DOCSLIB.ORG

ABSTRACT PÉREZ, DAMARIS ESTHER. Synthesis, Characterization and Reactivity of Rhenium(III) Complexes for Catalytic, Stoichiomet

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
ABSTRACT PÉREZ, DAMARIS ESTHER. Synthesis, Characterization and Reactivity of Rhenium(III) Complexes for Catalytic, Stoichiomet ABSTRACT PÉREZ, DAMARIS ESTHER. Synthesis, Characterization and Reactivity of Rhenium(III) Complexes for Catalytic, Stoichiometric and Insertion Reactions. (Under the direction of Elon A. Ison). This document focuses on the synthesis and characterization of new rhenium(III) complexes bearing tridentate pincer ligands. These organometallic complexes were subject to comprehensive studies of their reactivity towards catalytic, stoichiometric and insertion reactions. Mechanistic studies of these transformations will lead to the development of more efficient catalytic systems. In Chapter 2, cationic bisacetonitrile diamidoamine (DAAm) rhenium(III) and cationic diamineamido (DAmA) rhenium(III) complexes were synthetized, and characterized. Their reactivity towards the hydrosilylation reaction of aldehydes was studied. It was proposed through experimental and kinetic data that the most likely pathway for this transformation follows a non- hydride ionic hydrosilylation mechanism. Various aliphatic and aromatic aldehydes were tested. Excellent yields were achieved at ambient temperature in neat conditions using dimethylphenylsilane. The reaction affords TONs of up to 9,200 and a TOF of up to 126 h-1. In Chapter 3, a computational mechanistic study of the hydrosilylation reaction of aldehydes by novel cationic rhenium(III) bisacetronitrile complex is presented. DFT analysis supports a non-hydride ionic hydrosilylation mechanism which was previously proposed based on experimental and kinetic data. In Chapter 4, the reactivity of novel DAAm-C6F5 rhenium(III) acetate complex towards Lewis acidic boron reagents was investigated. The role of water as an oxygen source was studied. Novel rhenium(III) and rhenium(V) complexes bearing a C6F5 ligand were synthesized, characterized, and proposed as intermediates. Mechanistic transformations were proposed base on experimental data and previous reports in the literature. In Chapter 5, new diamidoamine (DAAm) rhenium(III) aryl complexes were synthetized and characterized. Kinetic studies suggest a pseudo-first order overall reaction. The mechanism for the CO insertion with rhenium(III) complexes was proposed. Comparison of rhenium(III) versus rhenium(V) for CO activation was established. © Copyright 2018 Damaris Esther Pérez All Rights Reserved Synthesis, Characterization and Reactivity of Rhenium(III) Complexes for Catalytic, Stoichiometric and Insertion Reactions by Damaris Esther Pérez A dissertation submitted to the Graduate Faculty of North Carolina State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy Chemistry Raleigh, North Carolina 2018 APPROVED BY: ______________________________ _____________________________ Dr. Elon A. Ison Dr. Reza Ghiladi Committee Chair ______________________________ _____________________________ Dr. Elena Jakubikova Dr. Joshua Pierce DEDICATION To my husband, Hernán To my baby girl, Sofía Esther To my parents, Zory and Fidel To my sisters, Sandra and Vivian To my grandparents, Mama Candy (1928 - 2012) and Papa Tato For your support and unconditional love. ii BIOGRAPHY Damaris Esther Pérez (formerly Rivera-Santos) was born on September 13th, 1986 in Aibonito, Puerto Rico. She and her sisters, Sandra and Vivian were raised by their parents, Fidel and Zoraida. From an early age, she had a passion for math and science. Damaris graduated from Bonifacio Sánchez Jiménez high school in May 2004 and moved to San Juan, Puerto Rico to complete her undergraduate degree at University of Puerto Rico at Río Piedras (UPR-RP). She graduated with a Bachelor of Science degree in Chemistry in May 2009. Upon graduation, she stayed at UPR-RP took graduate courses and worked as a teaching assistant. Then, in August 2010, she moved to Oswego, New York to pursue a Master’s Degree in Chemistry at the State University of New York (SUNY) at Oswego. She conducted graduated research under the supervision of Dr. Fehmi Damkaci in organic chemistry and worked as a teaching assistant. She graduated with a M.S. in chemistry in May 2012 and then moved to Lincoln, Nebraska. In August 2012, she started graduated research under the supervision of Dr. James Takacs in organic chemistry and worked as a teaching assistant at University of Nebraska Lincoln (UNL). In May 2013, she moved to Raleigh, North Carolina to pursue her Ph.D. in Chemistry at North Carolina State University. Since arriving to NC State University, she has been conducting her doctoral research in organometallic chemistry under the direction of Dr. Elon A. Ison. Upon graduation in 2018, Damaris plans to pursue a professional career in chemical industry. iii TABLE OF CONTENTS LIST OF TABLES ......................................................................................................................... vi LIST OF FIGURES ...................................................................................................................... vii LIST OF SCHEMES ...................................................................................................................... ix Chapter 1: General Introduction ................................................................................................ 1 1.1 Organometallic Chemistry .................................................................................................... 2 1.2 Scope of this dissertation ...................................................................................................... 3 1.3 References ............................................................................................................................. 5 Chapter 2: Cationic Rhenium(III) Complexes: Synthesis, Characterization, and Reactivity for Catalytic Hydrosilylation Reaction of Aldehydes ...................................... 7 2.1 Abstract ................................................................................................................................. 8 2.2 Introduction ........................................................................................................................... 8 2.3 Results and Discussion ....................................................................................................... 10 2.4 Conclusions ......................................................................................................................... 34 2.5 Experimental Section .......................................................................................................... 35 2.6 References ........................................................................................................................... 42 Chapter 3: Mechanistic Investigation of the Hydrosilylation Reaction of Aldehydes by a Bisacetonitrile Cationic Rhenium(III) Complex: A Computational Study .................................................................................................................. 44 3.1 Abstract ............................................................................................................................... 45 3.2 Introduction ......................................................................................................................... 45 3.3 Results and Discussion ....................................................................................................... 49 3.4 Conclusions ......................................................................................................................... 59 3.5 Experimental Section .......................................................................................................... 60 3.6 References ........................................................................................................................... 61 Chapter 4: Reactivity of Novel DAAm Rhenium(III) Acetate Complex Towards Lewis Acidic Boron Reagents .................................................................................... 64 4.1 Abstract ............................................................................................................................... 65 4.2 Introduction ......................................................................................................................... 65 4.4 Conclusions ......................................................................................................................... 83 4.5 Experimental Section .......................................................................................................... 84 4.6 References ........................................................................................................................... 91 Chapter 5: Synthesis and Characterization of (DAAm)ReIII(CO)(R) Complexes, and Study of CO Insertion into Rhenium(III)-Carbon Bond ............................ 93 iv 5.1 Abstract ............................................................................................................................... 94 5.2 Introduction ......................................................................................................................... 94 5.3 Results and Discussion ....................................................................................................... 97 5.5 Conclusions ....................................................................................................................... 115 5.6 Experimental Section ........................................................................................................ 116 5.7 References ........................................................................................................................
Load more

Recommended publications
  • Reactions of an Osmium(IV)-Hydroxo Complex with Amino-Boranes: Formation of Boroxide Derivatives † ‡ ‡ § ‡ Antonio Antiñolo,*, Miguel A
    Article Cite This: Organometallics XXXX, XXX, XXX−XXX pubs.acs.org/Organometallics Reactions of an Osmium(IV)-Hydroxo Complex with Amino-Boranes: Formation of Boroxide Derivatives † ‡ ‡ § ‡ Antonio Antiñolo,*, Miguel A. Esteruelas,*, Cristina García-Yebra, , Jaime Martín, ‡ † Enrique Oñate, and Alberto Ramos † Departamento de Química Inorganica,́ Organicá y Bioquímica-Centro de Innovacioń en Química Avanzada (ORFEO−CINQA), Universidad de Castilla-La Mancha, Campus Universitario, E-13071 Ciudad Real, Spain ‡ Departamento de Química Inorganica,́ Instituto de Síntesis Química y Catalisiś Homogeneá (ISQCH), Centro de Innovacioneń Química Avanzada (ORFEO−CINQA), Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain *S Supporting Information ABSTRACT: The discovery of a reaction which allows preparation of boroxide complexes of platinum group metals and study of their behavior under CO atmosphere is described. κ3 The trihydride-osmium(IV)-hydroxo complex OsH3(OH){ - i i P,O,P-[xant(P Pr2 ) 2 ]} (1,xant(PPr2 ) 2 =4,5-bis- (diisopropylphosphino)xanthene) reacts with the amino-bor- i i anes Pr(H)NBCy2 and Pr(H)NBBN to give the osmium(IV)- κ3 i boroxide derivatives OsH3(OBR2){ -P,O,P-[xant(P Pr2)2]} (BR2 = BCy2 (2), BBN (3); BBN = 9-borabicyclo[3.5.1]- i − − nonane) and PrNH2 as a consequence of the addition of the O H bond of the hydroxo ligand of 1 to the B N bond of the ff − amino-boranes. At room temperature under CO atmosphere, complexes 2 and 3 eliminate H2 to a ord the osmium(II) κ2 i κ2 boroxide compounds OsH(OBR2)(CO)2{ -P,P-[xant(P Pr2)2]} (BR2 = BCy2 (4), BBN (5)) bearing a -P,P-coordinated ether-diphosphine.
    [Show full text]
  • CO2 Activation and Redox Activity of NN
    To ancillary and beyond: CO 2 activation and redox activity of NN chelate actor ligands by Trevor William Janes A thesis submitted in conformity with the requirements for the degree of Doctor of Philosophy Department of Chemistry University of Toronto © Copyright by Trevor Janes 2017 To ancillary and beyond: CO 2 activation and redox activity of NN chelate actor ligands Trevor William Janes Doctor of Philosophy Department of Chemistry University of Toronto 2017 Abstract This thesis examines the fundamental coordination chemistry and subsequent reactivity of actor and redox-active ligands. In this context, the two NN chelate ligand classes that are explored are 4,5-diazafluorene and o-phenylenediamine. In Chapter 2, actor diazafluorenyl ligands were explored. New Ru and Zn diazafluorenyl complexes undergo C–H borylation of the diazafluorenyl ligand to form the corresponding diazafluorenylboronic ester complexes, which can insert CO 2 into their C–B bonds to form boryl ester functionalities. The relevance of this new reactivity to catalytic CO 2 reduction was also explored. In Chapter 3, the initial coordination chemistry of the redox-active N,N’ -bis(2,6- 2- diisopropylphenyl)-o-phenylenediamido ligand (L ) was investigated. Li 2L(THF)3 reacts with iron(II) sources in toluene to yield LFe(η6-toluene). DFT, NMR, and X-ray data indicate that L2- 1- 6 oxidized to L in this transformation. [FeL(η -toluene)] reacts with CO to generate [FeL(CO) 3], - 0 with concomitant oxidation of L to L . Two equivalents of Li 2L react with both MoCl 4(THF)2 and VCl 2(tmeda) 2 yielding trimetallic sandwich compounds.
    [Show full text]
  • With Methylacetylene (CH3CCH; X(1)A1) and D4-Methylacetylene (CD
    UC Berkeley UC Berkeley Previously Published Works Title A Combined Experimental and Theoretical Study on the Formation of the 2-Methyl-1- silacycloprop-2-enylidene Molecule via the Crossed Beam Reactions of the Silylidyne Radical (SiH; X(2)Π) with Methylacetylene (CH3CCH; X(1)A1) and D4-Methylacetylene (CD... Permalink https://escholarship.org/uc/item/11x6w8jp Journal The journal of physical chemistry. A, 120(27) ISSN 1089-5639 Authors Yang, Tao Dangi, Beni B Kaiser, Ralf I et al. Publication Date 2016-07-01 DOI 10.1021/acs.jpca.5b12457 Peer reviewed eScholarship.org Powered by the California Digital Library University of California The Journal of Physical Chemistry This document is confidential and is proprietary to the American Chemical Society and its authors. Do not copy or disclose without written permission. If you have received this item in error, notify the sender and delete all copies. A Combined Experimental and Theoretical Study on the Formation of the 2-Methyl-1-silacycloprop-2-enylidene Molecule via the Crossed Beam Reactions of the Silylidyne 2 1 Radical (SiH; X Π) with Methylacetylene (CH 3CCH; X A1) and 1 D4-Methylacetylene (CD 3CCD; X A1) Journal: The Journal of Physical Chemistry Manuscript ID jp-2015-12457n.R1 Manuscript Type: Special Issue Article Date Submitted by the Author: 27-Jan-2016 Complete List of Authors: Yang, Tao; University of Hawaii at Manoa, Chemistry Dangi, Beni; University of Hawaii at Manoa, Chemistry Kaiser, Ralf; University of Hawaii at Manoa Bertels, Luke; University of California at Berkeley, Chemistry Head-Gordon, Martin; University of California, Berkeley, Chemistry ACS Paragon Plus Environment Page 1 of 32 The Journal of Physical Chemistry 1 2 3 4 A Combined Experimental and Theoretical Study on the 5 6 Formation of the 2-Methyl-1-silacycloprop-2-enylidene 7 8 Molecule via the Crossed Beam Reactions of the Silylidyne 9 2 1 10 Radical (SiH; X ΠΠΠ) with Methylacetylene (CH3CCH; X A1) 11 1 12 and D4-Methylacetylene (CD3CCD; X A1) 13 14 15 16 17 Tao Yang, Beni B.
    [Show full text]
  • Preparation, Structural Studies and Chemical Properties of New Hypervalent Iodine Compounds
    PREPARATION, STRUCTURAL STUDIES AND CHEMICAL PROPERTIES OF NEW HYPERVALENT IODINE COMPOUNDS A THESIS SUBMITTED TO THE FACULTY OF UNIVERSITY OF MINNESOTA BY ANDREY VIKTOROVICH MASKAEV IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE Advised by Dr. Viktor Zhdankin August 2013 © Andrey Viktorovich Maskaev 2013 ACKNOWLEDGEMENTS First of all, I want to thank the entire University of Minnesota Duluth and its Department of Chemistry and Biochemistry for giving me the opportunity of Graduate studies. It will stay in my memories for the rest of my life. I am especially thankful to Dr. Viktor V. Zhdankin for being my advisor, for his extremely knowledge of chemistry and for being patient with me, as well as for all his help with chemistry and any other things. I want to thank Dr. Mekhman S. Yusubov, the long-time collaborator of Dr. V.V. Zhdankin for his help with chemistry. I am deeply thankful to former and current members of Dr. Zhdankin’s research group; many of them became my good friends beside the University: Matt Luedtke, Ben Mattila, Chris Banek, Brent Kastern and Kyle Middleton for being my English language teachers; Dr. Akira Yoshimura for his readiness to help with research and being an amazing friend; Jon Fuchs, Patricia Westergren and Steve Koski, who started their work with me and gave me fantastic experience of being a research co-advisor. Many thanks to Dr. Victor N. Nemykin for his collaboration: he has provided all the X-Ray crystallography experimental data for our researches, as long as has performed theoretical calculations for our projects.
    [Show full text]
  • The Chemistry of Β-Diketiminate-Supported Boron, Aluminum
    Copyright By Dragoslav Vidović 2007 The Dissertation Committee for Dragoslav Vidović certifies that this is the approved version of the following dissertation: The Chemistry of β-Diketiminate-Supported Boron, Aluminum, Gallium and Phosphorus Compounds Committee: ___________________________ Alan H. Cowley, Supervisor ___________________________ Richard A. Jones ___________________________ Bradley J. Holliday ___________________________ Ben A. Shoulders ___________________________ Jason A. C. Clyburne 3 The Chemistry of β-Diketiminate-Supported Boron, Aluminum, Gallium and Phosphorus Compounds by Dragoslav Vidović, B.S. Dissertation Presented to the Faculty of the Graduate School of The University of Texas at Austin in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy The University of Texas at Austin May 2007 2 Dedicated to: my Father, mother and brother for endless love and support Посвећено: мом Оцу, мајци и брату на бескрајној љубави и подршци 4 Acknowledgements First and foremost, I would like to thank Professor Alan H. Cowley for not hesitating even for a moment to accept me as a part of his research group. His endless knowledge, insights, instructions and enthusiasm are truly inspirational. All of the Cowley group members with whom I had the privilege to work certainly played an important role in my achievement. Thus, I would like to thank Dr. Jeffery Pietryga, Silvia Filliponi, Lucille Mullins, Zheng Lu, Dr. Christopher Entwisltle, Dr. Leonardo Apostolico, Kalyan Vasudevan, Clint Hoberg and Adam Powell. The toughest times are usually at the beginning but Dr. Piyush Shukla’s help and guidance eased lots of those first jitters and concerns when I joined the Cowley group. Special thanks go to Dr.
    [Show full text]
  • Hydroxo Complex with Amino- Boranes: Formation of Boroxide Derivatives Antonio Antiñolo,†,* Miguel A
    Reactions of an Osmium(IV)-Hydroxo Complex with Amino- Boranes: Formation of Boroxide Derivatives Antonio Antiñolo,†,* Miguel A. Esteruelas,‡,* Cristina García-Yebra,‡,§ Jaime Martín,‡ Enrique Oñate,‡ and Alberto Ramos† †Departamento de Química Inorgánica, Orgánica y Bioquímica-Centro de Innovación en Química Avanzada (ORFEO- CINQA), Universidad de Castilla-La Mancha, Campus Universitario, E-13071 Ciudad Real, Spain ‡Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain ABSTRACT: The discovery of a reaction, which allows to prepare boroxide complexes of platinum group metals and to study 3 their behavior under CO atmosphere, is described. The trihydride-osmium(IV)-hydroxo complex OsH3(OH){κ -P,O,P- i i i [xant(P Pr2)2]} (1, xant(P Pr2)2 = 4,5-bis(diisopropylphosphino)xanthene) reacts with the amino-boranes Pr(H)NBCy2 and i 3 i Pr(H)NBBN to give the osmium(IV)-boroxide derivatives OsH3(OBR2){κ -P,O,P-[xant(P Pr2)2]} (BR2 = BCy2 (2), BBN (3); BBN i = 9-borabicyclo[3.5.1]nonane) and PrNH2, as a consequence of the addition of the O-H bond of the hydroxo ligand of 1 to the B-N bond of the amino-boranes. At room temperature, under CO atmosphere, complexes 2 and 3 eliminate H2 to afford the osmium(II)- 2 i 2 boroxide compounds OsH(OBR2)(CO)2{κ -P,P-[xant(P Pr2)2]} (BR2 = BCy2 (4), BBN (5)) bearing a κ -P,P-coordinated ether- diphosphine. The subsequent reductive elimination of the borinic acids R2BOH needs heating and long time and leads to the tricar- 2 i bonyl-osmium(0) derivative Os(CO)3{κ -P,P-[xant(P Pr2)2]} (6), with the phosphorus atoms of the diphosphine lying in the equato- rial plane of a pentagonal bypiramid of donor atoms around the metal center.
    [Show full text]
  • Publications by Alan H. Cowley
    Publications by Alan H. Cowley 1. Cowley, A. H.; Fairbrother, F.; Scott, N. "The Halides of Niobium and Tantalum, Part 5: Diethyl Ether Complexes of the Pentachlorides and Pentabromides," J. Chem. Soc., 1958, 3133. 2. Cowley, A. H.; Fairbrother, F.; Scott, N. "The Interaction of Hexamethyldisiloxane with Aluminum Halides and Iodine," J. Chem. Soc. 1959, 717. 3. Cowley, A. H.; Fairbrother, F.; Scott, N. "The Oxychlorides and Oxybromides of Niobium and Tantalum," J. Less Common. Metals, 1959, 1, 206. 4. Cowley, A. H.; Ryschkewitsch, G. E.; Sisler, H. H. "The Chemistry of Borazene, Part 3: Boron-Silicon Compounds," J. Am. Chem. Soc. 1959, 82, 501. 5. Cowley, A. H.; Cohen, S. T. "Some Evidence for a New Thioidide of Phosphorus," Inorg. Chem. 1964, 3, 780. 6. Cowley, A. H. "The Structures and Reactions of the Phosphorus Sulfides," J. Chem. Educ. 1964, 41, 530. 7. Cowley, A. H.; Cohen, S. T. "The Iodides of Phosphorus. I. Lewis Basicity and Structure," Inorg. Chem. 1965, 4, 1200. 8. Cowley, A. H.; Cohen, S. T. "The Iodides and Phosphorus. II. The Reaction of Bromine with Diphosphorus Tetraiodide," Inorg. Chem. 1965, 4, 1221. 9. Cowley, A. H.; Pinnell, R. P. "A Proton Magnetic Resonance Study of Some Dialkylamino-Phosphorus Derivatives," J. Am. Chem. Soc. 1965, 87, 4454. 10. Cowley, A. H.; Steinfink, H. "The Structure of (CH3)4P2S2," Inorg. Chem. 1965, 4, 1827. 11. Cowley, A. H. "The Chemistry of the Phosphorus-Phosphorus Bond," Chem. Rev. 1965, 65, 617. 12. Cowley, A. H.; Hnoosh, M. H. "Free Radicals Involving Phosphorus," J. Am. Chem. Soc. 1966, 88, 2595.
    [Show full text]
  • Acid–Base Free Main Group Carbonyl Analogues Ying Kai Loh and Simon Aldridge*
    Angewandte Aufstze Chemie Zitierweise: Main Group Multiple Bonds Internationale Ausgabe: doi.org/10.1002/anie.202008174 Deutsche Ausgabe: doi.org/10.1002/ange.202008174 Acid–Base Free Main Group Carbonyl Analogues Ying Kai Loh and Simon Aldridge* Stichwçrter: carbonyl compounds · main group elements · multiple bonding · oxide transfer · reactivity studies Angewandte Chemie &&&& 2020 Die Autoren. Verçffentlicht von Wiley-VCH GmbH Angew. Chem. 2020, 132,2–25 Ü Ü These are not the final page numbers! Angewandte Aufstze Chemie Main group carbonyl analogues (R2E=O) derived from p-block Aus dem Inhalt elements (E = groups 13 to 15) have long been considered as elusive species. Previously, employment of chemical tricks such as acid- and 1. Introduction 3 base-stabilization protocols granted access to these transient species in 2. Group 13 Carbonyl Analogues 5 their masked forms. However, electronic and steric effects inevitably perturb their chemical reactivity and distinguish them from classical 3. Heavier Group 14 Carbonyl carbonyl compounds. A new era was marked by the recent isolation of Analogues 11 acid–base free main group carbonyl analogues, ranging from a lighter 4. Group 15 Carbonyl Analogues 19 boracarbonyl to the heavier silacarbonyls, phosphacarbonyls and a germacarbonyl. Most importantly, their unperturbed nature elicits 5. Conclusions and Outlook 22 exciting new chemistry, spanning the vista from classical organic car- bonyl-type reactions to transition metal-like oxide ion transfer chemistry. In this Review, we survey the strategies used for the isolation be reversible due to energetically of such systems and document their emerging reactivity profiles, with favourable regeneration of the C=O a view to providing fundamental comparisons both with carbon and p bond (e.g.
    [Show full text]
  • Chemistry of N-Heterocyclic Carbene–Borane Complexes
    CHEMISTRY OF N-HETEROCYCLIC CARBENE–BORANE COMPLEXES by Andrey Solovyev B.S., Saint-Petersburg State University, St. Petersburg, Russia, 2007 Submitted to the Graduate Faculty of the Kenneth P. Dietrich School of Arts and Sciences in partial fulfillment of the requirements for the degree of Doctor of Philosophy University of Pittsburgh 2012 UNIVERSITY OF PITTSBURGH KENNETH P. DIETRICH SCHOOL OF ARTS AND SCIENCES This dissertation was presented by Andrey Solovyev It was defended on December 13, 2011 and approved by Paul E. Floreancig, Professor, Chemistry Krzysztof Matyjaszewski, Professor, Carnegie Mellon University Peter Wipf, University Professor, Chemistry Committee Chair: Dennis P. Curran, Distinguished Service Professor, Chemistry ii Copyright © by Andrey Solovyev 2012 iii CHEMISTRY OF N-HETEROCYCLIC CARBENE–BORANE COMPLEXES Andrey Solovyev, PhD University of Pittsburgh, 2012 Studies on chemistry of N-heterocyclic carbene-borane complexes (NHC-boranes), a new class of organic reagents, are reported. The radical chain mechanism of xanthate reduction with NHC-boranes has been established by the evaluation of rate constants of hydrogen abstraction, the isolation of boron-derived by-products, and EPR spectroscopic studies. NHC-BH3 complexes have been found to react with many electrophilic compounds. They reduce alkyl halides and sulfonates by an ionic mechanism. The boron products of their reactions with halogenation agents, Brønsted and Lewis acids were isolated and characterized. NHC-boryl iodide and triflate complexes undergo nucleophilic substitutions at the boron atom. In this way, a variety of substituted boranes with unusual and unprecedented structural motifs were prepared, including boryl azides, nitrosooxyborane, and nitroborane. The reaction with phenoxides in tetrahydrofuran (THF) afforded unexpected products of THF ring opening.
    [Show full text]
  • 1 CURRICULUM VITAE Alexander M. Mebel Education: Undergraduate
    CURRICULUM VITAE Alexander M. Mebel Education: Undergraduate (B.Sc., Physical Chemistry) University: Moscow Institute of Steel and Alloys (1984) Graduate (Ph.D.), Physical Chemistry Kurnakov's Institute of General and Inorganic Chemistry Russian Academy of Science, Moscow, Russia (1990) Professional Experience: 8/14-current Professor Department of Chemistry and Biochemistry Florida International University, Miami, Florida 8/10-8/14 Professor and Graduate Program Director Department of Chemistry and Biochemistry Florida International University, Miami, Florida 8/07-8/10 Associate Professor Department of Chemistry and Biochemistry Florida International University, Miami, Florida 8/03-8/07 Assistant Professor Department of Chemistry and Biochemistry Florida International University, Miami, Florida 10/01-8/03 Associate Research Fellow Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan 7/98-9/01 Assistant Research Fellow Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan 2/98-6/2000 Visiting Assistant Professor Tamkang University, Tamsui, Taiwan 1/96-6/98 Senior Academia Sinica Postdoctoral Fellow Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan 10/93-12/95 Senior Research Associate Chemistry Department, Emory University, Atlanta, Georgia, USA 8/92-9/93 Visiting scientist, special researcher Institute for Molecular Science, Okazaki, Japan. 9/91-3/92 Visiting researcher Institut für Organische Chemie Universität Erlangen-Nürnberg, Erlangen, Germany 6/87-2/93 Research worker 7/84-5/87 Engineer Laboratory of Quantum Chemistry Institute of New Chemical Problems Russian Academy of Science in Chernogolovka, Moscow, Russia 9/89-5/91 Lecturer All-Union Polytechnic Institute Moscow, Russia 1 Awards Academia Sinica Research Award for Junior Researches 2002 IAMS Outstanding Publication Award 2003 Publications Regular Articles 1.
    [Show full text]
  • Simon Aldridge (University of Oxford) Complete Publication List to June 2021
    Simon Aldridge (University of Oxford) Complete publication list to Sept 2021 4− 219. Generation of a pi-bonded isomer of [P4] by aluminyl reduction of white phosphorus and its ammonolysis to PH3 M.M.D. Roy, A. Heilmann, M. Ellwanger, S. Aldridge submitted By employing the highly reducing aluminyl complex [K{(NON)Al}]2 (NON = 4,5-bis(2,6-diisopropylanilido)-2,7-di-tert- 2− 4− butyl-9,9-dimethylxanthene), we demonstrate the controlled formation of P4 and P4 complexes from white phosphorus, and chemically reversible inter-conversion between them. The tetra-anion features a unique planar π- bonded structure, with the incorporation of the K+ cations implicit in the use of the anionic nucleophile offering 4- additional stabilization of the unsaturated isomer of the P4 fragment. This complex is extremely reactive, acting as a 3- source of P : exposure to ammonia leads to the release of phosphine (PH3) under mild conditions (room temperature and pressure), which contrast with those necessitated for the direct combination of P4 and NH3 (>5 kbar and >250°C). 218. Controlling oxidative addition and reductive elimination at Sn(I) via hemi-lability A. Caise, A.E. Crumpton, P. Vasko, J. Hicks, C. McManus, N.H. Rees, S. Aldridge submitted We report on the synthesis of a distannyne supported by a pincer ligand bearing pendant amine donors that is capable of reversibly activating E–H bonds at one or both of the tin centres through dissociation of the hemi-labile N–Sn donor/acceptor interactions. This chemistry can be exploited to sequentially (and reversibly) assemble mixed- valence chains of tin atoms of the type ArSn{Sn(Ar)H}nSnAr (n = 1, 2).
    [Show full text]