UCLA Electronic Theses and Dissertations

UCLA UCLA Electronic Theses and Dissertations

Title Synthesis of Ferrocene-Based Ligands and Their Applications in Redox-Switchable Catalysis for Selective Hydroamination Reactions

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Author Lydon, Brian Raymond

Publication Date 2013

Peer reviewed|Thesis/dissertation

eScholarship.org Powered by the California Digital Library University of California UNIVERSITY OF CALIFORNIA Los Angeles

Synthesis of Ferrocene-Based Ligands and Their Applications in Redox-Switchable Catalysis for Selective Hydroamination Reactions

A thesis submitted in partial satisfaction of the requirements for the degree Master of Science in Chemistry

Brian Raymond Lydon

2013

ABSTRACT OF THE THESIS

Synthesis of Ferrocene-Based Ligands and Their Applications in Redox-Switchable Catalysis for Selective Hydroamination Reactions

Brian Raymond Lydon

Master of Science in Chemistry University of California, Los Angeles, 2013 Professor Paula L. Diaconescu, Chair

This thesis contains results from three different projects. The first project focused on the synthesis of monoanionic ferrocene-based N,P ligands. 1-(tert-butyldimethylsilyl)amino-1’- diphenylphosphinoferrocene (fc(TBSNH)(PPh2)) was successfully synthesized and characterized by 1H, 31P, 13C NMR spectroscopy, and elemental analysis. Unfortunately, coordination to group

3 metal complexes was unsuccessful.

The second project focused on the synthesis of redox-active ferrocene-based ligands and their applications in selective intramolecular hydroamination. Redox-active ligands can be used as a reversible trigger to control catalytic reactivity. Preliminary results observed by 1H NMR spectroscopy suggest that [1,1’-ferrocenedi(thio(3,5-di-tert-butyl-2-phenoxide)]Zr dibenzyl

2 ((thiolfan )ZrBn2) shows selectivity between primary and secondary alkeneamines depending on the oxidation state of the iron center.

The final project was a computational study using density functional theory (DFT) to understand recent experimental findings involving ferrocene-functionalized biodegradable polymers. Gibbs free energy for six cyclic carbonate monomers and three δ-valerolactone monomers was calculated. Computational results correlated strongly with experimental data in that δ-valerolactones, which could not be polymerized, had a higher Gibbs free energy than cyclic carbonates, which could be polymerized.

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The thesis of Brian Raymond Lydon is approved.

Anastassia Alexandrova Ohyun Kwon Paula L. Diaconescu, Committee Chair

University of California, Los Angeles 2013

Table of contents Title Page ...... i Abstract ...... ii Committee Page ...... iv Table of Contents ...... v List of Figures and Tables ...... vii List of Abbreviations ...... ix Acknowledgments ...... x Chapter 1: Ferrocene Ligand Synthesis ...... 1 1.1 Introduction ...... 1 1.1.1 Background on Ferrocene ...... 1 1.1.2 Ferrocene Ligands and Their Properties ...... 2 1.1.3 1-amino-1'-diphenylphosphinoferrocene ...... 3 1.2 Results and Discussion ...... 4 i 1.2.1 Synthesis of fcBr(PPh2) and fcBr(P Pr2) ...... 5 1.2.2 Synthesis of fc(NH2)(PPH2) ...... 7 1.2.3 Synthesis of fc(TBSNH)(PPH2) ...... 8 1.2.4 Attempts to Form Metal Complexes ...... 9 1.3 Conclusions ...... 10 1.4 Experimental Section ...... 10 1.4.1 General Considerations ...... 10

1.4.2 Preparation of fcBr(PPh2) ...... 11 i 1.4.3 Preparation of fcBr(P Pr2) ...... 12 1.4.4 Preparation of fc(NH2)(PPh2) ...... 13 1.4.5 Preparation of fc(TBSNH)(PPh2) ...... 14 1.5 Supplementary Material ...... 15 1.6 References ...... 19 Chapter 2: Part 1 Redox-Active Ferrocene Ligands ...... 21 2.1 Introduction ...... 21 2.1.1 Hydroamination Background ...... 21 2.1.2 Redox-Active Ligand Background ...... 22 2.2 Results and Discussion ...... 24 2.2.1 Phase One of Redox-switchable Selective Hydroamination ...... 25

2.2.2 Phase Two of Redox-switchable Selective Hydroamination ...... 26 2 2.2.3 Synthesis of (thiolfan )Zr(NEt2)2 ...... 27 2.3 Conclusions ...... 28 2.4 Experimental Section ...... 28 2.4.1 General Considerations ...... 28 2.4.2 General Procedure for Hydroamination Reactions with Neutral Catalysts ...... 29 2.4.3 General Procedure for Hydroamination Reactions with Oxidized Catalysts ...... 29 2 2.4.4 Preparation of (thiolfan )Zr(NEt2)2 ...... 29 2 2.4.5 Oxidation of (thiolfan )Zr(NEt2)2 ...... 30 2.5 Supplementary Material ...... 31 2.6 References ...... 33 Chapter 3: Computational Study of Ferrocene-functionalized Polymers ...... 35 3.1 Introduction ...... 35 3.1.1 Background on Ferrocene in Polymers and Materials ...... 35 3.1.2 Overview of Current Projects in Biodegradable Polymers ...... 35 3.2 Results and Discussion ...... 37 3.3 Conclusions ...... 43 3.4 Supplementary Material ...... 43 3.5 References ...... 65

List of Figures and Tables Chapter 1: Ferrocene Ligand Synthesis Figure 1. Structure of ferrocene determined by Woodward and Wilkinson ...... 1 Figure 2. General framework of the Diaconescu group’s ferrocene-based ligands ...... 2 Figure 3. Iron-metal bond evidence in a ferrocenediamide metal complex through molecular orbital overlap ...... 3

Figure 4. fc(TBSNH)(PPh2) synthetic scheme 5 steps ...... 4 Figure 5. Chemical equation for fcBr(PR2) ...... 5 Figure 6. Chemical equation for fc(NH2)(PR2)...... 7 Figure 7. Chemical equation for fc(TBSNH)(PPh2) ...... 8 1 Figure 8. H NMR spectrum of fcBr(PPH2) (CDCl3) ...... 15 31 Figure 9. P NMR spectrum of fcBr(PPh2) (CDCl3) ...... 15 1 i Figure 10. H NMR spectrum of fcBr(P Pr2) (CDCl3) ...... 16 31 i Figure 11. P NMR spectrum of fcBr(P Pr2) (CDCl3) ...... 16 1 Figure 12. H NMR spectrum of fc(NH2)(PPh2) (CDCl3) ...... 17 31 Figure 13. P NMR spectrum of fc(NH2)(PPh2) (CDCl3) ...... 17 1 Figure 14. H NMR spectrum of fc(TBSNH)(PPH2) (C6D6) ...... 18 31 Figure 15. P NMR spectrum of fc(TBSNH)(PPH2) (C6D6) ...... 18 13 Figure 16. C NMR spectrum of fc(TBSNH)(PPH2) (C6D6)...... 19 Chapter 2: Redox-Active Ferrocene Ligands and Applications in Hydroamination Figure 1. General examples of hydroamination reactions ...... 21 Figure 2. General example of intramolecular hydroamination reactions with neutral zirconium catalysts...... 22 Figure 3. General example of the redox activity for ferrocene-based ligands ...... 23

Figure 4. Evolution of H2(salfan) and H2(thiolfan) ...... 24 Figure 5. Redox-swtichable zirconium catalysts used for intramolecular hydroamination study...... 24 2 Figure 6. Chemical equation for (thiolfan )Zr(NEt2)2 ...... 27 1 2 Figure 7. H NMR spectrum of (thiolfan )Zr(NEt2)2 (C6D6) ...... 31 Figure 8. 1H NMR spectrum of time-monitored experiment. Neutral (thiolfan2)ZrBn2 with primary hydroamination substrate. (C6D6) ...... 31 Figure 9. 1H NMR spectrum of time-monitored experiment. Neutral 2 (thiolfan )ZrBn2 with secondary hydroamination substrate. (C6D6) ...... 32 Figure 10. 1H NMR spectrum of time-monitored experiment. Oxidized 2 (thiolfan )ZrBn2 with secondary hydroamination substrate. (C6D6)...... 32 Figure 11. 1H NMR spectrum of time-monitored control experiment. Secondary F hydroamination substrate plus AcFcBAr , no catalyst (C6D6) ...... 33

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Chapter 3: Computational Study for Ferrocene-functionalized Polymers Figure 1. Pre-optimized structures of ring-closed monomers used in polymerization and computational study ...... 36 Table 1. Summary of both the Gibbs free energy and the enthalpy of reaction for the ring-opening reaction of each geometry optimized monomer ...... 38 Figure 2. Optimized structures of all ring-closed monomers (RCM) and ring-opened monomers (ROM)...... 39

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List of Abbreviations and Symbols α alpha δ delta Δ delta η eta Σ sigma Fc ferrocenium fc 1,1’-ferrocenediyl Ph phenyl Bn benzyl eq equivalent Pet petroleum Cp cyclopentadienyl TMEDA N,N,N′,N′-tetramethylethane-1,2-diamine Ac acetyl Et ethyl Me methyl tBu tert-butyl Dppf diphenylphosphinoferrocene THF tetrahydrofuran iPr iso-propyl NMR nuclear magnetic resonance TBS tert-butyldimethylsilyl BArF tetrakis[3,5-bis(trifluoromethyl)phenyl]borate LAH lithium aluminum hydride DCM dichloromethane ppm parts per million ROM ring-opened monomer RCM ring-closed monomer DFT density functional theory EA elemental analysis

Acknowledgments

There are a handful of people who helped me through my two-year research experience at

UCLA that I would like to personally thank and acknowledge, because without them this thesis would not be possible. I would like to first thank my advisor, Professor Paula Diaconescu, for the opportunity to participate in her laboratory and for all of the effort she has put into shaping me into a good scientist. I started in her lab barely understanding the definition of a ligand and by graduation I had become an experienced synthetic inorganic chemist thanks to her guidance. I hope I can continue to uphold the level of excellence and expectations she has instilled within me throughout my future doctoral studies and career.

I would also like to thank all of the mentors I have had over the past two years: Aaron

Green, for initially taking me under his wing and gradually allowing me to become an independent chemist; Brianna Upton, for developing my synthetic techniques and putting up with me even when I may have accidentally killed one or two of her compounds; and, most importantly, I would like to truly express my gratitude towards Kirk Wang. While allowing me to work under him and learn from his incredible knowledge of chemistry, Kirk taught me the true meaning of productivity and work ethic. The most important piece of advice that I will take from the Diaconescu lab is from Kirk stating, “Don’t wait until tomorrow, just do it now!”

I am also very thankful for the professors who pushed me along a research path through courses I have taken with them: Professor Richard Kaner, for inspiring me to pursue a career in inorganic and materials chemistry and Professor Anastassia Alexandrova, for introducing me to

x computational chemistry, which I fell in love with during the last few months of my time at

UCLA.

Finally, I would like to thank my family who, although may have been counterproductive towards my success at times, provided the love and support needed to ultimately succeed. My mother and father, John and Sheri, provided almost all of the financial support for my education and also set fantastic role models in terms of achieving a higher education and success. I am truly grateful to have the parents I have. Last, but most certainly not least, I would like to thank my darling Nikki for literally everything she has given me throughout the years, as well as for staying beside me despite all of the hardships we have been through together. Nikki not only prevented me from burning out by being the non-science balance in my life, but she also kept me sane and provided a motivation in the form of constantly reminding me of our future together.

I would also like to acknowledge the following:

Chapter three of this thesis contains computational data from Upton, B. M.; Matsumoto,

N. M.; Gipson, R. M.; Duhović S.; Lydon B. R.; Maynard, H. D.; Diaconescu, P. L. Inorganic

Chemistry Frontiers, manuscript submitted. Brianna Upton performed all of the synthetic and polymerization work, Nick Matsumoto provided molecular weight data through gel permeation chromatography, Ray Gipson pioneered the project, Selma Duhović provided spectral data, and

Professor Heather Maynard and Professor Paula Diaconescu were the principal investigators.

The Raymond and Dorothy Wilson Endowment summer research fellowship which funded my research in summer 2012.

The American Chemical Society for permission to reproduce the figure seen in Chapter 1, Figure

3 from Green, A. G.; Kiesz, M. D.; Oria, J. V.; Elliot, A. G.; Buchler, A. K.; Hohenberger, J.;

Meyer, K.; Zink, J. I.; Diaconescu, P. L. Inorg. Chem., 2013, 52, 5603-5610. et al.

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Chapter 1: Ferrocene Ligand Synthesis

1.1 Introduction

1.1.1 Background on ferrocene Since its structural discovery in 1951 by Woodward and Wilkinson,1 ferrocene has had a commanding presence in organometallic chemistry. Notable as the first sandwich complex, ferrocene has been the subject of myriad studies and potential applications including, but not limited to, structure and bonding,1 electrochemistry,2 medicinal chemistry,3 materials chemistry,4 and, most importantly for this thesis, an ancillary ligand platform.5

Figure 1. Structure of ferrocene determined by Woodward and Wilkinson

Ferrocene benefits from several innate properties: iron contains an η5- linkage to each cyclopentadiene ring,1 air stability,6 it is fairly inert due to its full 18 electron shell, and carbons of its cyclopentadienyl rings can be easily functionalized.7 In addition to these properties, iron easily undergoes a reversible one-electron oxidation to oxidize ferrocene to ferrocenium. In electrochemistry, ferrocene is generally used as an internal standard.2

1.1.2 Ferrocene ligands and their properties

As an ancillary ligand platform, ferrocene-based ligands form bimetallic chelates with other metals through donor moieties on its two cyclopentadienyl rings.7 These ligands often impart unique properties onto complexes.5 Special properties include electronic metal-metal communication between iron and metal centers, easily accessible reversible redox events, physical flexibility to accommodate metal centers, and steric hindrance. Ultimately, these properties cause a profound effect on catalysis at the metal center.

Figure 2. General framework of the Diaconescu group’s ferrocene-based ligands. D represents donor atoms bound to a metal center.

One of the goals of the Diaconescu group is to demonstrate these effects on various metals across the periodic table. For example, Green et al.8 showed through computational molecular orbital and natural bond orbital analysis that a weak iron-ruthenium bond with electron donation to ruthenium from iron takes place when 1,1’-ferrocenediamide (Figure 3) is used. The same publication also goes into the details of tilt and twist angles that are unique to the ferrocene backbone and illustrate the flexibility in its geometry in order to accommodate metal centers.

Figure 3. Iron-metal bond evidence in a 1,1’-ferrocenediamide metal complex through molecular orbital overlap. Downloaded with permission from reference 8.

These encumbering ligands also block access to metal centers from the backside while opening up binding pockets and leaving an open coordination sphere for reactivity on the front side.5

1.1.3 1-amino-1’-diphenylphosphinoferrocene

1,1’-Heterosubstitution of ferrocene is well known throughout the literature and creates new interesting electronic properties for ferrocene-based ligands.9 N,P ferrocene-based ligands, ligands that are functionalized by a nitrogen and a phosphorus, are common. However, the majority of these previously discovered ligands are neutral Lewis donors and are not 1,1’- substituted.10 As neutral Lewis donors, these ligands are great candidates for late transition metals such as palladium and platinum. Antagonistic to these ligands, most N,N ferrocene-based ligands, such as 1,1’-ferrocenediamide, are dianionic ligands and form complexes with most early11 and middle8 transition metals as well as lanthanides11 and actinides.5

The purpose of this project was to synthesize a monoanionic chelating ligand and then form complexes with group 3 metals. With only one precedent in the literature, 1-amino-1’-

9 diphenylphosphinoferrocene, (fc(NH2)(PPh2)), reported in 1998 by Butler and Quayle, became the project’s focus. Initial attempts in the Diaconescu lab to reproduce this synthesis were fruitless and it was not until we realized that the compound was highly air sensitive that any positive results began to surface. We have also formulated our own synthetic route that is different than the route reported in the original publication.

1.1 Results and Discussion

Figure 4. fc(TBSNH)(PPh2) synthetic scheme, 5 steps

i 1.2.1 Synthesis of fcBr(PPh2) and fcBr(P Pr2)

Figure 5. Chemical equation for fcBr(PR2).

Literature procedures were followed to convert ferrocene to dibromoferrocene.7 To synthesize a heterosubstituted compound, careful addition of one equivalent of n-BuLi to fcBr2, followed by an equivalent of chlorodiphenylphosphine, displaced one bromine for a phosphine group at the 1’ position. A literature procedure was followed for this step as well.12 However, fast kinetics of the lithiation resulted in a mixture of fcBr(PPh2),

1,1’-bis(diphenylphosphino)ferrocene (dppf), and unreacted fcBr2; this required us to optimize reaction conditions beyond what was originally reported. Increased dilution of reactants, longer reaction time at cold temperatures, and slower addition of n-BuLi helped control the reaction and prevented a mixture of products. THF was also removed under reduced pressure during the workup to prevent large emulsions normally present during separation. Column chromatography purified the crude product and presented three distinct bands for fcBr2, fcBr(PPh2), and dppf.

Crystallizing the product from DCM/hexanes yielded large brown/red crystals. Modifying the reaction conditions improved yields from 41% to 71%, higher than originally published. Proton

NMR spectroscopy (Figure 9) confirmed successful synthesis of the product by evidence of four distinct ferrocene peaks at δ = 4.00, 4.18, 4.34, and 4.44 ppm; it shows, however, that some residual dppf is present within the sample with peaks between δ = 4.00 and 4.15 ppm. 31P NMR

5 spectroscopy (Figure 10) displays a single large peak at δ = -17.70 ppm and a small impurity at -

16.51 ppm.

i fcBr(P Pr2) was synthesized to obtain a more electron-donating phosphine moiety to form stronger bonds to electron-deficient group 3 metals. It was also synthesized from a modified literature procedure.13 Aside from lower temperatures, longer reaction time, and slower addition applied from the reaction of the diphenylphosphine derivative, additional changes to the published procedure were required. The original literature procedure states that the product was purified using column chromatography with a 10:1 petroleum ether : diethyl ether solvent system, but it was found that 100:1 petroleum ether : diethyl ether was needed to cleanly obtain the desired product. This compound was obtained in a 41% yield and is not air stable, unlike

i 1 fcBr(PPh2). Successful synthesis of fcBr(P Pr2) was confirmed by H NMR spectroscopy (Figure

11) with four ferrocene proton chemical shifts at δ = 3.84, 4.07, 4.12, and 4.27 ppm and the iso- propyl shifts at δ = 1.02 and 1.79 ppm. 31P NMR spectroscopy (Figure 12) shows a single peak at

δ = -1.30 ppm and a slight impurity at δ = -0.41 ppm likely from the disubstituted phosphine byproduct.

1.2.2 Synthesis of fc(NH2)(PPH2)

Figure 6. Chemical equation for fc(NH2)(PR2)

The main focus of this project was optimizing the synthesis of fc(NH2)(PPh2) seen in

Figure 4, because even when air sensitive technique was employed we obtained poor yields.

This was most likely due to an inadequate sparging procedure used to degas large volumes of aqueous HCl and NaOH used during the workup. Although the α-azidostyrene synthetic route formulated by former graduate student Dr. Colin Carver provides better yields than the literature preparation,9 it also has caveats. The azide reagent must be occasionally purified through alumina before use because it decomposes at -26°C over time and is sensitive to light.

Decomposition can be observed visually by color change from pale yellow to brown/dark yellow. After addition of the azide to the lithiated compound, a highly light sensitive adduct immediately forms. If exposed to light, this adduct decomposes resulting in a significant decrease in yield. Another restraint of this reaction is scale. Performing this reaction with as little as 165 mg of fcBr(PPh2) causes problems due to the large volume of dry and degassed Et2O required for the workup. After optimizing reaction conditions, a 41% yield, improved from the literature reported 38% yield, was achieved. Unfortunately, these results were not always reproducible and reactions often produced yields lower than 20%. Proof of synthesizing fc(NH2)(PPh2) is evident by proton and phosphorus NMR spectra as well as elemental analysis.

The 1H NMR spectrum (Figure 13) reveals a peak from both amino protons at δ = 2.30 ppm and disappearance of the dppf impurity from the previous step. Although we observed a significant shift in the 31P NMR spectrum (Figure 14) from the original publication, δ = -16.88 ppm compared to δ = -17.57 ppm, only a single peak is present. The 1H NMR spectrum reveals all necessary peaks at the proper integrations; shifts from amino, ferrocene, and aryl protons are all present. Any excess impurities evident in the 1H NMR spectrum can be attributed to solvent with the exception of the δ = 4.2 ppm chemical shift. This shift is speculated to be a

i phosphineoxide impurity. Following the same general procedure, synthesis of fc(NH2)(P Pr2) was unsuccessful and resulted in clear decomposition evident in the 1H and 31P NMR spectra.

1.2.3 Synthesis of fc(TBSNH)(PPH2)

Figure 7. Chemical equation for fc(TBSNH)(PPh2)

After the successful synthesis of fc(TBSNH)(NH2), a general procedure to add a tert- butyldimethylsilyl moiety to an amine14 was performed. Triethylamine and tert- butyldimethylsilyl chloride were used to convert fc(NH2)(PPh2) to fc(TBSNH)(PPh2) in an 89% yield. The product was characterized by 1H (Figure 15), 31P (Figure 16), and 13C (Figure 17)

NMR spectroscopy as well as elemental analysis. The 1H NMR spectrum shows characteristic

8 tert-butyl and methyl peaks at δ = 0.84 and 0.05 ppm respectively. A peak shift from fc(NH2)(PPH2) and a decrease of peak area to 1 for the amino peak at δ = 1.84 ppm also suggests successful conversion of the product. The 31P NMR spectrum shows a single peak shifted slightly from the reactant from δ = -16.88 to -16.64 ppm.

1.2.4 Attempts to Form Metal Complexes

After synthesizing fc(TBSNH)(PPh2), we looked towards forming complexes with group

3 metals and lanthanides. Group 3 metals exclusively possess a +3 oxidation state with few exceptions. Using this knowledge, we planned to isolate a metal dialkyl species; for group 3 metals, this can only be achieved with monoanionic ligands. To synthesize group 3 metal complexes, five metal precursors were prepared. These compounds include:

Sc(CH2SiMe3)3(THF)2, Lu(CH2Xy-3,5)3(THF)2, Lu(CH2SiMe3)(THF2), and Sc(CH2Xy-

3,5)(THF)2. A salt metathesis approach was also taken after synthesizing fc(TBSNK)(PPh2), a potassium salt, and reacting it with YCl3. Although proton NMR spectroscopy could not definitively confirm the existence of fc(TBSNK)(PPH2) due to its insolubility in d6-benzene, it did provide a toluene peak from proton extraction by benzylpotassium. After filtering the insoluble solid through wet Celite, fc(TBSNH)(PPh2) was recovered. Unfortunately, no group 3 metal complexes could be cleanly isolated.

For all coordination reactions attempted, 1H NMR spectra revealed significant shifts from both reactants, and in some cases appeared as if conversion had occurred. 31P NMR spectra confirmed that either these complexes did not form at all or a nitrogen-metal bond formed while a phosphorus-metal bond was not formed. This is evident from multiple small chemical shifts

9 from fc(TBSNH)(PPh2), none of which correlated with a phosphorus-metal bond. An exception was observed when reacting fc(TBSNH)(PPh2) with scandium tris-3,5-dimethylbenzyl which showed multiple 31P NMR chemical shifts near δ = 172 ppm within the spectrum. Despite this result, no complex with a single 31P chemical shift could be isolated. We concluded that hard acid properties of group 3 metals were incompatible with soft base properties of phosphorus on fc(TBSNH)(PPh2). In future experiments, reactions with fc(TBSNH)(PPh2) and mid-late transition metals are suggested.

1.3 Conclusions

fc(TBSNH)(PPh2) was successfully synthesized in high yields and fully characterized. fc(NH2)(PPh2) has been successfully synthesized by a novel synthetic route and has been characterized by 1H NMR spectroscopy, 31P NMR spectroscopy, and elemental analysis. Yields for the fc(NH2)(PPh2) reaction have improved to 41% using air free methods, however, this result was not consistently reproducible. Group 3 metal complexes could not be synthesized using fc(TBSNH)(PPh2). Coordination to mid to late transition metals is suggested for future work.

1.4 Experimental section

1.4.1 General Considerations

All experiments were performed under a dry nitrogen atmosphere in either an MBraun inert-gas glovebox or using a Schlenk line unless noted otherwise. Solvents were purified using

10 a two-column solid-state purification system by the method of Grubbs.15 NMR solvents were obtained from Cambridge Isotope Laboratories, degassed, and then stored over activated molecular sieves before use. 1H and 31P NMR spectra were acquired using a Bruker AV300

NMR spectrometer at room temperature. 1H NMR chemical shifts were referenced with respect to solvent peaks at 7.16 ppm for C6D6, or at 7.26 ppm for CDCl3. Scandium, yttrium, and lutetium oxides were purchased from Stanford Materials Corp. (Aliso Viejo, CA) and used as received. 1,1’-Dibromoferrocene,7 α-azidostyrene,16 PiPrCl,17 benzyl potassium,18

19 20 21 Sc(CH2SiMe3)(THF2), Lu(CH2Xy-3,5)3(THF)2, Lu(CH2SiMe3)(THF)2, and Sc(CH2Xy-

22 3,5)(THF)2, were prepared following literature procedures. TMEDA, 1,1,2,2- tetrabromoethane, and triethylamine were purchased and distilled under nitrogen prior to use.

Other chemicals were used as received. CHN analyses were performed in-house on an Exeter

Analytical CE-440 Elemental Analyzer.

1.4.2 Preparation of fcBr(PPh2)

This compound was prepared using a modified literature procedure.12 In the glovebox, fcBr2 (2.5 g, 7.27 mmol) was dissolved in THF and cooled to -78°C in a round bottom flask equipped with a stir bar. n-BuLi (2.91 mL, 7.27 mmol, 2.5M, 1eq.) dissolved in THF (2 mL) was added to the stirring solution dropwise over 10 minutes. The reaction was allowed to stir for 10 minutes at -78°C before diphenylphosphine chloride (1.61 g, 7.27 mmol, 1 eq) was added slowly dropwise. After the reaction had stirred for an additional 15 minutes at -78°C, it was gradually warmed to room temperature and allowed to stir for an additional 90 minutes. The reaction was then removed from the glovebox and carefully quenched with H2O. THF was removed under

11 reduced pressure before aqueous extraction using DCM (10 mL fractions until aqueous layer is colorless) was performed. The combined organic phase was dried over MgSO4 before removing

DCM under reduced pressure. The compound was purified by column chromatography 4:1 Pet

1 Ether:DCM and then recrystallized from DCM/hexanes. Yield 71%. H NMR (benzene-d6, 300

MHz, 25C): δ 4.00 (d, 2H, Cp-H), 4.18 (d, 2H, Cp-H), 4.34 (d, 2H, Cp-H), 4.44 (d, 2H, Cp-H),

7.34 (m, 10H, PArH)

i 1.4.3 Preparation of fcBr(P Pr2)

13 This compound was prepared using a modified literature procedure. fcBr2 (280 mg,

0.813 mmol) was added to a round bottom flask with a stirbar and dissolved in THF (25 mL).

The flask was cooled to -78°C before adding n-BuLi (0.33 mL, 2.5 M, 0.813 mmol), dissolved in

THF (1 mL), dropwise. The reaction was allowed to stir for 15 minutes before iso- propylphosphine chloride (124 mg, 0.813 mmol), dissolved in THF (2 mL), was added dropwise over several minutes. The reaction continued to stir at -78°C for 20 minutes and then another 90 minutes at room temperature. The reaction was then removed from the glovebox and then quenched with H2O (25 mL). THF was removed under reduced pressure. The solution was extracted with DCM (1 mL fractions) until the aqueous phase was colorless. The combined organic layer was dried over MgSO4 and solvent was removed in vacuo resulting in an orange- brown oil. The oil was purified via column chromatography (100:1, Petroleum ether:ether) and

1 then set to crystallize from Et2O/hexanes. Yield 41%. H NMR (benzene-d6, 300 MHz, 25C): δ

1.04 (m, 12H, PCHCH3), 1.79 (qd, 2H, PCH(CH3)2), 3.84 (d, 2H, Cp-H), 4.07 (d, 2H, Cp-H),

31 4.12 (d, 2H, Cp-H), 4.27 (d, 2H, Cp-H). P NMR (benzene-d6, 300 MHz, 25C): δ -1.295 (Cp-P- i Pr2).

1.4.4 Preparation of fc(NH2)(PPh2)

Inside of the glovebox, fcBr(PPh2) (165 mg, 0.369 mmol) was dissolved in THF and cooled to -78°C in a Schlenk flask equipped with a stir bar. n-BuLi (0.15 mL, 0.39 mmol, 2.5 M in hexanes) was added via syringe and the solution was allowed to stir cold for 10 minutes and then at room temperature for 15 minutes. The reaction flask was then cooled again to -78°C for

20 minutes. In the dark, α-azidostyrene (66 mg, 0.455 mmol), dissolved in THF (2 mL), was added slowly dropwise. The reaction was allowed to stir cold for 20 minutes before stirring for

45 minutes at room temperature. The reaction flask was then removed from the glovebox to the

Schlenk line and kept in the dark. Nitrogen-purged aqueous HCl (12 mL, 3 M) was added slowly to the reaction resulting in the evolution of nitrogen gas. The solution was allowed to stir for 10 minutes before being reintroduced to the light. The aqueous phase was washed with dry nitrogen-sparged Et2O (12 mL fractions) until the organic phase becomes colorless. Upon addition of nitrogen-purged aqueous NaOH (24 mL, 3M) the orange product transfers to the organic phase. The aqueous organic phase was then extracted with Et2O (12 mL) fractions onto

MgSO4 in a nitrogen-purged container to dry. After removal of solvent in vacuo, the Schlenk flask was brought back into the glovebox and filtered with Et2O through a frit. The filtrate was then dried yielding the crude product. The crude product was purified by filtration through an alumina plug in THF followed by crystallization in toluene/hexanes yielding pure fc(NH2)(PPh2).

Yield: 41%. 1H NMR (chloroform-d, 300 MHz, 25C): δ 2.30 (s, 2H, NH), 3.77 (d, 2H, cp-H),

3.89 (d, 2H, cp-H), 4.01 (d, 2H, cp-H), 4.34 (d, 2H, cp-H), 7.32 (m, 4H, P-ArH), 7.41 (m, 6H, P-

31 ArH). P NMR (chloroform-d, 300 MHz, 25C): δ -16.88 (PPh2). Anal. Calcd for C22H20FeNP:

C, 68.59; H, 5.23; N, 3.64. Found: C, 68.62; H, 4.86; N, 3.75.

1.4.5 Preparation of fc(TBSNH)(PPh2)

In the glovebox, fc(NH2)(PPh2) (39 mg, 0.101 mmol) was dissolved in a minimal amount of dichloromethane and then frozen at -196°C. tert-Butylchlorodimethylsilane (18.2 mg, 0.124 mmol, 1.23 eq) was dissolved in triethylamine (11.23 mg, 0.111 mmol, 1.1 eq) and added slowly on top of the previously frozen solution. The reaction was allowed to warm to room temperature and stir overnight. The following day, volatiles were removed in vacuo and the resulting crude product was filtered through Celite in hexanes. Crystallization from hexanes yielded pure

1 fc(TBSNH)(PPh2). Yield: 89%. H NMR (benzene-d6, 300 MHz, 25C): δ 0.05 (s, 6H, SiMeH),

0.84 (s, 9H, t-BuHSi), 1.84 (s, 1H, NH), 3.80 (m, 4H, cp-H), 4.09 (d, 2H, cp-H), 4.22 (d, 2H, cp-

13 H), 7.06 (m, 6H, P-ArH), 7.57 (m, 6H, cp-H). C NMR (benzene-d6, 300 MHz, 25C): δ -4.56,

17.80, 26.15, 60.02, 64.33, 72.31, 73.73, 73.93, 108.20, 133.60, 133.86, 140.15, 140.31. 31P

NMR (benzene-d6, 300 MHz, 25C): δ -16.64 (PPh2). Anal. Calcd for C28H34FeNPSi: C, 67.33;

H, 6.60; N, 2.62. Found: C, 67.58; H, 6.60; N, 2.62.

1.5 Supplementary Material

1 Figure 8. H NMR spectrum of fcBr(PPH2) (CDCl3)

31 Figure 9. P NMR spectrum of fcBr(PPh2) (CDCl3)

1 i Figure 10. H NMR of fcBr(P Pr2) (CDCl3)

31 i Figure. 11. P NMR spectrum of fcBr(P Pr2) (CDCl3)

1 Figure 12. H NMR spectrum of fc(NH2)(PPh2) (CDCl3)

31 Figure 13. P NMR of fc(NH2)(PPh2) (CDCl3)

1 Figure 14. H NMR spectrum of fc(TBSNH)(PPH2) (C6D6)

31 Figure 15. P NMR spectrum of fc(TBSNH)(PPH2) (C6D6)

13 Figure 16. C NMR spectrum of fc(TBSNH)(PPH2) (C6D6)

1.6 References

(1) Wilkinson, G.; Rosenblum, M.; Whiting, M. C.; Woodward, R. B. J. Am. Chem. Soc.,

1952, 74 (8), 2125–2126.

(2) Gagne, R. R.; Koval, C. A.; Lisensky, G. C. Inorg. Chem., 1980, 19, 2854-2855.

(3) Top, S. et al. Chem. Eur. J., 2003, 9(21), 5223-5236.

(4) Conroy, D.; Moisala, A; Cardoso, S.; Windle, A.; Davidson, J. Chem. Eng. Sci., 2010,

65(10), 2965-2977.

(5) Diaconescu, P. L. Acc. Chem. Res., 2010, 43(10) 1352-1363.

(6) Kealy, T. J., and Pauson, P. L. Nature, 1951, 168, 1039.

(7) Shafir, A.; Power, P.; Whitener, G. D.; Arnold, J. Organometallics, 2000, 19, 3978-3982.

(8) Green, A. G.; Kiesz, M. D.; Oria, J. V.; Elliot, A. G.; Buchler, A. K.; Hohenberger, J.;

Meyer, K.; Zink, J. I.; Diaconescu, P. L. Inorg. Chem., 2013, 52, 5603-5610.

(9) Butler, I. R.; Quayle, S. C. J. Organomet. Chem., 1998, 552, 63-68.

(10) Atkinson, R. C. J.; Gibson, V. C.; Long, N. J. Chem. Soc. Rev., 2004, 22, 313-328.

(11) Williams, B. N.; Benitez, D.; Miller, K. L.; Tkatchouk, E.; Goddard, W. A. III;

Diaconescu, P. L. J. Am. Chem. Soc., 2011, 133(13), 4680-4683.

(12) Lai, L.-L.; Dong, T.-Y., J. Chem. Soc., Chem. Commun., 1994, 1078.

(13) Butler, I. R.; Davies, R. L. Synthesis, 1996, 11, 1350-1354.

(14) Shafir, A.; Power, M. P.; Whitener, G. D.; Arnold, J. Organometallics, 2001, 20(7),

1365-1369.

(15) Pangborn, A. B.; Giardello, M. A.; Grubbs, R. H.; Rosen, R. K.; Timmers, F. J.

Organometallics, 1996, 15, 518–1520.

(16) Smolinsky, G. J. Org. Chem., 1962, 27(10), 3557–3559.

(17) Voskuil, W.; Arens, J. F. Organic Syntheses, Coll., 1973, 5, 211.

(18) Gilman, H.; Pacevitz, H. A.; Ogden, B. J. Am. Chem. Soc., 1940, 62(6), 1514-1520.

(19) Lappert, M. F.; Pearce, R. J. Chem. Soc., Chem. Commun., 1973, 126.

(20) Carver, C. T.; Benitez, D.; Miller, K. L.; Williams, B. N.; Tkatchouk, E.; Goddard, W.

A.; Diaconescu, P. L. J. Am. Chem. Soc., 2009,131, 10269-10278.

(21) Arndt, S.; Voth, P.; Spaniol, T. P.; Okuda, J. Organometallics 2000, 19, 4960.

(22) Carver, C. T.; Monreal, M. J.; Diaconescu, P. L. Organometallics, 2008, 27(3), 363-370.

Chapter 2: Redox-Active Ferrocene Ligands and Applications in Hydroamination

2.1 Introduction

2.1.1 Hydroamination Background

Synthetic products from imines, enamines, and substituted amines are important for numerous natural product synthetic intermediates,1 pharmaceutical,2 industrial, and agricultural applications. Hydroamination, the formal addition of an N-H bond across a C-C multiple bond, is an efficient means to these products.1

Figure 1. General examples of hydroamination reactions.

Substitution of amines can be accomplished by various organic synthetic methods such as nucleophilic substitution, amination, and reductive amination. However, hydroamination offers an improved atom economical route to these syntheses.1 Although hydroamination is thermodynamically favorable, these reactions often require high temperatures and use of a catalyst due to high activation barriers.1 Group 4 metals and lanthanides are most commonly used as catalysts for hydroamination, however, metals across the entire periodic table have been

21 observed to catalyze these reactions as well.3-5 Hydroamination can occur both inter- and intra- molecularly depending on which substrates and catalyst are used.

Use of group 4 metals as catalysts for intramolecular hydroamination has been extensively studied in the literature. Zirconium catalysts for these reactions often exhibit selectivity dependent on the oxidation state of zirconium and what type of aminoalkene is used.

With few exceptions, neutral zirconium catalysts exclusively catalyze primary aminoalkenes.6-10

Cationic zirconium catalysts have displayed either no selectivity, where they catalyze both primary and secondary aminoalkenes,11,12 or they selectively catalyze only secondary aminoalkenes.12,13 Selective hydroamination of primary or secondary aminoalkenes in situ with one catalyst has not previously been achieved.

Figure 2: General example of intramolecular hydroamination reactions with neutral zirconium catalysts.

2.1.2 Redox Active Ligands

To develop, control, and utilize stepwise catalytic processes, such as the synthesis of ring-opened block co-polymers, a reversible trigger is required.14 A reversible trigger currently under heavy research is redox-active ligands. Changing oxidation states of metallocene-based

22 ligands has shown to modulate reactivity in catalytic systems.15 Ferrocene-based ligands are particularly interesting due to their mild oxidation potentials and stability in their oxidized ferrocenium forms.

Figure 3. General example of redox activity for ferrocene-based ligands.

Salfen, the Schiff base ferrocene-analogue of salen,16 was synthesized by Arnold and coworkers17 and has been used in complexes with cerium for catalytic ring-opening polymerization of lactides.15 Recent efforts led by Dr. Xinke Wang in the Diaconescu laboratory have expanded this ligand platform through development of four analogues (Figure 4).18 These tetradentate ligands were synthesized to observe effects that redox events have on catalytic reactivity when they are coordinated to group 4 metals. In the present study, we have demonstrated a proof of concept using redox-switchable ligands as a trigger for selective hydroamination.

Figure 4. Evolution of H2(salfan) and H2(thiolfan)

2.2 Results and Discussion

This study reports preliminary results for selective intramolecular hydroamination using ferrocene-based redox-active zirconium catalysts.

Figure 5: Redox-switchable zirconium catalysts used for intramolecular hydroamination study.

2.2.1 Phase One of Redox-switchable Selective Hydroamination

First, each neutral catalyst in Figure 5 was reacted with the primary amine substrate (1) in

Figure 2. The neutral catalyst was then tested for activity with the secondary amine substrate (2).

Following trends from previous literature, all three neutral zirconium catalysts catalyzed the cyclization reaction with substrate (1) at 10 mol% with heating over 24 hours. This is evident from 1H NMR spectra (Figure 8) in timed experiments. Two peaks begin to develop at δ = 0.85 and 1 ppm indicating conversion of the cyclized product and therefore activity of the catalyst.17

2 (thiolfan )ZrBn2 and (salfen)ZrBn2 are both active catalysts for cyclizing (1) while (salfan)ZrBn2 demonstrated activity but did not catalyze the reaction to completion. It is possible that lower activity observed for (salfan)ZrBn2 can be attributed to thermal decomposition of the complex which was evident at 24 hours through proton NMR spectroscopy.

2 After reacting the catalysts with (2), it was found that (salfan)ZrBn2 and (thiolfan )ZrBn2 experienced no activity (Figure 9), correlating with literature. However, (salfen)ZrBn2 converted a portion of the substrate. Catalytic activity for (salfen)ZrBn2 was evident by formation of new peaks at δ = 2.5 and 2.6 ppm in the 1H NMR spectrum.19 Lack of activity seen with

(salfan)ZrBn2 with (1), and low activity of (salfen)ZrBn2 with (2), made them undesirable as

2 potential selective catalysts for this study. Only (thiolfan )ZrBn2, which catalyzed (1) and not

(2), was used for the second phase of the study. Although no cyclization occurred while reacting

2 (thiolfan )ZrBn2 and (2), a toluene chemical shift was observed due to the displaced benzyl groups from zirconium. This indicated that ligand exchange took place, but cyclization did not occur.

2.2.2 Phase Two of Redox-switchable Selective Hydroamination

The goal of the study’s second phase was to repeat phase 1 but with oxidized catalysts.

F 2 2+ 3+ Reacting the mild oxidant, AcFcBAr , with (thiolfan )ZrBn2 oxidized Fe to Fe selectively over the Zr center. We hypothesized that cationic ferrocenium-zirconium complexes will catalyze (2) but not (1), switching the selectivity from phase 1. This would show selectivity between primary and secondary alkeneamines based on a redox-switchable trigger.

2 To test this hypothesis, (2) was first added to (thiolfan )ZrBn2 followed by one equivalent of AcFcBArF. The reaction was monitored by 1H NMR spectroscopy and heated to 100°C for 24 hours. Conversion of (2) to the cyclized product was observed to be near completion when obtaining the first NMR spectrum at 0 hours and room temperature. This indicated an active catalyst. Unfortunately, an alkene isomerization byproduct was also speculated to be generated in the reaction based on chemical shifts in the 1H NMR spectrum at δ = 2.69 ppm (Figure 17).

This peak was not characteristic of the cyclized product. To avoid the byproduct, future experiments should be more carefully controlled through slower addition of each reagent and a longer reaction time interval at room temperature.

2 To confirm that oxidized (thiolfan )ZrBn2 catalyzed (2) and not the oxidant, a control experiment was performed. Under identical reaction conditions, without the catalyst, (2) was added to AcFcBArF and was monitored over 24 hours by 1H NMR spectroscopy (Figure 18).

Although no reactivity was seen in the first four hours of the experiment, a small amount of the cyclized product was observed by 1H NMR spectroscopy after 24 hours at 100°C. Oxidized

2 (thiolfan )ZrBn2 was confirmed to be the catalyst due to its reactivity observed at zero hours and room temperature.

Lack of time and catalyst prevented the final cyclization reaction with (1) and oxidized

2 (thiolfan )ZrBn2 from being performed. It is my hope that future Diaconescu group members can finish the project, find other suitable catalysts, and perform mechanistic studies to explain the reactivity. Based on these preliminary results, redox-switchable ferrocene-based zirconium catalysts show promise in applications for cascade synthesis of cyclic amines. In a polyolefin polyamine, a primary amine could be selectively cyclized with a neutral catalyst before addition of a mild oxidant that would then cause cyclization of secondary amines in situ.

2 2.2.3 Synthesis of (thiolfan )Zr(NEt2)2

2 Figure 6. Chemical equation for (thiolfan )Zr(NEt2)2

2 1 The reaction of H2(thiolfan ) with Zr(NEt2)4 was monitored by H NMR spectroscopy and fully converted at room temperature. To examine its redox capabilities, one equivalent of

AcFcBArF was added resulting in an instant color change to dark blue/green. The 1H NMR spectrum reveals residual complex peaks after magnifying the baseline, evident of a paramagnetic complex. Unfortunately, addition of one equivalent of cobaltocene did not

2 regenerate (thiolfan )Zr(NEt2)2 and resulted in decomposition. A milder reductant or colder temperatures may be required to reduce this complex.

2.3 Conclusions

Intramolecular hydroamination has been performed with three redox-active catalysts to

2 screen for selective reactivity between primary and secondary amines. Only (thiolfan )ZrBn2 catalyzed reactions as predicted by literature in phase 1 of the study and was exclusively used for

2 phase 2. After oxidation, (thiolfan )ZrBn2 cyclized a secondary alkeneamine, however, an alkene isomerization byproduct was also observed. A control experiment without a catalyst

2 2 confirmed that oxidized (thiolfan )ZrBn2 catalyzed the reaction. (thiolfan )Zr(NEt2)2 was synthesized cleanly and redox properties were examined. Although oxidation of the complex was successful, subsequent reduction resulted in decomposition.

2.4 Experimental section

2.4.1 General Considerations

All experiments were performed under a dry nitrogen atmosphere in either an MBraun inert-gas glovebox or using a Schlenk line unless noted otherwise. Solvents were purified using a two-column solid-state purification system by the method of Grubbs.20 NMR solvents were obtained from Cambridge Isotope Laboratories, degassed, and then stored over activated molecular sieves before use. 1H NMR spectra were acquired using a Bruker AV300 NMR spectrometer at room temperature. 1H NMR chemical shifts were referenced with respect to the

21 7 18 solvent peak at 7.16 ppm for C6D6. Substrate (1), substrate (2), (salfan)ZrBn2,

2 18 17 18 F 18 (thiolfan )ZrBn2, (salfen)ZrBn2, H2(thiolfan), and AcFcBAr , were prepared by literature procedures. Other chemicals were used as received.

2.4.2 General Procedure for Hydroamination Reactions with Neutral Catalysts

Metal catalyst (0.01 mmol, 10 mol%) was dissolved in C6D6 and added to a J-Young tube. Hydroamination substrate (0.1 mmol) was also dissolved in C6D6 and added to the J-

Young tube. The tube was then sealed and analyzed for a 0-hour 1H NMR spectrum before being heated to 100°C. Reactions were monitored for 3-4 hours before being left to heat overnight and were analyzed one more time near 24 hours.

2.4.3 General Procedure for Hydroamination Reactions with Oxidized Catalysts

Metal catalyst (0.01 mmol, 10 mol%) was dissolved in C6D6 and added to a J-Young tube. (AcFcBArF) (10.91 mg, 0.01 mmol, 10 mol%) was then added to the J-Young tube leading to a color change from orange to dark green/blue. Hydroamination substrate (0.1 mmol) was also dissolved in C6D6 and added to the J-Young tube. The tube was then sealed and analyzed for a

0-hour 1H NMR spectrum before being heated to 100°C. Reactions were monitored for 3-4 hours before being left to heat overnight and were analyzed one more time near 24 hours.

2 2.4.4 Preparation of (thiolfan )Zr(NEt2)2

2 H2(thiolfan ) (6.59 mg, 0.01 mmol) was dissolved in C6D6 and was added to tetrakis(diethylamido) zirconium(IV) (2.68 mg, 0.01 mmol), also dissolved in C6D6, in a JYoung

29 tube at room temperature. The reaction formed a clear orange solution and was monitored by 1H

2 1 NMR spectroscopy cleanly yielding (thiolfan )Zr(NEt2)2. H NMR (benzene-d6, 300 MHz, 25C):

δ 0.99 (t, 12H, NCH3), 1.23 (s, 18H, Ar(t-BuH)), 1.79 (s, 18H, Ar(t-BuH), 2.48 (q, 8H, N-CH2),

3.71 (broad, 8H, Cp-H), 7.60 (d,d, 4H, Ar-H).

2 2.4.5 Oxidation and Reduction of (thiolfan )Zr(NEt2)2

Acetylferrocenium tetrakis-3,5-bis(trifluoromethyl)phenylborate (AcFcBArF) (10.9 mg,

2 0.01 mmol, 1eq) was added in situ to the (thiolfan )Zr(NEt2)2 reaction. The solution changed colors from orange to dark green and was examined by 1H NMR spectroscopy before cobaltocene was added (1.9 mg, 0.01 mmol, 1 eq) in situ. Addition of cobaltocene resulted in no change in the 1H NMR spectrum.

2.5 Supplementary Material

1 2 Figure 7. H NMR spectrum of (thiolfan )Zr(NEt2)2 (C6D6).

1 2 Figure 8. H NMR spectrum of time-monitored experiment. Neutral (thiolfan )ZrBn2 with primary hydroamination substrate. (C6D6).

1 2 Figure 9. H NMR spectrum of time-monitored experiment. Neutral (thiolfan )ZrBn2 with secondary hydroamination substrate. (C6D6).

1 2 Figure 10. H NMR spectrum of time-monitored experiment. Oxidized (thiolfan )ZrBn2 with secondary hydroamination substrate. (C6D6).

Figure 11. 1H NMR spectrum of time-monitored control experiment. Secondary hydroamination

F substrate plus AcFcBAr , no catalyst (C6D6).

2.6 References

(1) Seayad, J.; Tillack, A.; Hartung, C. G.; Beller, M. Adv. Synth. Catal., 2002, 344, 795-813.

(2) Li, S.; Huang, K.; Zhang, J.; Wu, W.; Zhang, X. Org. Lett., 2013, 15(5), 1036-1039.

(3) Hong, S.; Marks, T. J. Acc. Chem. Res., 2004, 37(9), 673-686.

(4) Hultzch, K. C. Adv. Syn. Cat., 2005, 347(2+3), 367-391.

(5) Neal, S. R.; Ellern, A.; Sadow, A. D. J. Organomet. Chem., 2010, 696(1), 228-234.

(6) Majumder, S.; Odom, A. L. Organometallics, 2008, 27, 1174.

(7) Stubbert, B. D.; Marks, T. J. J. Am. Chem. Soc., 2007,129, 6149.

(8) Meuller, C.; Saak, W.; Doye, S. Eur. J. Org. Chem., 2008, 2731.

(9) Leitch, D. C.; Payne, P. R.; Dunbar, C. R.; Schafer, L. L. J. Am.Chem. Soc., 2009, 131,

18246.

(10) Hu, Y.-C.; Liang, C.-F.; Tsai, J.-H.; Yap, G. P. A.; Chang, Y.-T.; Ong, T.-G.

Organometallics, 2010, 29, 3357.

(11) Wang, X.; Chen, Z.; Sun, X.-L.; Tang, Y.; Xie, Z. Org. Lett., 2011, 13(18), 4758-4761.

(12) Gribkov, D. V.; Hultzsch, K. C. Angew. Chem. Int. Ed., 2004, 43, 5542-5546.

(13) Knight, P. D.; Munslow, I.; O’Shaughnessy, P. N.; Scott, P. Chem. Commun., 2004, 894.

(14) Luca, O. R.; Crabtree, R. H. Chem Soc Rev., 2013, 42, 1440-1459.

(15) Broderick, E. M.; Guo, N.; Vogel, S. C.; Xu, C.; Sutter, J.; Miller, J. T.; Meyer, K.;

Mehrkhodavandi, P.; Diaconescu. P. L. J. Am. Chem. Soc., 2011, 133, 9278-9281.

(16) Pfeiffer, P.; Breith, E.; Lubbe, E.; Tsumaki, T. European Journal of Chemistry, 1933,

503(1), 84-130.

(17) Shafir, A.; Fiedler, D.; Arnold, J. J. Chem. Soc., Dalton Trans., 2002, 4, 550-560

(18) Wang, X.; Diaconescu, P. L. et. al., manuscript in preparation.

(19) Arrowsmith, M.; Crimmin, M. R.; Barrett, A. G. M.; Hill, M. S.; Kociok-Kohn, G.;

Procopiou, P. A. Organometallics, 2011, 30(6), 1493–1506.

(20) Pangborn, A. B.; Giardello, M. A.; Grubbs, R. H.; Rosen, R. K.; Timmers, F. J.

Organometallics, 1996, 15, 518–1520.

(21) Hong, S.; Tian, S.; Metz, M. V.; Marks, T. J. J. Am. Chem. Soc., 2003, 125, 14768-

14783.

Chapter 3: Computational Study of Ferrocene-functionalized Biodegradable Polymers

3.1 Introduction

3.1.1 Background on Ferrocene in Polymers and Materials

Chapter one of this thesis mentioned that ferrocene has been used in applications for materials chemistry ranging from pharmaceuticals, fuel additives, and catalysis. Past developments in ferrocene chemistry have also led to the discovery of polymers made up of monomers functionalized with ferrocene. A key example of these polymers comes from

Manners and coworkers with polyferrocenylsilanes.1 These ferrocene-based polymers have been used for nanostructure applications and other material uses such as photoconductivity and photoxidation of thin films.2,3 An important property nearly absent in the literature for ferrocene-containing polymers is biodegradability.4 Ferrocene, which has already been used in drugs such as ferrocifen,5 a tomoxifen analogue, could potentially be used for additional medicinal applications if biodegradable polymers became readily available.

3.1.2 Overview of Current Project in Biodegradable Polymers

A current project in the Diaconescu lab involves the synthesis of biodegradable polymers by ring-opening polymerization of cyclic carbonate and δ-valerolactone monomers containing ferrocenyl groups.6 To polymerize the monomers in Figure 1 a catalyst is needed. Lewis acidic

i i metal complexes such as Ti(O Pr)4 and Al(O Pr)4 that are known to successfully ring-open carbonates and δ-valerolactones were used as catalysts without success.7-10 Instead, an

35 organocatalytic system consisting of benzyl alcohol (BnOH), 1,8-diazabicycloundec-7-ene

(DBU), and 1-(3,5-bis(trifluoromethyl)phenyl)-3-cyclohexylthiourea (thiourea) was used. This system has been seen to ring-open cyclic carbonates and δ-valerolactones in previous literature.11

Figure 1. Pre-optimized ring-closed monomers used in polymerization and computational study

Experimental results carried out by Brianna Upton showed that only the cyclic carbonate monomers (M1-M6) could be polymerized while the δ-valerolactone monomers (M7-M9) could not.6 This was true even after heating for 24 hours with the catalytic system. To help understand

36 these experimental results, a computational study was performed to calculate if the initial ring- opening reaction for each monomer is thermodynamically favorable. The results of this study should suggest whether the δ-valerolactone ring-opening reactions are thermodynamically or kinetically unfavorable.

3.2 Results and Discussion

Calculations were performed to obtain the Gibbs free energy of reaction for the initial ring-opening step for each monomer. DFT calculations were performed using the B3LYP12 density functional and the 6-311+G* basis set in Gaussian 09.13 First, geometries of ring-opened monomers (ROM), ring-closed monomers (RCM), and benzyl alcohol (BnOH), were optimized.

Following optimization, vibrational frequency calculations were performed to confirm the structure was at a minima on the potential energy surface by confirming the absence of imaginary frequencies and to collect thermodynamic data for enthalpy and Gibbs free energy.

The Gibbs free energy of reaction and the enthalpy of reaction are summarized for each monomer in Table 1. Calculations are based off of equations 1-3.

ΔH = ΣHproducts - ΣHreactants 2

ΔG = ΣGproducts - ΣGreactants 3

B3LYP/ ΔH ΔG 6-311+G* (kcal/mol) (kcal/mol) Reaction (M1) -12.93 0.70

Reaction (M2) -12.76 0.70

Reaction (M3) -13.73 0.28

Reaction (M4) -12.03 0.44

Reaction (M5) -12.43 0.03

Reaction (M6) -11.42 0.34

Reaction (M7) -5.66 4.21

Reaction (M8) -6.43 3.22

Reaction (M9) -3.63 6.89

Table 1. Summary of Gibbs free energy of reaction and enthalpy of reaction for the ring-opening reaction of each monomer

Figure 2. Optimized structures of all ring-closed monomers (RCM) and ring-opened monomers (ROM). Color scheme- orange: Fe, grey: C, white: H, blue: N, red: O.

Despite all ΔH values being highly negative, ΔG for each ring-opening reaction was positive. Cyclic carbonates, M1-M6, present a small positive ΔG, ranging between 0.03 and 0.7 kcal/mol, while δ-valerolactones, M7-M9, possessed ΔG values significantly higher at 4.21, 3.22, and 6.89 kcal/mol respectively. Because ΔH is negative for each reaction, a positive ΔG must be due to entropic effects. Also, since ΔG is close to 0 kcal/mol, it is speculated that the ring- opening process could occur experimentally in monomers M1-M6 due to establishment of an equilibrium. Equilibrium would be driven forward to produce more ring-opened monomer if the monomer is constantly being consumed in subsequent polymerization reactions. To fully complete this study, transition states for each monomer should be examined to confirm the activation barrier is low for δ-valerolactone monomers with the organocatalytic system.

The optimized structures also provided interesting structural results (Figure 2). As ring- opened monomers became more flexible with the addition of methylene or ester linkers, they had a higher tendency to fold in on themselves resulting in lower energy structures. This was evident in ring-opened monomers M4 and M5 where phenyl groups were nearly parallel to ferrocene.

Re-optimizing M4 and M5 starting from rigid straight chains resulted in higher energy minima than the structures found in Figure 2. These higher energy minima also provided similar ΔG values to M7-M9 when compared to their respective ring-closed monomers and BnOH. Chain branching seen in M7-M9 prevents this type of flexibility from benefiting the overall structure.

Due to the high flexibility in these compounds, many conformations can exist. Therefore, it is possible that some of the optimized structures converged at local minima on their potential energy surfaces close to their global minimum. If this is the case, the energy difference between the structures found and their respective global minimum are hypothesized to be negligible. An

42 extensive conformational search of each structure is suggested for future computations to confirm this hypothesis.

3.3 Conclusions

A computational study was performed to confirm experimental results for ring-opening reactions of ferrocene-functionalized cyclic monomers. Ring-opened carbonate monomers were much closer in the Gibbs free energy to ring-closed monomers plus benzyl alcohol yielding a significantly lower change in Gibbs free energy (0-0.7 kcal/mol) than ring-opened

δ-valerolactone monomers (3.22 - 6.89 kcal/mol). Although enthalpies of reaction were highly negative for all reactions, this study offers some understanding why, experimentally,

δ-valerolactone monomers do not polymerize while cyclic carbonates do polymerize. The computational results also suggest that the unfavorable reactivity is a result of thermodynamic effects and is not related to the catalytic system that was used, however, transition state calculations should be performed to confirm this conclusion.

3.4 Supplementary Material

Cartesian coordinates of B3LYP/6-311+G* optimized structures

M1 RCM

C -1.91763400 -0.92346100 -0.70211000 C -1.85063400 0.18967600 0.19434000 N 0.12189200 1.64728300 -0.12574400 C 0.99439300 1.38349300 0.87698700 C 2.23641700 1.64117400 0.33694400

N 2.05297100 2.04317300 -0.95414400 N 0.77977800 2.04553400 -1.23046400 H 0.67570600 1.04112000 1.84793100 C -2.41650000 -2.04469500 0.01876000 C -2.65880600 -1.63601200 1.36300900 C -2.30633000 -0.26071700 1.47490800 Fe -3.79755700 -0.48663700 0.05663300 C -5.56015500 -1.17349800 -0.80365400 C -5.06882800 -0.04893100 -1.52934600 C -5.00550900 1.05857600 -0.63373400 C -5.45796100 0.61859700 0.64509800 C -5.80072300 -0.76091700 0.53968200 H -6.15684000 -1.38980000 1.34318900 H -5.51305400 1.22000800 1.54145500 H -4.66287000 2.05432100 -0.87827700 H -4.77627500 -0.04253700 -2.56968200 H -2.60748400 -3.02663800 -0.38996100 H -5.70250400 -2.16988700 -1.19710100 H -1.65127100 -0.90470900 -1.74973500 H -3.06574500 -2.25321900 2.15118600 C 3.59930100 1.52277400 0.94653400 C 4.37383700 0.25994600 0.51801300 C 5.67164000 0.12887200 1.29644100 O 6.45685000 -0.99375500 0.84937300 C 6.41306300 -1.46233100 -0.42212900 O 5.53861700 -0.90401100 -1.28440900 C 4.75674600 0.26615000 -0.95213100 H 3.89797400 0.23576900 -1.61806200 H 3.75408800 -0.62336700 0.71450200 H 5.50451300 -0.04972500 2.35982500 O 7.11381600 -2.37138500 -0.75604700 H 5.34753400 1.15493800 -1.19961200 H 6.28268500 1.03267400 1.19114800 H 4.18219500 2.41296600 0.68530500 H 3.50464200 1.52321000 2.03727800 H -2.39874000 0.34910900 2.36375700 C -1.34597500 1.56156900 -0.13792800 H -1.74107500 2.30234500 0.56195400 H -1.63180200 1.86567700 -1.14452900 Sum of electronic and thermal Free Energies= -2350.942233 Sum of electronic and thermal Enthalpies= -2350.862720

M1 ROM

Fe 5.55477200 -1.14814800 0.18306800 C 4.12686800 -1.55054200 1.64304300 C 4.05777400 -0.18546000 1.24594500 C 3.78231400 -0.14207400 -0.15732400 C 3.67463100 -1.49374900 -0.61680000 C 3.89244400 -2.35962400 0.49268300

C 7.19387700 -2.37690800 -0.17416400 C 7.42304400 -1.57888000 0.98483300 C 7.36276000 -0.20856500 0.59599300 C 7.09604900 -0.16002300 -0.80361100 C 6.99135700 -1.50016700 -1.27975700 H 6.77716600 -1.79840100 -2.29618900 H 7.15606900 -3.45650300 -0.20460100 H 7.58919900 -1.94744700 1.98705500 H 7.47745400 0.64311000 1.25124900 H 6.98258400 0.73587000 -1.39764100 H 3.49353400 -1.80115100 -1.63804600 H 4.34967700 -1.91076300 2.63719800 H 4.20604200 0.67367900 1.88521400 H 3.90535600 -3.43972700 0.46203000 N 2.24685000 1.67222100 -0.83910500 N 2.10711500 2.95266200 -0.45883000 C 0.12149900 2.10029400 -0.79289900 N 0.82969400 3.21210300 -0.43146100 H 0.92307700 0.07504300 -1.36115500 C -1.37425400 2.11062200 -0.85664500 C -2.08754300 2.09239000 0.51753300 C -1.55140700 3.16751700 1.48707100 C -3.59408200 2.27815000 0.33954300 O -1.46062800 4.45967100 0.90764300 H -4.10915200 2.20477000 1.29736200 H -3.81558700 3.24206700 -0.11783100 O -4.17069300 1.30737900 -0.57272600 H -1.68565400 3.00980600 -1.39760600 H -1.72124100 1.26262600 -1.45048900 H -2.22371600 3.25350900 2.34583200 H -0.57657500 2.85291600 1.87435700 H -1.91862500 1.11973600 0.99654600 C -4.53312500 0.13314000 -0.04848200 C 1.03444200 1.10250800 -1.05636700 H -0.61953100 4.49754100 0.42223600 O -5.00695300 -0.63016400 -1.04393800 O -4.44319000 -0.19090600 1.11220300 C -5.52206200 -1.93866800 -0.66747800 C -6.97629100 -1.88786500 -0.27780200 C -7.35670800 -1.85747700 1.06759100 C -8.70473200 -1.80848500 1.41901000 C -9.68559600 -1.78573400 0.42908300 C -9.31528800 -1.81370000 -0.91540600 C -7.96835000 -1.86659000 -1.26450900 H -6.59302400 -1.86074800 1.83783600 H -8.98848100 -1.78635900 2.46637000 H -10.73510300 -1.74787500 0.70337400 H -10.07517700 -1.79813800 -1.69016200 H -7.68294200 -1.88965200 -2.31242500 H -5.37537100 -2.53631900 -1.56685700 H -4.90607500 -2.33867700 0.13703000 C 3.59092600 1.09467600 -0.98248200

H 3.76689600 0.88578100 -2.04093400 H 4.26991600 1.89169900 -0.68080600 Sum of electronic and thermal Free Energies= -2697.696986 Sum of electronic and thermal Enthalpies= -2697.598237

M2 RCM

C -1.67643600 -1.05649200 -0.30321200 C -1.81294100 0.23982200 0.29040900 N 0.16845900 1.56919400 -0.25208500 C 0.99916500 1.25927500 0.77289200 C 2.26081300 1.55659300 0.30235000 N 2.12980100 2.03020300 -0.97018800 N 0.86831900 2.03842900 -1.30060700 H 0.64258500 0.85540800 1.70607600 C -2.19969900 -2.02173000 0.60204900 C -2.66500600 -1.33335600 1.76009900 C -2.42326800 0.05857000 1.57390000 Fe -3.67069800 -0.64936800 0.07508800 C -5.23354800 -1.71356700 -0.78685300 C -4.71820600 -0.76530400 -1.71813900 C -4.86533300 0.53347500 -1.14974100 C -5.47255900 0.38858700 0.13261300 C -5.70015500 -1.00080700 0.35625100 H -6.12911500 -1.43904700 1.24613400 H -5.70424500 1.18864700 0.82125200 H -4.56153800 1.46360500 -1.60913300 H -4.27517300 -0.99247700 -2.67727400 H -2.26399400 -3.08612900 0.42674200 H -5.24528900 -2.78657900 -0.91466100 H -1.25957100 -1.25978400 -1.27993800 H -3.14401900 -1.78357700 2.61792200 C 3.59717700 1.39978100 0.96027200 C 4.38469600 0.15882100 0.49279900 C 5.63713200 -0.03890500 1.32865100 O 6.44215500 -1.13276700 0.84509600 C 6.45217200 -1.52522500 -0.45244200 O 5.62421200 -0.90588900 -1.31905100 C 4.84549000 0.25554200 -0.95134600 H 4.02283600 0.28683000 -1.66136600 H 3.74754600 -0.72785500 0.59726000 H 5.41077200 -0.29230100 2.36559100 O 7.15902800 -2.42149700 -0.80767900 H 5.46339400 1.14687400 -1.10686700 H 6.25790200 0.86443200 1.32307100 H 4.19291800 2.30032500 0.77446000 H 3.45698500 1.33894000 2.04446600 H -2.69105800 0.84070500 2.26947200 C -1.31074200 1.52362100 -0.31978800 H -1.51332100 1.51548400 -1.39254300

C -1.89863400 2.79869700 0.29080100 H -1.50230100 3.67654600 -0.22216800 H -1.65160300 2.88656800 1.35145200 H -2.98549800 2.79901500 0.19162000 Sum of electronic and thermal Free Energies= -2390.237443 Sum of electronic and thermal Enthalpies= -2390.156139

M2 ROM

Fe -5.35257300 -1.26579600 -0.25860400 C -3.69223900 -1.88925400 -1.34396400 C -3.66704100 -0.47763600 -1.16698900 C -3.64640900 -0.19938000 0.23726400 C -3.65554100 -1.45748400 0.92138200 C -3.68931900 -2.49541700 -0.05408700 C -7.05096500 -2.44357500 -0.02873500 C -7.03964500 -1.84644500 -1.32325200 C -7.03217000 -0.43059000 -1.15632100 C -7.03821800 -0.15310000 0.24161100 C -7.04952700 -1.39711000 0.93900600 H -7.04186200 -1.52560400 2.01210300 H -7.03837500 -3.50344700 0.18192000 H -7.01578400 -2.37429700 -2.26602000 H -7.00473200 0.30247600 -1.94978000 H -7.02675700 0.82933800 0.69254200 H -3.66904300 -1.60192700 1.99212100 H -3.73944900 -2.40887100 -2.29036100 H -3.67614300 0.26347000 -1.95413200 H -3.73349400 -3.55553500 0.15102800 N -2.18398700 1.72171300 0.64994700 N -2.02728400 2.99323300 0.24944200 C -0.05403800 2.12993400 0.62377800 N -0.74642300 3.24076000 0.23179500 H -0.88152100 0.12295400 1.21949800 C 1.44109900 2.12682900 0.70553100 C 2.17373700 2.07520200 -0.65758000 C 1.65499000 3.12948100 -1.65866900 C 3.67799400 2.26196300 -0.46252800 O 1.56418300 4.43541700 -1.11116500 H 4.20695200 2.16191000 -1.41029800 H 3.89480900 3.23738500 -0.02788800 O 4.23878000 1.31497400 0.48406400 H 1.75418900 3.03315400 1.23353500 H 1.77179900 1.28745900 1.32059600 H 2.33771100 3.19182800 -2.51134500 H 0.68305400 2.81064300 -2.04995100 H 2.00890300 1.09226500 -1.11670900 C 4.61074900 0.12801600 -0.00305100 C -0.97979900 1.14596900 0.89623100 H 0.71807100 4.48848800 -0.63553300

O 5.06837400 -0.60840400 1.01997500 O 4.54083200 -0.22645900 -1.15626700 C 5.59118900 -1.92552400 0.68716700 C 7.05261800 -1.88283300 0.32422500 C 7.45791400 -1.87042300 -1.01421500 C 8.81220400 -1.82648100 -1.34128000 C 9.77470600 -1.79137600 -0.33382100 C 9.37962200 -1.80213500 1.00379900 C 8.02636400 -1.84957100 1.32866600 H 6.70854600 -1.88371600 -1.79824900 H 9.11521100 -1.81816400 -2.38343700 H 10.82913400 -1.75747600 -0.58910400 H 10.12509000 -1.77716700 1.79221200 H 7.72177000 -1.85900100 2.37139700 H 5.42782800 -2.50028400 1.59849800 H 4.99084700 -2.34657300 -0.11843200 C -3.54904600 1.17976800 0.83929000 H -4.17198900 1.86736600 0.26411700 C -3.94167100 1.26747100 2.31677900 H -3.86123800 2.29900000 2.66389500 H -3.29405900 0.64931700 2.94293800 H -4.97141700 0.93375100 2.45597100 Sum of electronic and thermal Free Energies= -2736.992208 Sum of electronic and thermal Enthalpies= -2736.891392

M3 RCM

C -2.51689700 1.68082300 0.79600500 C -1.64279200 0.99510300 -0.09653600 N -0.41231200 0.40329900 0.27304100 C 0.44334900 -0.34054400 -0.47751100 C 1.47070600 -0.66548400 0.37966800 N 1.19199500 -0.10799500 1.59461100 N 0.06229200 0.53381200 1.53282600 H 0.25560500 -0.57749300 -1.51119600 C -3.59042200 2.19969600 0.01784400 C -3.38197600 1.82941300 -1.34178800 C -2.17307900 1.07784000 -1.41966100 Fe -3.52195200 0.12986500 -0.16007100 C -5.33304500 -0.64368000 0.50460900 C -4.26287300 -1.15063500 1.29877800 C -3.37056500 -1.85393100 0.43828000 C -3.88939000 -1.78169600 -0.88814500 C -5.10232400 -1.03299300 -0.84730300 H -5.72371000 -0.78330200 -1.69549000 H -3.43465700 -2.20377600 -1.77331600 H -2.44923700 -2.33367900 0.73746400 H -4.13492100 -1.00452200 2.36174800 H -4.43152000 2.75763600 0.40281400 H -6.16013000 -0.04621600 0.86076500

H -2.37343600 1.77590900 1.86055000 H -4.03219800 2.05886400 -2.17338500 C 2.72310600 -1.44953500 0.13807200 C 3.94436600 -0.58755500 -0.24029500 C 5.13577900 -1.46104700 -0.59272000 O 6.31889700 -0.68093400 -0.85398900 C 6.54401500 0.52994700 -0.28727800 O 5.58224400 1.06297800 0.49593200 C 4.40185100 0.32572600 0.88429700 H 3.66673300 1.08308700 1.14700800 H 3.69061200 0.03121400 -1.10974500 H 4.97362800 -2.04088800 -1.50274000 O 7.55876100 1.12157800 -0.50664500 H 4.63568900 -0.24941500 1.78684800 H 5.36339300 -2.15745400 0.22238700 H 2.94923600 -2.02612600 1.04125100 H 2.54717900 -2.17777000 -0.66047200 H -1.74339500 0.65597300 -2.31627700 Sum of electronic and thermal Free Energies= -2311.642805 Sum of electronic and thermal Enthalpies= -2311.566753

M3 ROM

Fe -5.59292200 -0.75679500 -0.01130000 C -5.94555700 -0.65520500 -2.05647800 C -5.02212000 0.35854000 -1.67187400 C -3.89497800 -0.29594300 -1.09508900 C -4.11777700 -1.70648300 -1.11225200 C -5.39031000 -1.92324900 -1.71791600 C -6.90388100 -1.69156800 1.30402900 C -7.37788100 -0.38505400 0.98584700 C -6.38453000 0.55496000 1.38974300 C -5.29741500 -0.16986200 1.95842800 C -5.61798000 -1.55812500 1.90619800 H -4.98731000 -2.36920600 2.24197400 H -7.41808000 -2.62063900 1.10243900 H -8.31416500 -0.15050200 0.49970700 H -6.42979300 1.62650100 1.25884000 H -4.37873000 0.25952500 2.33219800 H -3.45447300 -2.46775200 -0.72863900 H -6.91237900 -0.48521200 -2.50758000 H -5.13830600 1.42592400 -1.77663900 H -5.85871600 -2.88518600 -1.86726900 N -2.72288300 0.35024900 -0.63516500 N -2.73517100 1.65994200 -0.31179300 C -0.71258100 0.87975800 -0.00608200 N -1.52937100 1.97445500 0.06485600 H -1.24241100 -1.19903500 -0.67730200 C 0.73107200 0.95097000 0.38328200 C 1.65145300 1.67447200 -0.63040100

C 1.09960400 3.04560900 -1.07421500 C 3.04847500 1.84846900 -0.04801000 O 0.70405800 3.87626000 0.00548900 H 3.72436800 2.31250600 -0.76943200 H 3.03221800 2.46640200 0.85168300 O 3.56451100 0.53494800 0.28634400 H 0.79743500 1.47370900 1.34290100 H 1.11657400 -0.05587700 0.55202900 H 1.87284000 3.59087500 -1.62362800 H 0.26353900 2.89225500 -1.76477000 H 1.73542200 1.05537700 -1.53384000 C 4.78108600 0.50830300 0.83941900 C -1.47679200 -0.17046800 -0.46106500 H -0.19886700 3.61739100 0.25328300 O 5.08606100 -0.77117500 1.10026200 O 5.47495600 1.46850100 1.07096900 C 6.40641000 -1.01868200 1.66304100 C 7.45394400 -1.20247600 0.59608900 C 8.27093400 -0.13698600 0.20376100 C 9.23409700 -0.31422700 -0.78807100 C 9.38882700 -1.55732300 -1.39950600 C 8.57815300 -2.62514700 -1.01506600 C 7.61833300 -2.44702300 -0.02181300 H 8.14111800 0.83352800 0.67029600 H 9.86365300 0.51914700 -1.08318200 H 10.14009000 -1.69506500 -2.17074500 H 8.69717300 -3.59618300 -1.48515400 H 6.99034500 -3.28139200 0.27769200 H 6.65790200 -0.19933300 2.33523000 H 6.26831300 -1.93143000 2.24191100 Sum of electronic and thermal Free Energies= -2658.398232 Sum of electronic and thermal Enthalpies= -2658.303547

M4 RCM

C -3.59749400 -1.06745700 1.04860700 C -2.81360000 -0.22205600 0.20113600 N -0.66475600 -1.21978700 -0.50205000 C 0.30361000 -0.64549600 0.24447300 C 1.27479300 -1.61755700 0.35808100 N 0.84803500 -2.72308200 -0.31700600 N -0.32051500 -2.48460500 -0.83302400 H 0.22842600 0.35942600 0.62652400 C -4.21729900 -0.25232300 2.03704300 C -3.81986200 1.09811200 1.81162000 C -2.95051000 1.11896100 0.68411400 Fe -4.79554500 0.35392200 0.13164300 C -6.86611700 0.22140100 0.02336200 C -6.27094400 -0.62843800 -0.95453500 C -5.48424200 0.18393800 -1.82259200

C -5.59374500 1.53576300 -1.38184800 C -6.44802700 1.55860400 -0.24097600 H -6.71121700 2.43254900 0.33775500 H -5.10096000 2.39023000 -1.82360500 H -4.89785000 -0.16548700 -2.66100400 H -6.37978000 -1.70200800 -1.01400900 H -4.89524600 -0.59394500 2.80616800 H -7.50272000 -0.09559300 0.83710500 H -3.71024300 -2.13717800 0.93997000 H -4.14199200 1.95887000 2.38012300 C 2.58702000 -1.57826300 1.04841100 C 5.78154200 -0.31192700 -0.45811900 C 6.82063200 0.59799500 0.18673900 O 6.27182800 1.87518500 0.57740800 C 5.21423700 2.45252300 -0.03249400 O 4.57248100 1.75589000 -1.00009600 C 5.10093600 0.52682800 -1.53312100 H 5.82111200 0.77457100 -2.32002000 H 7.63933500 0.78722000 -0.51378800 O 4.82840200 3.53395700 0.29890000 H 4.24953400 0.02109300 -1.98165000 H 7.22265700 0.16938100 1.10232300 H 2.57165100 -0.94857600 1.93811400 H -2.49920300 1.99876100 0.24523800 H 2.90240900 -2.58146900 1.33518900 C -1.95677500 -0.67204300 -0.94341700 H -1.76339900 0.15199300 -1.63467700 H -2.42238400 -1.48096000 -1.50574600 C 6.46817300 -1.53861700 -1.09065200 H 7.19268400 -1.22780500 -1.84803200 H 5.73560000 -2.19185100 -1.56978600 H 6.99585000 -2.12075700 -0.33240100 O 3.57770500 -1.03097300 0.12276900 C 4.80651500 -0.83203000 0.61569000 O 5.13427200 -1.08101400 1.74963500 Sum of electronic and thermal Free Energies= -2578.841993 Sum of electronic and thermal Enthalpies= -2578.753522

M4 ROM

Fe 4.24021000 -1.01749200 -0.52065300 C 3.96802600 -3.08110300 -0.53661300 C 3.29459300 -2.50221300 0.57561200 C 2.33949800 -1.55972600 0.07965700 C 2.42576000 -1.57208400 -1.34934900 C 3.43183700 -2.50679000 -1.72643900 C 5.79918600 -0.12269700 -1.56226900 C 6.27221600 -0.63548700 -0.31876800 C 5.54879000 0.00889700 0.72763400 C 4.62749100 0.91937100 0.13083000

C 4.78283600 0.83775500 -1.28435400 H 4.21305200 1.39015800 -2.01792900 H 6.13359700 -0.42844700 -2.54343600 H 7.02845100 -1.39713900 -0.19213300 H 5.66365600 -0.17699900 1.78615800 H 3.92358400 1.55079500 0.65450700 H 1.84772300 -0.95467900 -2.02362000 H 4.76734900 -3.80673800 -0.48651900 H 3.48197500 -2.71741800 1.61840200 H 3.75224900 -2.72103700 -2.73610700 N 0.16247100 -1.49027800 1.25241600 N -0.14001900 -1.73232200 2.54795700 C -1.71491100 -2.55365800 1.29674100 N -1.27243900 -2.37091200 2.57449400 H -0.76087400 -1.90888000 -0.63326100 C -3.01215900 -3.22267700 1.00907400 C -5.27303500 -0.67433200 -0.58489500 C -5.80098500 -0.22787300 0.78961200 C -4.70936600 0.51858000 -1.36338700 O -6.80381700 0.76695900 0.56268400 H -4.36322000 0.21049900 -2.34911900 H -5.46037200 1.30024600 -1.46332200 O -3.58093400 1.03351100 -0.61392600 H -2.95326800 -3.88396800 0.14585800 H -3.34360900 -3.77617700 1.88474300 H -6.22371100 -1.08671000 1.31914100 H -4.98377000 0.17873600 1.39174600 C -2.94186100 2.07152900 -1.15633100 C -0.79241000 -1.99063600 0.43977800 H -7.11576500 1.09883300 1.41133100 O -1.89047700 2.36085200 -0.37201500 O -3.24470700 2.64950800 -2.17026000 C -1.11403700 3.50847400 -0.77348500 C 0.06008200 3.65880800 0.15985700 C -0.00969800 3.26571800 1.49986200 C 1.07536700 3.47022400 2.35085400 C 2.23850700 4.07592300 1.87666100 C 2.31503500 4.46854200 0.54118000 C 1.23392100 4.25418700 -0.31204500 H -0.90916900 2.79005100 1.87296200 H 1.00903900 3.15697000 3.38789000 H 3.07990400 4.23955100 2.54236200 H 3.21797300 4.93523900 0.16073400 H 1.30444500 4.55674700 -1.35340700 H -0.78788700 3.38039000 -1.80744400 H -1.76236800 4.38975700 -0.74284100 O -4.08279500 -2.25462200 0.77296100 C -4.15447200 -1.71798000 -0.45557300 O -3.43407900 -2.03727400 -1.37249600 C 1.38654200 -0.75185500 0.90880700 H 1.82351600 -0.47625000 1.86798200 H 1.09594300 0.16800300 0.39668600

C -6.40938800 -1.30209200 -1.42251800 H -7.21082300 -0.57696800 -1.56787200 H -6.83140500 -2.17009900 -0.90956300 H -6.04147200 -1.62740400 -2.39740700 Sum of electronic and thermal Free Energies= -2925.597168 Sum of electronic and thermal Enthalpies= -2925.487603

M5 RCM

C 3.63657200 -1.33039300 0.33725700 C 3.02620100 -0.10410100 -0.08232500 N 0.88372900 0.11391300 1.08373300 C 0.08140000 -0.61445000 0.27605400 C -1.00330500 -0.93606400 1.06500100 N -0.80545600 -0.39051600 2.29905200 N 0.32946400 0.24309900 2.30863300 H 0.34378800 -0.85402700 -0.74114400 C 4.29560500 -1.90911700 -0.78328400 C 4.10246600 -1.04751600 -1.90205100 C 3.31556000 0.06105400 -1.47561500 Fe 5.07385400 -0.02353900 -0.37637300 C 7.10798700 -0.25239800 -0.01941500 C 6.47047100 0.30131300 1.12916400 C 5.87033100 1.53615500 0.74636100 C 6.13749700 1.74645000 -0.63871100 C 6.90258100 0.64049900 -1.11156400 H 7.24551500 0.49276500 -2.12569200 H 5.80501300 2.58741900 -1.23073700 H 5.30482000 2.19232100 1.39309000 H 6.43058300 -0.14705800 2.11162200 H 4.87075100 -2.82395600 -0.77769700 H 7.63354300 -1.19571500 -0.06080800 H 3.61039100 -1.73507600 1.33964400 H 4.50512000 -1.19351500 -2.89423000 C -2.21589100 -1.72958600 0.74846100 C -5.45698100 -0.31643600 -0.45865500 C -5.49192000 0.85598000 0.52632500 O -6.57306400 1.76170600 0.22774500 C -7.75136000 1.35637100 -0.30111800 O -7.86382500 0.07067700 -0.70251900 C -6.85868700 -0.92459900 -0.42214900 H -6.99796000 -1.69345300 -1.17951800 H -4.58949200 1.46174400 0.48190600 O -8.65023000 2.12848100 -0.45287900 H -7.07074900 -1.36495300 0.55479600 H -5.62142300 0.50134700 1.55353800 H -2.03488100 -2.47117100 -0.03054500 H 3.02370400 0.89801300 -2.09323600 H -2.58608400 -2.24141500 1.63634100 C 2.17560300 0.78054400 0.79333700

H 2.64005100 0.86926700 1.77737200 O -3.25851300 -0.81898900 0.27620300 C -4.45600400 -1.36883400 0.01896100 O -4.70145500 -2.54526500 0.13476400 C -5.06937700 0.14240500 -1.88022900 H -5.78386500 0.87133400 -2.26573600 H -5.05564600 -0.70610700 -2.56897200 H -4.08053100 0.60334400 -1.88070800 C 1.92075600 2.18211200 0.23293300 H 1.32404100 2.76457000 0.93659600 H 1.38134600 2.14189700 -0.71637600 H 2.86724800 2.69974600 0.06732300 Sum of electronic and thermal Free Energies= -2618.136846 Sum of electronic and thermal Enthalpies= -2618.045527

M5 ROM

Fe -3.82395843 -2.44303997 -1.35408397 C -3.87568245 -0.53869789 -2.18752529 C -3.01787251 -0.55822544 -1.05219673 C -1.97431670 -1.50922210 -1.29149924 C -2.19868650 -2.07050253 -2.58935435 C -3.37138007 -1.47512109 -3.13634729 C -5.19139028 -3.94823378 -1.77755306 C -5.77719340 -2.98927093 -0.89983148 C -4.99445216 -2.94563233 0.29103236 C -3.92499672 -3.87712327 0.14858243 C -4.04565381 -4.49706358 -1.13029606 H -3.37263374 -5.23371289 -1.54544403 H -5.54004432 -4.19611692 -2.77009265 H -6.64689939 -2.38330690 -1.11053995 H -5.16804061 -2.30326265 1.14263757 H -3.15069556 -4.06816764 0.87827757 H -1.60194566 -2.83638337 -3.06297826 H -4.77007267 0.05805102 -2.29701207 H -3.13634601 0.03106122 -0.15331006 H -3.81567684 -1.71371199 -4.09220774 N 0.16909000 -0.67929329 -0.45032981 N 0.81542127 -0.27307857 0.66417574 C 1.62492096 0.79913263 -1.04291037 N 1.69373440 0.61881236 0.30734651 H 0.27411070 -0.20325807 -2.53522445 C 2.52924384 1.74681572 -1.74812667 C 4.56171731 -0.14183945 -4.28064631 C 5.51940405 -0.68282287 -3.20343687 C 4.07308580 -1.26804033 -5.19332543 O 6.59001717 -1.35184965 -3.87565957 H 3.37535772 -0.88791010 -5.93823989 H 4.91629698 -1.74527434 -5.68878156 O 3.38925094 -2.25068289 -4.37671812

H 2.00012415 2.35822976 -2.47788158 H 3.03195822 2.38099580 -1.02131849 H 5.89977565 0.14521071 -2.59958320 H 4.98651420 -1.37502105 -2.54440206 C 2.94742711 -3.32849753 -5.02801738 C 0.64363759 -0.03509059 -1.53835561 H 7.19404299 -1.71704307 -3.22029095 O 2.30898366 -4.11731471 -4.14682802 O 3.09140976 -3.56223143 -6.20257351 C 1.82166183 -5.36888490 -4.69283550 C 1.16530445 -6.15644965 -3.59159223 C -0.10977169 -6.69458102 -3.77898501 C -0.70677817 -7.47316260 -2.78677595 C -0.03581532 -7.70999201 -1.58965567 C 1.23525883 -7.16815298 -1.39084636 C 1.83346456 -6.40132487 -2.38643364 H -0.64054892 -6.50925316 -4.70853613 H -1.69479998 -7.89162383 -2.95052501 H -0.49780791 -8.31391895 -0.81526135 H 1.76268254 -7.34878094 -0.45963098 H 2.82066804 -5.98034412 -2.22643915 H 1.12341060 -5.15739328 -5.50422010 H 2.67211801 -5.90625468 -5.12101345 O 3.61903556 1.05659889 -2.43697318 C 3.34429637 0.54816400 -3.65051843 O 2.27426809 0.66379370 -4.20013133 C -0.82059364 -1.77859637 -0.36019531 H -1.17280657 -1.72167461 0.67177657 C -0.11327255 -3.11901680 -0.57839190 H 0.68454291 -3.24059854 0.15622951 H 0.33343762 -3.18330086 -1.57271542 H -0.81764710 -3.94435257 -0.46563530 C 5.28165881 0.90585647 -5.16186230 H 6.16057490 0.45861368 -5.62734923 H 5.61328597 1.75342988 -4.55764964 H 4.61952711 1.28234207 -5.94476758 Sum of electronic and thermal Free Energies= -2964.892682 Sum of electronic and thermal Enthalpies= -2964.780255

M6 RCM

C -3.23336100 1.46916600 1.10563600 C -2.57101700 0.80955400 0.02884600 N -1.50113500 -0.10892400 0.16117200 C -0.46082400 -0.31104200 -0.68394000 C 0.30994600 -1.26985700 -0.06443900 N -0.29201800 -1.59751400 1.11520900 N -1.38121400 -0.90583800 1.25427000 H -0.34650000 0.23746100 -1.60389500 C -4.17809100 2.36558000 0.52966300

C -4.09480400 2.26000900 -0.88943300 C -3.10184300 1.28872500 -1.20798500 Fe -4.59284300 0.41785300 -0.06427000 C -6.51847100 -0.05516100 0.55416000 C -5.57718800 -0.93185200 1.16949800 C -4.88385400 -1.62874000 0.13813000 C -5.39644700 -1.18391400 -1.11556500 C -6.40644000 -0.20996000 -0.85884200 H -6.97079600 0.33222700 -1.60417600 H -5.06262200 -1.51026700 -2.09037600 H -4.08403500 -2.34011800 0.28665500 H -5.39542800 -1.02951100 2.23008300 H -4.85694000 3.00096500 1.07978700 H -7.18230400 0.62614700 1.06715300 H -3.04690700 1.29717400 2.15446900 H -4.69720500 2.80034800 -1.60507500 C 1.59384100 -1.88522000 -0.48272100 C 4.97033900 -0.42115100 0.15913200 C 4.64446100 0.99236100 -0.33342100 O 5.71475400 1.91269300 -0.04952800 C 7.01899600 1.54699100 -0.03921800 O 7.31423500 0.23271900 -0.14058800 C 6.32532300 -0.76848400 -0.45710800 H 6.72999100 -1.70179300 -0.07071700 H 3.76952100 1.40901900 0.16104300 O 7.87940200 2.36271300 0.10477400 H 6.25403500 -0.85145800 -1.54410200 H 4.47200300 0.99898300 -1.41479500 H 1.73550900 -2.84668000 0.01018000 H -2.81530300 0.96391100 -2.19764400 H 1.65646100 -2.03417600 -1.56134900 O 2.68143000 -0.99411900 -0.08260800 C 3.92791200 -1.40820200 -0.36644000 O 4.18433500 -2.43474000 -0.94718600 C 5.00437600 -0.49506200 1.70035600 H 5.76272200 0.17559500 2.10742200 H 5.24338000 -1.50826900 2.03246900 H 4.03853200 -0.21439500 2.12255600 Sum of electronic and thermal Free Energies= -2539.540701 Sum of electronic and thermal Enthalpies= -2539.456675

M6 ROM

Fe -5.592922 -0.756795 -0.011300 C -5.945526 -0.655204 -2.056471 C -5.022089 0.358541 -1.671867 C -3.894947 -0.295942 -1.095082 C -4.117746 -1.706482 -1.112245 C -5.390279 -1.923248 -1.717909 C -6.903881 -1.691568 1.304029

C -7.377881 -0.385054 0.985847 C -6.384530 0.554960 1.389743 C -5.297415 -0.169862 1.958428 C -5.617980 -1.558125 1.906198 H -4.987310 -2.369206 2.241974 H -7.418080 -2.620639 1.102439 H -8.314165 -0.150502 0.499707 H -6.429793 1.626501 1.258840 H -4.378730 0.259525 2.332198 H -3.454442 -2.467751 -0.728632 H -6.912348 -0.485211 -2.507573 H -5.138275 1.425925 -1.776632 H -5.858685 -2.885185 -1.867262 N -2.722852 0.350250 -0.635158 N -2.735140 1.659943 -0.311786 C -0.712550 0.879759 -0.006075 N -1.529340 1.974456 0.064863 H -1.242380 -1.199034 -0.677295 C 0.796403 0.922366 0.350389 C 2.883088 -1.482585 2.359748 C 2.222125 -2.842413 2.050680 C 4.398967 -1.634166 2.343655 O 2.577304 -3.372828 0.783910 H 4.730262 -2.387432 3.061599 H 4.761331 -1.921602 1.354905 O 4.983636 -0.359179 2.712428 H 1.359370 0.393558 -0.425471 H 1.146594 1.955811 0.336798 H 2.532652 -3.578558 2.798160 H 1.134574 -2.742300 2.131910 C 6.319335 -0.309230 2.720819 C -1.476761 -0.170467 -0.461058 H 2.015056 -4.149542 0.628096 O 6.681927 0.936730 3.058787 O 7.063849 -1.222831 2.459888 C 8.112513 1.183912 3.175522 C 8.423064 2.645187 3.369750 C 8.643996 3.166328 4.648914 C 8.925438 4.520675 4.820264 C 8.986494 5.368278 3.715310 C 8.766908 4.857421 2.436232 C 8.488761 3.503390 2.266619 H 8.583132 2.509098 5.509582 H 9.096945 4.913666 5.817304 H 9.207204 6.422561 3.849303 H 8.817191 5.512279 1.572118 H 8.321127 3.107717 1.268828 H 8.505352 0.578427 3.991294 O 1.116687 0.350346 1.598713 C 2.373732 -0.259509 1.408937 O 3.121270 0.139299 0.521845 H 8.513418 0.815922 2.224168

C 2.462041 -1.094021 3.779501 H 2.910865 -0.129357 4.042553 H 2.803822 -1.860372 4.484559 H 1.370019 -1.014171 3.827752 Sum of electronic and thermal Free Energies= -2886.296039 Sum of electronic and thermal Enthalpies= -2886.189788

M7 RCM

C 5.28538000 -1.12847700 1.18670100 C 6.05571800 -0.02224000 0.72311900 C 6.00568100 -0.01649300 -0.70166500 C 5.20501400 -1.11965800 -1.11967200 C 4.75960600 -1.80676900 0.04755000 Fe 4.08883300 0.16209300 0.07756300 H 6.47205200 0.71109400 -1.35047200 H 4.96119600 -1.37661900 -2.14063500 H 4.12499900 -2.68195000 0.06553600 H 5.11385300 -1.39441000 2.22016300 H 6.56729900 0.70012900 1.34316200 C 2.02109200 0.17880900 0.08228300 C 2.52090900 0.81602000 1.26269000 C 3.32040400 1.92559700 0.86490000 C 3.31210900 1.98545600 -0.55943900 C 2.51260400 0.91219900 -1.04313100 H 2.31899300 0.67717600 -2.08044100 H 3.86093900 2.58831600 1.52557400 H 2.34797500 0.48905700 2.27930700 C 1.09861400 -1.00267600 0.02841400 H 1.15179700 -1.58068400 0.95465500 H 1.34500900 -1.66891100 -0.79793900 N -0.29967200 -0.61920800 -0.20358100 N -0.93685300 -1.04069500 -1.31140700 H -4.16751200 -1.83971900 0.30410400 C -2.30474400 0.20133000 -0.15395500 C -1.11949800 0.15684700 0.54841800 H -0.80152000 0.61150000 1.47236000 C -3.57451300 0.94072700 0.14649400 H -3.59288200 1.88448400 -0.40364000 H -3.59886000 1.20906500 1.20809700 C -4.83916600 0.14359400 -0.21993600 H -4.75888400 -0.11742000 -1.28401700 C -6.07380300 1.04727700 -0.15017600 O -6.02902900 2.23194400 -0.35990200 O -7.28833600 0.47777800 0.06445600 C -7.45042000 -0.84733800 0.62198700 C -6.33914700 -1.80671200 0.24140300 C -4.99037500 -1.16934700 0.56089300 H -4.91829900 -0.97572500 1.63973300 H -6.48015000 -2.74334700 0.79098100 H -6.39830200 -2.04984500 -0.82547300

H -8.42692000 -1.17851300 0.26696200 H -7.50700000 -0.73255000 1.71029100 N -2.14383600 -0.54791100 -1.28291300 H 3.84521500 2.70249300 -1.16734300 Sum of electronic and thermal Free Energies= -2314.995790 Sum of electronic and thermal Enthalpies= -2314.917526

M7 ROM

C 6.92443700 -0.22248500 1.36609800 C 6.57413600 1.00267900 0.72656600 C 6.96888600 0.91550300 -0.64102700 C 7.56314600 -0.36370800 -0.84660800 C 7.53516500 -1.06708100 0.39323400 Fe 5.60101400 -0.58631300 -0.19516800 C 3.91697300 -1.52033000 0.57507100 C 3.55873400 -0.29104500 -0.06228900 C 3.95308000 -0.38747100 -1.43503900 C 4.55762700 -1.66130900 -1.63641500 C 4.53298000 -2.36093500 -0.39429500 C 2.85602300 0.86609900 0.58334700 N 1.40650600 0.66484000 0.69811200 C 0.48121000 0.45208400 -0.27025000 C -0.71421400 0.33357600 0.40517400 N -0.45447600 0.47984900 1.73721600 N 0.82069400 0.67960100 1.91165700 C -2.09507000 0.07767000 -0.11376500 C -3.10041400 1.21184600 0.22841600 C -2.74844300 2.53777600 -0.46047700 C -3.62036700 3.71238900 -0.00413700 C -3.24699900 5.01453700 -0.69241900 O -4.10298600 6.04251000 -0.18926000 C -4.48393100 0.73446000 -0.18653200 O -5.16433100 0.22447300 0.86200500 C -6.47743700 -0.34846900 0.59419800 C -6.39131000 -1.80745500 0.22802300 C -6.42140100 -2.21339000 -1.11017900 C -6.33812100 -3.56501200 -1.44046700 C -6.21956200 -4.52503200 -0.43674700 C -6.18684600 -4.12954900 0.90028300 C -6.27397000 -2.77878500 1.22851900 O -4.91814200 0.77223900 -1.31465300 H 7.89292800 -2.07299000 0.56079000 H 6.73967100 -0.47510100 2.40047700 H 6.08419200 1.84549100 1.19406300 H 6.82484200 1.67726000 -1.39411300 H 7.94533900 -0.74334500 -1.78357400 H 3.76000300 -1.75646500 1.61833000 H 4.98465200 -2.02270200 -2.56107800 H 3.84158100 0.38809300 -2.18099600

H 3.03620200 1.78877000 0.02531800 H 3.19598200 1.02236500 1.60687900 H -1.69673500 2.76086400 -0.25161900 H 0.73708700 0.38817800 -1.31517400 H -2.46340200 -0.86043000 0.31400100 H -2.06225800 -0.06146300 -1.19835600 H -3.09517500 1.34086200 1.31331500 H -2.83633600 2.40401600 -1.54442200 H 4.93806500 -3.34622800 -0.21270300 H -3.52819300 3.85321400 1.07839500 H -4.67681700 3.50943900 -0.20844500 H -3.89456000 6.87583200 -0.62676300 H -3.36634400 4.91450000 -1.78054900 H -2.19433000 5.26162100 -0.49183100 H -6.95732600 0.23429000 -0.19101500 H -7.01574100 -0.20703900 1.53098000 H -6.50022800 -1.46515200 -1.89151200 H -6.36557600 -3.86818500 -2.48234900 H -6.25119300 -2.47450900 2.27111700 H -6.09808700 -4.87270000 1.68633600 H -6.15587500 -5.57753800 -0.69445600 Sum of electronic and thermal Free Energies= -2661.744950 Sum of electronic and thermal Enthalpies= -2661.642396

M8 RCM

N -2.18427400 -0.53410500 -1.36446700 N -0.98299100 -1.04099800 -1.41805800 N -0.31303700 -0.61558200 -0.33205100 C -1.10659700 0.17223300 0.43598300 C -2.30826700 0.22527200 -0.23824800 C 1.07915200 -1.06123800 -0.11083400 C 1.94840000 0.11774800 0.25267200 C 2.52775800 0.42378700 1.52594800 C 3.21553700 1.66696300 1.41589500 C 3.05876400 2.14153600 0.08134300 C 2.28178000 1.18951800 -0.63592300 Fe 4.00639000 0.29013900 0.07501500 C 4.78261800 -1.49073200 -0.66707900 C 5.36235300 -1.19777500 0.60265900 C 6.02798300 0.05876500 0.50254300 C 5.85933500 0.54208300 -0.82810600 C 5.09001300 -0.41593400 -1.55156700 C -3.55763700 0.99143800 0.08180100 C -4.84408200 0.22600700 -0.27548600 C -6.05656700 1.15797100 -0.19312300 O -7.28242200 0.61576000 0.02861200 C -7.47028800 -0.70583800 0.58629100 C -6.38517500 -1.69034800 0.19457300 C -5.01906200 -1.08518800 0.50321300

O -5.98635500 2.34194800 -0.39990500 H 6.22804300 1.48186900 -1.21378500 H 4.77578500 -0.33147900 -2.58208200 H 4.20210800 -2.36849300 -0.91462400 H 5.29635800 -1.81188500 1.48968000 H 6.54778700 0.56761800 1.30188300 H 1.99660000 1.25318700 -1.67686300 H 3.77901700 2.15059300 2.20115300 H 2.48632500 -0.19438000 2.41108600 C 1.11305700 -2.21238300 0.89789100 H 1.37662500 -1.43892700 -1.09094500 H -4.21445400 -1.77374700 0.23702800 H -0.75931700 0.63454000 1.34530900 H -3.56110400 1.93917800 -0.46180200 H -3.56409100 1.25327100 1.14532200 H -4.77930400 -0.03403000 -1.34090400 H -4.93254500 -0.89627300 1.58182400 H -6.54341100 -2.62442600 0.74385900 H -6.45937400 -1.92996600 -0.87217400 H -8.45744400 -1.01365600 0.23976900 H -7.51441700 -0.59122600 1.67521300 H 3.48255000 3.04920300 -0.32415400 H 0.48871900 -3.03616900 0.54756800 H 2.13453500 -2.57836000 1.01958300 H 0.74273400 -1.90022500 1.87735600 Sum of electronic and thermal Free Energies= -2354.290703 Sum of electronic and thermal Enthalpies= -2354.210508

M8 ROM

C -6.24371900 -2.89977800 1.24229500 C -6.38832600 -1.92614500 0.24765400 C -6.40746800 -2.32489300 -1.09296100 C -6.28760500 -3.67178100 -1.43119700 C -6.14277300 -4.63417900 -0.43318400 C -6.12004900 -4.24576600 0.90612400 C -6.51650800 -0.47248300 0.62270400 O -5.22041200 0.13910100 0.88714600 C -4.56066200 0.67358900 -0.16277600 O -5.00230700 0.70272700 -1.28824900 C -3.18924700 1.18829400 0.24772700 C -2.85974500 2.50566700 -0.46747200 C -3.75152300 3.67366700 -0.03300800 C -3.40326900 4.96798000 -0.74855800 O -4.27451000 5.99135000 -0.26215400 C -2.16020200 0.06672700 -0.06292600 C -0.78533900 0.36472700 0.45079500 C 0.41661700 0.43223900 -0.22063300 N 1.33456700 0.70565000 0.73963100 N 0.73783200 0.80987900 1.94254200

N -0.53765300 0.60237000 1.77134700 C 2.78997800 0.93495900 0.62252800 C 3.43374600 -0.19089000 -0.14867100 C 3.61067700 -1.52255200 0.34600500 C 4.18462900 -2.31300800 -0.68872200 C 4.36947800 -1.47886700 -1.82941900 C 3.90338100 -0.17275600 -1.50131000 Fe 5.43721700 -0.72261300 -0.21590300 C 7.26215000 -1.52163900 0.37577400 C 6.70345700 -0.74663700 1.43402300 C 6.54158800 0.58876500 0.96266900 C 6.99997600 0.63942300 -0.38686000 C 7.44589900 -0.66516700 -0.74904700 H 7.48469600 -2.57855000 0.41224400 H 6.43038100 -1.11219000 2.41363200 H 6.13270600 1.41459600 1.52782500 H 6.99426300 1.50930300 -1.02842800 H 7.83158000 -0.95915800 -1.71482800 H 3.35995800 -1.85994000 1.34217900 H 4.81187100 -1.77548700 -2.76977800 H 3.93433100 0.68710100 -2.15499800 C 3.05825500 2.33266200 0.05794100 H 3.12993700 0.89812200 1.65928600 H -1.81207500 2.75052600 -0.26310500 H 0.68172600 0.29004300 -1.25535700 H -2.51162200 -0.86710800 0.38809500 H -2.12116700 -0.10063100 -1.14344200 H -3.19197600 1.34086000 1.32961000 H -2.94552200 2.34967600 -1.54854600 H 4.46247800 -3.35450100 -0.61124400 H -3.65889000 3.83808900 1.04618200 H -4.80458900 3.44753800 -0.23012700 H -4.08304400 6.81870600 -0.71833500 H -3.52535400 4.84435000 -1.83394900 H -2.35415300 5.23679100 -0.55755100 H -7.01818100 0.09974200 -0.15664800 H -7.05409600 -0.35301200 1.56294800 H -6.50662100 -1.57435000 -1.86974300 H -6.30728600 -3.96942800 -2.47485600 H -6.22910400 -2.60113900 2.28667000 H -6.01085000 -4.99084300 1.68778200 H -6.05092500 -5.68305600 -0.69712900 H 2.58459200 3.08786200 0.68772300 H 4.13142600 2.52911400 0.02644800 H 2.66208100 2.44125900 -0.95462700 Sum of electronic and thermal Free Energies= -2701.041449 Sum of electronic and thermal Enthalpies= -2700.935673

M9 RCM

C -1.64166500 0.35790100 0.93049500 C -2.39875600 -0.52922800 1.74989300 C -3.56548600 0.17419200 2.16613600 C -3.52578100 1.48448900 1.60591900 C -2.33562300 1.60220600 0.82957300 Fe -3.50868600 0.06143400 0.09362100 C -3.99806200 -1.64982600 -0.97397400 C -5.18545700 -0.97897300 -0.55769700 C -5.17310100 0.33022600 -1.12281700 C -3.97820900 0.46658600 -1.88963800 C -3.25190800 -0.75682500 -1.79627500 H -5.94786600 -1.38208200 0.09370800 H -5.92488000 1.09297100 -0.97703300 H -3.66717300 1.35100300 -2.42748200 H -2.28688600 -0.96270200 -2.23677400 H -3.69631500 -2.64760100 -0.68981900 H -2.12625500 -1.54625400 1.98541800 H -4.35523900 -0.22888300 2.78344900 H -4.27797500 2.25120000 1.72222500 H -2.02545300 2.46466500 0.25807700 N -0.37955200 0.06930800 0.36043300 C 0.61869300 0.93148400 0.03060400 C 1.62710100 0.13479200 -0.46537700 N 1.19459400 -1.16079100 -0.40823900 N -0.00827500 -1.20310700 0.08639000 C 2.97621700 0.52585300 -0.98305600 H 0.54075000 1.99524700 0.18119200 C 4.13618900 0.20335900 -0.01483800 H 3.15753000 0.01750000 -1.93616800 H 2.98867500 1.59572200 -1.19305500 C 5.38126800 1.02242900 -0.38760000 H 3.86248700 0.59704200 0.97558300 O 6.60435400 0.54137500 -0.05506600 C 6.84449600 -0.84476000 0.29010300 C 5.66831900 -1.51001200 0.97783300 H 7.09527700 -1.36678300 -0.63960600 H 7.73733100 -0.82055500 0.91571200 C 4.41108000 -1.29858500 0.14040700 H 5.89048800 -2.57499400 1.10139300 H 5.53380800 -1.09359500 1.98311300 H 4.54457900 -1.75207200 -0.85006300 H 3.54147000 -1.78898700 0.58053000 O 5.31292300 2.11764300 -0.88403000 Sum of electronic and thermal Free Energies= -2275.696252 Sum of electronic and thermal Enthalpies= -2275.622900

M9 ROM

C 3.09676800 -0.17932600 0.89963000 C 4.11024200 0.64787800 1.46586400 C 4.97855800 -0.20036700 2.21108000 C 4.50044900 -1.53954900 2.10614800 C 3.33484400 -1.53387200 1.28551200 Fe 4.94876100 -0.79141700 0.22035500 C 5.96651100 0.20620000 -1.28777100 C 6.87013800 -0.61249900 -0.54824100 C 6.42630200 -1.96368100 -0.65236900 C 5.24923600 -1.97866100 -1.45818800 C 4.96520800 -0.63747300 -1.84972900 N 1.99677200 0.27474000 0.13442200 C 0.73291600 -0.22609200 0.10040700 C 0.05079800 0.59502800 -0.77104000 N 0.92713000 1.54389300 -1.21462300 N 2.09586100 1.35448000 -0.67528400 C -1.37457500 0.55681100 -1.22909900 C -2.40584900 0.86736200 -0.10804100 C -3.83032700 0.67434000 -0.62140300 O -3.99899500 -0.57135000 -1.12621600 C -2.22221100 2.23340300 0.57501600 C -2.17053100 3.44755900 -0.36145400 C -2.24209600 4.76599600 0.39191300 O -1.12790600 4.84717900 1.28696400 H -1.17418800 5.67441500 1.77916500 C -5.32425700 -0.92791100 -1.61607500 C -6.16083700 -1.57615900 -0.54369500 C -7.02947000 -0.81551500 0.24677200 C -6.07111600 -2.95393300 -0.31822700 C -7.79139900 -1.42263400 1.24328300 C -6.83067700 -3.56235600 0.67840400 C -7.69303600 -2.79617000 1.46177900 O -4.71452100 1.49601200 -0.57644600 H 4.19236200 1.71515400 1.32911800 H 5.86111100 0.11807700 2.74688500 H 4.95546900 -2.41509800 2.54623800 H 2.74902700 -2.39359700 0.99430700 H 6.00804000 1.28195700 -1.37885200 H 7.72538200 -0.26709100 0.01509800 H 6.88689400 -2.82186000 -0.18364700 H 4.66140100 -2.85125800 -1.70608800 H 4.11752200 -0.30613900 -2.43218700 H 0.43638000 -1.07667900 0.69131400 H -1.60440200 -0.42518600 -1.64781300 H -1.47893200 1.27781300 -2.04329900 H -2.28349900 0.09190600 0.66016800 H -1.30243100 2.20501000 1.16347100 H -3.03943900 2.36477800 1.29190700 H -3.01179600 3.42353300 -1.06125800

H -1.24874500 3.43348400 -0.95090600 H -3.18546800 4.82699300 0.95354300 H -2.21898100 5.60169300 -0.32056300 H -5.12440400 -1.62181000 -2.43242600 H -5.80084900 -0.03168600 -2.01071200 H -7.09891600 0.25447900 0.08269700 H -5.40385700 -3.55480400 -0.92989600 H -8.46361000 -0.82282000 1.84857500 H -6.75369600 -4.63283300 0.84046900 H -8.28867000 -3.26839700 2.23658700 Sum of electronic and thermal Free Energies= -2622.441146 Sum of electronic and thermal Enthalpies= -2622.343602

BnOH

C -0.45591400 0.00008200 -0.28853100 C 0.24475100 1.20316000 -0.16387200 C 1.61652500 1.20587400 0.08009500 C 2.30562100 -0.00009900 0.20160400 C 1.61648400 -1.20595600 0.07987600 C 0.24455700 -1.20301200 -0.16375200 H -0.28936300 2.14467000 -0.25412300 H 2.14771800 2.14786300 0.17341100 H 3.37473900 -0.00004600 0.38911200 H 2.14745300 -2.14807000 0.17307300 H -0.28949100 -2.14456800 -0.25392100 C -1.94269000 0.00003500 -0.52086100 O -2.60511100 -0.00007600 0.75175500 H -2.23333800 0.88741200 -1.09804600 H -2.23312000 -0.88729200 -1.09820100 H -3.55972600 0.00012900 0.60731000 Sum of electronic and thermal Free Energies= -346.755876 Sum of electronic and thermal Enthalpies= -346.714914

3.5 References

(1) Manners, I. Chem. Commun., 1999, 857-865.

(2) Kulbaba, K.; Manners, I. Macromol. Rapid. Commun., 2001, 22, 711.

(3) Cyr, P.; Tzolov, M.; Manners, I.; Sargent, E. H. Macromol. Chem. Phys., 2003, 204, 915-

921.

(4) Caldwell, G.; Meirim, M. C.; Neuse, E. W.; Beloussow, K.; Shen, W.-C. J. Inorg.

Organomet. Polym., 2000, 10, 93.

(5) Hillard, E.; Vessieres, A.; Thouin, L.; Jaouen, G.; Amatore, C. Angew. Chem. Int. Ed.,

2006, 45, 285-290.

(6) Upton, B. M.; Matsumoto, N. M.; Gipson, R. M.; Duhović S.; Lydon B. R.; Maynard, H.

D.; Diaconescu, P. L. Inorganic Chemistry Frontiers, manuscript submitted.

(7) Albertsson, A. C.; Sjoeling, M. J. J. Macromol. Sci. Pure Appl., Chem. 1992, 43.

(8) Kricheldorf, H. R.; Kreiser-Saunders, I.; Boettcher, C. Polymer, 1995, 1253.

(9) Zhu, K. J.; Hendren, R. W.; Jensen, K.; Pitt, C. G. Macromolecules, 1991, 24, 1736.

(10) Rokick, G. Prog. Polym. Sci., 2000, 259.

(11) Williams, R. J.; Barker, I. A.; O’Reilly, R. K.; Dove, A. P. ACS Macro Letters, 2012, 1,

1285.

(12) A. D. Becke, A, D. J. Chem. Phys., 1993, 98, 5648-5652.

(13) Gaussian 09, Revision B.01, M. J. Frisch, G. W. Trucks, H. B. Schlegel, G. E. Scuseria,

M. A. Robb, J. R. Cheeseman, G. Scalmani, V. Barone, B. Mennucci, G. A. Petersson, H.

Nakatsuji, M. Caricato, X. Li, H. P. Hratchian, A. F. Izmaylov, J. Bloino, G. Zheng, J. L.

Sonnenberg, M. Hada, M. Ehara, K. Toyota, R. Fukuda, J. Hasegawa, M. Ishida, T.

Nakajima, Y. Honda, O. Kitao, H. Nakai, T. Vreven, J. A. Montgomery, Jr., J. E. Peralta,

F. Ogliaro, M. Bearpark, J. J. Heyd, E. Brothers, K. N. Kudin, V. N. Staroverov, T.

Keith, R. Kobayashi, J. Normand, K. Raghavachari, A. Rendell, J. C. Burant, S. S.

Iyengar, J. Tomasi, M. Cossi, N. Rega, J. M. Millam, M. Klene, J. E. Knox, J. B. Cross,

V. Bakken, C. Adamo, J. Jaramillo, R. Gomperts, R. E. Stratmann, O. Yazyev, A. J.

Austin, R. Cammi, C. Pomelli, J. W. Ochterski, R. L. Martin, K. Morokuma, V. G.

Zakrzewski, G. A. Voth, P. Salvador, J. J. Dannenberg, S. Dapprich, A. D. Daniels, O.

Farkas, J. B. Foresman, J. V. Ortiz, J. Cioslowski, and D. J. Fox, Gaussian, Inc.,

Wallingford CT, 2010.