.; Puche, R. S.; Botto, I.; Baran, E. Synthesis, crystallographic data, magnetic properties and vibrational study of the new series KLn(CrO4)4 (Ln= Eu, Gd, Tb). J. Phys. Chem. Solids. 1990, 51, 1117-1121.

173. Bueno, I.; Parada, C.; Hermoso, J.; Vegas, A.; Marti, M. Crystal growth and crystal structure of KTb (CrO4)2. J. Solid State Chem. 1990, 85, 83-87.

174. Runde, W.; Bean, A. C.; Brodnax, L. F.; Scott, B. L. Synthesis and Characterization of f- Element Iodate Architectures with Variable Dimensionality, α-and β-Am (IO3)3. Inorg. Chem. 2006, 45, 2479-2482.

175. Sykora, R. E.; Assefa, Z.; Haire, R. G.; Albrecht-Schmitt, T. E. First structural determination of a trivalent californium compound with oxygen coordination. Inorg. Chem. 2006, 45, 475- 477.

176. Sykora, R. E.; Assefa, Z.; Haire, R. G.; Albrecht-Schmitt, T. E. Hydrothermal synthesis, 248 structure, Raman spectroscopy, and self-irradiation studies of Cm(IO3)3. J. Solid State Chem. 2004, 177, 4413-4419.

177. Douglas, P.; Hector, A. L.; Levason, W.; Light, M. E.; Matthews, M. L.; Webster, M. Hydrothermal Synthesis of Rare Earth Iodates from the Corresponding Periodates: II1). Synthesis and Structures of Ln(IO3)3 (Ln= Pr, Nd, Sm, Eu, Gd, Tb, Ho, Er) and Ln(IO3)3 · 2H2O (Ln= Eu, Gd, Dy, Er, Tm, Yb). Z. Anorg. Allg. Chem. 2004, 630, 479-483.

178. Nassau, K.; Shiever, J.; Prescott, B. Transition metal iodates. VI. Preparation and characterization of the larger lanthanide iodates. J. Solid State Chem. 1975, 14, 122-132.

179. Nassau, K.; Shiever, J.; Prescott, B.; Cooper, A. Transition metal iodates. V. Preparation and characterization of the smaller lanthanide iodates. J. Solid State Chem. 1974, 11, 314-318.

180. Abrahams, S.; Bernstein, J.; Nassau, K. Transition metal iodates. VII. Crystallographic and nonlinear optic survey of the 4f-iodates. J. Solid State Chem. 1976, 16, 173-184. 112

181. Abrahams, S.; Sherwood, R.; Bernstein, J.; Nassau, K. Transition metal iodates. II. Crystallographic, magnetic, and nonlinear optic survey of the 3d iodates. J. Solid State Chem. 1973, 7, 205-212.

182. Bentria, B.; Benbertal, D.; Bagieu-Beucher, M.; Masse, R.; Mosset, A. Crystal structure of anhydrous bismuth iodate, Bi(IO3)3. J. Chem. Crystallogr. 2003, 33, 867-873.

183. Hector, A. L.; Henderson, S. J.; Levason, W.; Webster, M. Hydrothermal synthesis of rare earth iodates from the corresponding periodates: structures of Sc(IO3)3, Y(IO3)3 · 2H2O, La(IO3)3 · 1/2H2O and Lu(IO3)3 · 2H2O. Z. Anorg. Allg. Chem. 2002, 628, 198-202.

184. Phanon, D.; Mosset, A.; Gautier-Luneau, I. New iodate materials as potential laser matrices. Preparation and characterisation of α-M (IO3)3 (M= Y, Dy) and β-M (IO3)3 (M= Y, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Ho, Er). Structural evolution as a function of the Ln3+ cationic radius. Solid State Sci. 2007, 9, 496-505.

185. Wybourne, B. G. Spectroscopic properties of rare earths; Interscience New York, 1965.

186. Sykora, R. E.; Assefa, Z.; Haire, R. G.; Albrecht-Schmitt, T. E. Synthesis, structure, and spectroscopic properties of Am(IO3)3 and the photoluminescence behavior of Cm(IO3)3. Inorg. Chem. 2005, 44, 5667-5676.

187. Tassell, M. J.; Kaltsoyannis, N. Covalency in AnCp4 (An= Th–Cm): A comparison of molecular orbital, natural population and atoms-in-molecules analyses. Dalton Trans. 2010, 39, 6719-6725.

188. Kirker, I.; Kaltsoyannis, N. Does covalency really increase across the 5f series? A comparison of molecular orbital, natural population, spin and electron density analyses of AnCp3 (An= Th– 5 Cm; Cp= η -C5H5). Dalton Trans. 2011, 40, 124-131.

189. Kaltsoyannis, N. Covalency hinders AnO2 (H2O)+→ AnO(OH)2+ isomerisation (An= Pa–Pu). Dalton Trans. 2016, 45, 3158-3162.

190. Lanatà, N.; Strand, H. U.; Yao, Y.; Kotliar, G. Principle of Maximum Entanglement Entropy and Local Physics of Strongly Correlated Materials. Phys. Rev. Lett. 2014, 113, 036402.

191. Lanata, N.; Yao, Y.-X.; Wang, C.-Z.; Ho, K.-M.; Schmalian, J.; Haule, K.; Kotliar, G. γ− α isostructural transition in cerium. Phys. Rev. Lett. 2013, 111, 196801.

192. Sheldrick, G. M. SHELXT–Integrated space-group and crystal-structure determination. Acta Cryst. A. 2015, 71, 3-8.

193. Spek, A. L. Structure validation in chemical crystallography. Acta Crystallogr. Sect. D. Biol. Crystallogr. 2009, 65, 148-155.

113

194. Frisch, M.; Trucks, G.; Schlegel, H. B.; Scuseria, G.; Robb, M.; Cheeseman, J.; Scalmani, G.; Barone, V.; Mennucci, B.; Petersson, G.et al.; Gaussian, Inc., Wallingford CT, 2009.

195. Cao, X.; Dolg, M. Segmented contraction scheme for small-core actinide pseudopotential basis sets. J. Mol. Struc.-THEOCHEM. 2004, 673, 203-209.

196. Cao, X.; Dolg, M.; Stoll, H. Valence basis sets for relativistic energy-consistent small-core actinide pseudopotentials. J. Chem. Phys. 2003, 118, 487-496.

197. Leininger, T.; Nicklass, A.; Küchle, W.; Stoll, H.; Dolg, M.; Bergner, A. The accuracy of the pseudopotential approximation: Non-frozen-core effects for spectroscopic constants of alkali fluorides XF (X= K, Rb, Cs). Chem. Phys. Lett. 1996, 255, 274-280.

198. Adamo, C.; Barone, V. Toward reliable density functional methods without adjustable parameters: The PBE0 model. J. Chem. Phys. 1999, 110, 6158-6170.

199. Keith, T. A. AIMAll v 16.01.09. http://aim.tkgristmill.com, 2015.

200. Glendening, E.; Badenhoop, J.; Reed, A.; Carpenter, J.; Bohmann, J.; Morales, C.; Landis, C.; Weinhold, F. In Theoretical Chemistry Institute, University of Wisconsin, Madison, WI, 2013.

201. Gunnarsson, O.; Lundqvist, B. I. Exchange and correlation in atoms, molecules, and solids by the spin-density-functional formalism. Phys. Rev. B. 1976, 13, 4274.

202. Georges, A.; Kotliar, G.; Krauth, W.; Rozenberg, M. J. Dynamical mean-field theory of strongly correlated fermion systems and the limit of infinite dimensions. Rev. Mod. Phys. 1996, 68, 13.

203. Anisimov, V.; Poteryaev, A.; Korotin, M.; Anokhin, A.; Kotliar, G. First-principles calculations of the electronic structure and spectra of strongly correlated systems: dynamical mean-field theory. J. Phys.: Condens. Matter. 1997, 9, 7359.

204. Lichtenstein, A.; Katsnelson, M. Antiferromagnetism and d-wave superconductivity in cuprates: A cluster dynamical mean-field theory. Phys. Rev. B. 2000, 62, R9283. 205. Gutzwiller, M. C. Correlation of electrons in a narrow s band. Phys. Rev. 1965, 137, A1726.

206. Deng, X.; Wang, L.; Dai, X.; Fang, Z. Local density approximation combined with Gutzwiller method for correlated electron systems: Formalism and applications. Phys. Rev. B. 2009, 79, 075114.

207. Lanatà, N.; Yao, Y.; Wang, C.-Z.; Ho, K.-M.; Kotliar, G. Phase Diagram and Electronic Structure of Praseodymium and Plutonium. Phys. Rev. X. 2015, 5, 011008.

208. Lanatà, N.; Yao, Y.; Deng, X.; Dobrosavljević, V.; Kotliar, G. Slave Boson Theory of Orbital Differentiation with Crystal Field Effects: Application to UO2. Phys. Rev. Lett. 2017, 118, 126401. 114

209. Blaha, P.; Schwarz, K.; Madsen, G.; Kvasnicka, D.; Luitz, J. Wien2K: An Augmented Plane Wave Plus Local Orbitals Program for Calculating Crystal Properties (Karlheinz Schwarz, Techn. Universität Wien, Austria, 2001). Google Scholar.

210. Haule, K.; Yee, C.-H.; Kim, K. Dynamical mean-field theory within the full-potential methods: Electronic structure of CeIrIn5, CeCoIn5, and CeRhIn5. Phys. Rev. B. 2010, 81, 195107.

211. Werner, P.; Comanac, A.; De’Medici, L.; Troyer, M.; Millis, A. J. Continuous-time solver for quantum impurity models. Phys. Rev. Lett. 2006, 97, 076405.

115

BIOGRAPHICAL SKETCH

Education and Professional Experience: Florida State University, Tallahassee, FL • Ph.D. in Inorganic Chemistry, current Ithaca College, Ithaca, NY • B.S. in Chemistry with Honors, May 2013

Education: Florida State University, Tallahassee, FL Graduate Student: Research Advisor: Prof. Thomas E. Albrecht-Schmitt Thesis title: TBD Start Date: January 2013 Graduation: December 2017

• Investigated periodic trends in the actinide series, especially in mid- to late actinides from plutonium to californium using N-donor ligands under non-aqueous conditions • Synthesized new crystalline complexes and materials using solution reactions, schlenk line and glovebox techniques • Characterized new materials using a single crystal X-ray diffraction, magnetic susceptibility, and a variety of photophysical techniques that include variable temperature UV-vis-NIR absorption spectroscopy, photoluminescence, and luminescence life-time measurements.

Ithaca College, Ithaca, NY Undergraduate Student: Research Advisor: Prof. Anna S. Larsen Thesis title: Rhodium Pincer Catalysts for Alkyne Dimerization Start Date: September 2010 Graduation: May 2013

• Investigated PNP ligands rhodium catalysis for dimerization of alkyne in the formation of 1,3 enynes • Synthesized rhodium complexes and various PNP ligands using glovebox and schlenk line techniques • Characterized new materials using a single crystal X-ray diffraction, GC-mass spec, and NMR

Awards and Grants:

• 2015 General Chemistry Outstanding Teaching Assistant Award • Nominated for the 2015-2016 Outstanding Teaching Assistant Award (OTAA) • Summer 2012 Dana Scholarship for Undergraduate Research

116

Areas of Expertise: • Solving single crystal and extended structures using programs such as: SHELX program package and Platon. • Techniques and protocols for handling highly radioactive materials. Isotopes worked with include: 99Tc, 232Th, 238U, 237Np, 239Pu, 242Pu, 243Am, 248Cm, 249Bk, 249Cf, 253Es • Crystal growth via hydrothermal, solvothermal, and evaporation methods. • Working with air-sensitive materials (glove box, Schlenk line). • Recycling and purification of actinides (Pu, Am, Cm, Bk, Cf) • Other techniques: Two-dimensional 1HNMR (COSY), HPLC, UV-vis, X-Ray Fluorescence (XRF), Powder X-Ray diffraction, Atomic Absorption/Emission Spectroscopy, GC-mass spec.

Teaching Experience: • Teaching Assistant Fall 2013- Fall 2015 Florida State University • Teaching Assistant Fall 2012- Spring 2013 Ithaca College • Served as Teaching Assistant for general chemistry, biochemistry, general chemistry and biochemistry laboratories • Mentor to 5 undergraduate research assistance, Florida State University

Publications:

1. Galley, S. S.; Arico, Alexandra; Lee, Tsung-Han; Yao, Yong-Xin; Deng, Xiaoyu; Storbeck, Julia; Dobrosavljevic, Vlad; Albrecht-Schmitt, Thomas; Kaltsoyannis, Nikolas; Lanata, Nicola. “Uncovering the Origin of Divergence in the CsM(CrO4)2 (M = La ‒ Sm; Am) Family through Examination of the Chemical Bonding in a Molecular Cluster and by Band Structure Analysis" J. Am. Chem. Soc. In Review

2. Galley, S. S.; Van Alstine, C. E.; Maron, L.; Albrecht-Schmitt, T. E.; Understanding the Scarcity of Thorium Peroxide Clusters’ Inorg. Chem. Accepted

3. Silver, M. A.; Cary, S. K.; Garza, A. J.; Baumbach, R. E.; Arico, A. A.; Galmin, G. A., Chen, K.; Johnson, J. A.; Wang, J. C.; Clark, R. J.; Chemey, A.; Eaton, T. M.; Marsh, M. L.; Seidler, K.; Galley, S. S.; et al. “Electronic Structure and Properties of Berkelium Iodates” J. Am. Chem. Soc., 2017, 139, 133361-13375.

4. Cary, S. K.; Galley, S. S.; Marsh, M. L.; Hobart, D. E.; Baumbach, R. E.; Cross, J. N.; Stritzinger, J. T.; Polinski, M. J.; Marion, L.; Albrecht-Schmitt, T. E. “Incipient Class II Mixed-Valency in a Plutonium Solid-State Compound” Nature Chem. 2017

5. Muller, J. M.; Galley, S. S.; Albrecht-Schmitt, T. E.; Nash, K. L. “Characterization of Lanthanide Complexes with Bis-1,2,3-triazole-bipyridine Ligands involved in Actinide/Lanthanide Separation” Inorg. Chem., 2016, 55, 11454-11461.

117

Manuscripts in Progress:

6. Galley, S. S.; Pattenaude, S. A.; Chen, Y.; Gaglioli, C.; Schelter, E.; Gagliardi, L.; Albrecht-Schmitt, T. E.; Bart, S. C.; “Using Redox-Active Ligands to Understand Bonding in Trivalent Bonding in Trivalent Actindes” To be submitted to Nature Chem.

7. Pattenaude, S. A.; Galley, S.S.; Albrecht-Schmitt, T. E.; Bart, S. C. “Using Redox-Active Ligands to Understand Bonding in Tetravalent Bonding in Actinides”

8. Galley, S. S.; Branson, J. A.; Nowatarski, M. S.; Barros, C.; Albrecht-Schmitt, T. E. “Tris Terpyridine complexes for Probing Bonding in Trivalent Actinides”

9. Galley, S. S.; Van Alstine, C. E.; Barros, C.; Albrecht-Schmitt, T. E. “ Sulfur based ligands for Probing Trivalent Lanthanides”

10. Galley, S.S. Albrecht-Schmitt, Bart, S. C. “Anhydrous Am starting material for Organometallic chemistry”

Presentations:

1. Galley. S. S.; Albrecht-Schmitt, T. E. “Investigation of Trivalent Actinides utilizing a Redox active ligand” ACS, March 2017

2. Galley. S. S.; Pattenaude, S. A.; Bart, S. C., Albrecht-Schmitt, T. E. “Investigation of Trivalent Actinides utilizing a Redox active ligand” ACS, March 2017

3. Galley, S. S.; Pattenaude, S. A.; Bart, S. C., Albrecht-Schmitt, T. E. “Investiong of Trivalent Actinides utilizing a Redox active ligand” Plutonium Futures September 2016

4. Galley, S. S.; “Investigation of Ln/An bonding with N-hetereocycle ligands” NASSCC May 2015

5. Galley, S. S.; Cary, S. K.; Albrecht-Schmitt, T. E.; “ Insert title” International Actinide Coordination Chemistry Symposium. October 2014

6. Galley, S. S.; Larsen, A. S.; Ozerov, O. V. “ Targeting conjugated enyne isomers via rhodium pincer catalyst advances” ACS, April 2013

Invited Talks

1. Ithaca College, October 2017

118