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Becerra R, Cannady JP, Walsh R. Time-resolved, Gas-phase Kinetic and Quantum Chemical Studies of the Reaction of Germylene with Hydrogen Chloride. Chemphyschem 2023; 24:e202200902. [PMID: 36806423 DOI: 10.1002/cphc.202200902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 02/15/2023] [Accepted: 02/16/2023] [Indexed: 02/23/2023]
Abstract
Time-resolved studies of germylene, GeH2 , generated by laser flash photolysis of 3,4-dimethyl-1-germacyclopent-3-ene at 193 nm and monitored by laser absorption, have been carried out to obtain rate constants for its bimolecular reaction with HCl. The reaction was studied in the gas phase, mainly at a total pressure of 10 Torr (in SF6 bath gas) at five temperatures in the range 295-558 K. Experiments at other pressures showed that these rate constants were unaffected by pressure. The second-order rate constants at 10 Torr (SF6 bath gas) fitted the Arrhenius equation: log(k/cm3 molecule-1 s-1 )=(-12.06±0.14)+(2.58±1.03 kJ mol-1 )/RTln10 where the uncertainties are single standard deviations. Quantum chemical calculations at G4 level support a mechanism in which an initial weakly bound donor-acceptor complex is formed. This can then rearrange and decompose to give H2 and HGeCl (chlorogermylene). The enthalpy barrier (36 kJ mol-1 ) is too high to allow rearrangement of the complex to GeH3 Cl (chlorogermane).
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Affiliation(s)
- Rosa Becerra
- Instituto de Quimica-Fisica 'Rocasolano' C.S.I.C., C/Serrano 119, 28006, Madrid, Spain
| | - J Pat Cannady
- Dow Chemical Company, 2030 Dow Center, Midland, MI-48674, USA
| | - Robin Walsh
- Department of Chemistry, University of Reading Whiteknights, P.O. Box 224, Reading, RG6 6AD, UK
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2
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Sinclair J, Dai G, McDonald R, Ferguson MJ, Brown A, Rivard E. Insight into the Decomposition Mechanism of Donor-Acceptor Complexes of EH 2 (E = Ge and Sn) and Access to Germanium Thin Films from Solution. Inorg Chem 2020; 59:10996-11008. [PMID: 32686404 DOI: 10.1021/acs.inorgchem.0c01492] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Electron-donating N-heterocyclic carbenes (Lewis bases, LB) and electron-accepting Lewis acids (LA) have been used in tandem to yield donor-acceptor complexes of inorganic tetrelenes LB·EH2·LA (E = Si, Ge, and Sn). Herein, we introduce the new germanium (II) dihydride adducts ImMe2·GeH2·BH3 (ImMe2 = (HCNMe)2C:) and ImiPr2Me2·GeH2·BH3 (ImiPr2Me2 = (MeCNiPr)2C:), with the former complex containing nearly 40 wt % germanium. The thermal release of bulk germanium from ImMe2·GeH2·BH3 (and its deuterated isotopologue ImMe2·GeD2·BD3) was examined in solution, and a combined kinetic and computational investigation was undertaken to probe the mechanism by which Ge is liberated. Moreover, the thermolysis of ImMe2·GeH2·BH3 in solution cleanly affords conformal nanodimensional layers of germanium as thin films of variable thicknesses (20-70 nm) on silicon wafers. We also conducted a computational investigation into potential decomposition pathways for the germanium(II)- and tin(II)-dihydride complexes NHC·EH2·BH3 (NHC = [(HCNR)2C:]; R = 2,6-iPr2C6H3 (Dipp), Me, and H; and E = Ge and Sn). Overall, this study introduces a mild and convenient solution-only protocol for the deposition of thin films of Ge, a widely used semiconductor in materials research and industry.
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Affiliation(s)
- Jocelyn Sinclair
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, Canada T6G 2G2
| | - Guoliang Dai
- School of Chemistry, Biology and Materials Engineering, Suzhou University of Science and Technology, 2215009 Suzhou, P. R. China
| | - Robert McDonald
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, Canada T6G 2G2
| | - Michael J Ferguson
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, Canada T6G 2G2
| | - Alex Brown
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, Canada T6G 2G2
| | - Eric Rivard
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, Canada T6G 2G2
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3
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Mangan RJ, Rit A, Sindlinger CP, Tirfoin R, Campos J, Hicks J, Christensen KE, Niu H, Aldridge S. Activation of Protic, Hydridic and Apolar E-H Bonds by a Boryl-Substituted Ge II Cation. Chemistry 2019; 26:306-315. [PMID: 31660651 DOI: 10.1002/chem.201904171] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Indexed: 11/07/2022]
Abstract
The synthesis of a boryl-substituted germanium(II) cation, [Ge{B(NDippCH)2 }(IPrMe)]+ , (Dipp=2,6-diisopropylphenyl) featuring a supporting N-heterocyclic carbene (NHC) donor, has been explored through chloride abstraction from the corresponding (boryl)(NHC)GeCl precursor. Crystallographic studies in the solid state and UV/Vis spectra in fluorobenzene solution show that this species dimerizes under such conditions to give [(IPrMe){(HCNDipp)2 B}Ge=Ge{B(NDippCH)2 }(IPrMe)]2+ (IPrMe = 1,3-diisopropyl-4,5-dimethylimidazolin-2-ylidene), which can be viewed as an imidazolium-functionalized digermene. The dimer is cleaved in the presence of donor solvents such as [D8 ]thf or [D5 ]pyridine, to give monomeric adducts of the type [Ge{B(NDippCH)2 }(IPrMe)(L)]+ . In the case of the thf adduct, the additional donor is shown to be sufficiently labile that it can act as a convenient in situ source of the monomeric complex [Ge{B(NDippCH)2 }(IPrMe)]+ for oxidative bond-activation chemistry. Thus, [Ge{B(NDippCH)2 }(IPrMe)(thf)]+ reacts with silanes and dihydrogen, leading to the formation of GeIV products, whereas the cleavage of the N-H bond in ammonia ultimately yields products containing C-H and B-N bonds. The facile reactivity observed in E-H bond activation is in line with the very small calculated HOMO-LUMO gap (132 kJ mol-1 ).
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Affiliation(s)
- Robert J Mangan
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR, UK
| | - Arnab Rit
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR, UK
| | - Christian P Sindlinger
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR, UK
| | - Rémi Tirfoin
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR, UK
| | - Jesús Campos
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR, UK
| | - Jamie Hicks
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR, UK
| | - Kirsten E Christensen
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR, UK
| | - Haoyu Niu
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR, UK
| | - Simon Aldridge
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR, UK
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4
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Insertion of germylenes into Ge–X bonds giving molecular oligogermanes: theory and practice. MONATSHEFTE FUR CHEMIE 2019. [DOI: 10.1007/s00706-019-02495-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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5
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Becerra R, Walsh R. Thermochemistry of germanium and organogermanium compounds. Phys Chem Chem Phys 2019; 21:988-1008. [DOI: 10.1039/c8cp06208k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
This article reviews the current state of thermochemistry (enthalpies of formation) of germanium and organogermanium compounds.
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Affiliation(s)
- Rosa Becerra
- Instituto de Quimica-Fisica ‘Rocasolano’
- C.S.I.C
- 28006 Madrid
- Spain
| | - Robin Walsh
- School of Chemistry
- University of Reading
- Reading
- UK
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6
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Chu T, Nikonov GI. Oxidative Addition and Reductive Elimination at Main-Group Element Centers. Chem Rev 2018; 118:3608-3680. [DOI: 10.1021/acs.chemrev.7b00572] [Citation(s) in RCA: 342] [Impact Index Per Article: 57.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Terry Chu
- Department of Chemistry, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario L2S 3A1, Canada
| | - Georgii I. Nikonov
- Department of Chemistry, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario L2S 3A1, Canada
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Abstract
This Review article deals with the synthesis and properties of inorganic hydrocarbon analogues: binary chemical species that contain heavier Group 14 elements (Si, Ge, Sn or Pb) and hydrogen as components. Rapid advances in our general knowledge of these species have enabled the development of industrially relevant processes such as the hydrosilylation of unsaturated substrates and the chemical vapor deposition of semi-conducting films.
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Affiliation(s)
- Eric Rivard
- Department of Chemistry
- University of Alberta
- Edmonton
- Canada
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8
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Su MD. Excited-State Photolytic Mechanism of Cyclopentene Containing a Group 14 Element: An MP2-CAS//CASSCF Study. J Phys Chem A 2015. [PMID: 26204240 DOI: 10.1021/acs.jpca.5b04304] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The potential energy surfaces corresponding to the photolytic reactions of 1,2-dimethyl-cyclopentene, 3,4-dimethyl-silacyclopent-3-ene, and 3,4-dimethyl-germacyclopent-3-ene were investigated by employing the CAS(6,6)/6-311G(d) and MP2-CAS-(6,6)/6-311++G(3df,3pd)//CAS(6,6)/6-311G(d) methods. Also, six kinds of substituted germacyclopent-3-ene were used as model reactants by way of the CASSCF and MP2-CAS methods to study their photolytic mechanisms. The theoretical findings indicate that the photolysis of the above reactants all adopt the same reaction path as follows: reactant → Franck-Condon region → conical intersection → germylene and 1,3-butadiene. However, the theoretical results demonstrate that no photolysis ((1)(π →π*)) can be observed in the 1,2-dimethyl-cyclopentene system. Above all, the theoretical investigations strongly suggest that both steric effects, originating from the bulky substituents, and the atomic radius of the group 14 element (C, Si, and Ge) play a crucial role in determining the cis/trans selectivity of the conformation of 1,3-butadiene during their photolytic reactions.
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Affiliation(s)
- Ming-Der Su
- †Department of Applied Chemistry, National Chiayi University, Chiayi 60004, Taiwan.,‡Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
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9
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Becerra R, Cannady JP, Walsh R. Reaction of Germylene with Sulfur Dioxide: Gas-Phase Kinetic and Theoretical Studies. Organometallics 2014. [DOI: 10.1021/om500842v] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Rosa Becerra
- Instituto
de Quimica-Fisica “Rocasolano”, CSIC, C/Serrano 119, 28006 Madrid, Spain
| | - J. Pat Cannady
- Dow Corning Corporation, 2200 West Salzburg Road, Midland, Michigan 48641, United States
| | - Robin Walsh
- Department
of Chemistry, University of Reading, Whiteknights, P.O. Box 224, Reading RG6 6AD, U.K
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10
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Su MD, Chu SY. Theoretical Study of the Germylene Insertion Reaction into the A-H Bond of First-Row and Second-Row AHn Hydrides. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.200000015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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11
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Boganov SE, Promyslov VM, Faustov VI, Egorov MP, Nefedov OM. Quantum chemical study of interactions of carbenes and their analogs of the EH2 and EHX types (E = Si, Ge, Sn; X = F, Cl, Br) with HX and H2, respectively: the insertion and substituent exchange reactions. Russ Chem Bull 2012. [DOI: 10.1007/s11172-011-0333-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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12
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Billone PS, Beleznay K, Harrington CR, Huck LA, Leigh WJ. A Glimpse at the Chemistry of GeH2 in Solution. Direct Detection of an Intramolecular Germylene–Alkene π-Complex. J Am Chem Soc 2011; 133:10523-34. [PMID: 21639137 DOI: 10.1021/ja201190b] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Paul S. Billone
- Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, ON Canada L8S 4M1
| | - Katie Beleznay
- Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, ON Canada L8S 4M1
| | - Cameron R. Harrington
- Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, ON Canada L8S 4M1
| | - Lawrence A. Huck
- Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, ON Canada L8S 4M1
| | - William J. Leigh
- Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, ON Canada L8S 4M1
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13
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Bundhun A, Blowers P, Ramasami P, Schaefer III HF. Quantum Mechanical Modeling for the GeX 2/GeHX + GeH 4 Reactions (X = H, F, Cl, and Br). J Phys Chem A 2010; 114:4210-23. [DOI: 10.1021/jp1006389] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Ashwini Bundhun
- Department of Chemistry, University of Mauritius, Réduit, Mauritius, Department of Chemical and Environmental Engineering, The University of Arizona, Tucson, Arizona 85721, and Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602
| | - Paul Blowers
- Department of Chemistry, University of Mauritius, Réduit, Mauritius, Department of Chemical and Environmental Engineering, The University of Arizona, Tucson, Arizona 85721, and Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602
| | - Ponnadurai Ramasami
- Department of Chemistry, University of Mauritius, Réduit, Mauritius, Department of Chemical and Environmental Engineering, The University of Arizona, Tucson, Arizona 85721, and Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602
| | - Henry F. Schaefer III
- Department of Chemistry, University of Mauritius, Réduit, Mauritius, Department of Chemical and Environmental Engineering, The University of Arizona, Tucson, Arizona 85721, and Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602
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14
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Epping JD, Yao S, Karni M, Apeloig Y, Driess M. Si═X Multiple Bonding with Four-Coordinate Silicon? Insights into the Nature of the Si═O and Si═S Double Bonds in Stable Silanoic Esters and Related Thioesters: A Combined NMR Spectroscopic and Computational Study. J Am Chem Soc 2010; 132:5443-55. [DOI: 10.1021/ja1004812] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Jan. D. Epping
- Institute of Chemistry, Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 135, Sekr. C2, D-10623 Berlin, Germany and Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Shenglai Yao
- Institute of Chemistry, Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 135, Sekr. C2, D-10623 Berlin, Germany and Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Miriam Karni
- Institute of Chemistry, Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 135, Sekr. C2, D-10623 Berlin, Germany and Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Yitzhak Apeloig
- Institute of Chemistry, Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 135, Sekr. C2, D-10623 Berlin, Germany and Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Matthias Driess
- Institute of Chemistry, Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 135, Sekr. C2, D-10623 Berlin, Germany and Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion - Israel Institute of Technology, Haifa 32000, Israel
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15
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Becerra R, Walsh R. Time-resolved gas-phase kinetic study of the germylene addition reaction, GeH2 + C2D2. Phys Chem Chem Phys 2010; 12:2923-8. [DOI: 10.1039/b922506d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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16
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Becerra R, Walsh R. Time-resolved gas-phase kinetic study of the germylene addition reaction, GeH2 + CH3CCCH3. Phys Chem Chem Phys 2009; 11:3539-46. [DOI: 10.1039/b821330e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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17
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Thimer KC, Al-Rafia SMI, Ferguson MJ, McDonald R, Rivard E. Donor/acceptor stabilization of Ge(ii) dihydride. Chem Commun (Camb) 2009:7119-21. [DOI: 10.1039/b915950a] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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18
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Gopakumar G, Ngan VT, Lievens P, Nguyen MT. Electronic Structure of Germanium Monohydrides GenH, n = 1−3. J Phys Chem A 2008; 112:12187-95. [DOI: 10.1021/jp805173n] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- G. Gopakumar
- Department of Chemistry, Laboratory of Solid State Physics and Magnetism, and Institute for Nanoscale Physics and Chemistry (INPAC), University of Leuven, B-3001 Leuven, Belgium
| | - Vu Thi Ngan
- Department of Chemistry, Laboratory of Solid State Physics and Magnetism, and Institute for Nanoscale Physics and Chemistry (INPAC), University of Leuven, B-3001 Leuven, Belgium
| | - Peter Lievens
- Department of Chemistry, Laboratory of Solid State Physics and Magnetism, and Institute for Nanoscale Physics and Chemistry (INPAC), University of Leuven, B-3001 Leuven, Belgium
| | - Minh Tho Nguyen
- Department of Chemistry, Laboratory of Solid State Physics and Magnetism, and Institute for Nanoscale Physics and Chemistry (INPAC), University of Leuven, B-3001 Leuven, Belgium
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19
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Becerra R, Boganov SE, Egorov MP, Faustov VI, Krylova IV, Nefedov OM, Promyslov VM, Walsh R. Surprisingly Slow Reaction of Dimethylsilylene with Dimethylgermane: Time-Resolved Kinetic Studies and Related Quantum Chemical Calculations. J Phys Chem A 2008; 112:849-57. [DOI: 10.1021/jp710740a] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Rosa Becerra
- Instituto de Quimica-Fisica “Rocasolano”, C.S.I.C., C/Serrano 119, 28006 Madrid, Spain
| | - Sergey E. Boganov
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 47, 119991 Moscow, Russian Federation
| | - Mikhail P. Egorov
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 47, 119991 Moscow, Russian Federation
| | - Valery I. Faustov
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 47, 119991 Moscow, Russian Federation
| | - Irina V. Krylova
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 47, 119991 Moscow, Russian Federation
| | - Oleg M. Nefedov
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 47, 119991 Moscow, Russian Federation
| | - Vladimir M. Promyslov
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 47, 119991 Moscow, Russian Federation
| | - Robin Walsh
- Department of Chemistry, University of Reading, Whiteknights, P. O. Box 224, Reading RG6 6AD, U.K
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20
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Smirnov VN. Germane decomposition: Kinetic and thermochemical data. KINETICS AND CATALYSIS 2007. [DOI: 10.1134/s0023158407050023] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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21
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Becerra R, Boganov SE, Egorov MP, Krylova IV, Nefedov OM, Walsh R. Direct Time-Resolved Study of the Gas-Phase Reactions of Germylene with Ethyl- and Diethylgermane: Absolute Rate Constants, Temperature Dependences, and Mechanism. J Phys Chem A 2007; 111:1434-40. [PMID: 17279735 DOI: 10.1021/jp0661948] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Time-resolved studies of germylene, GeH2, generated by the 193 nm laser flash photolysis of 3,4-dimethyl-1-germacyclopent-3-ene, have been carried out to obtain rate constants for its bimolecular reactions with ethyl- and diethylgermanes in the gas phase. The reactions were studied over the pressure range 1-100 Torr with SF6 as bath gas and at five temperatures in the range 297-564 K. Only slight pressure dependences were found for GeH2 + EtGeH3 (399, 486, and 564 K). The high pressure rate constants gave the following Arrhenius parameters: for GeH2 + EtGeH3, log A = -10.75 +/- 0.08 and Ea = -6.7 +/- 0.6 kJ mol-1; for GeH2 + Et2GeH2, log A = -10.68 +/- 0.11 and Ea = -6.95 +/- 0.80 kJ mol-1. These are consistent with fast, near collision-controlled, association processes at 298 K. RRKM modeling calculations are, for the most part, consistent with the observed pressure dependence of GeH2 + EtGeH3. The ethyl substituent effects have been extracted from these results and are much larger than the analogous methyl substituent effects in the SiH2 + methylsilane reaction series. This is consistent with a mechanistic model for Ge-H insertion in which the intermediate complex has a sizable secondary barrier to rearrangement.
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Affiliation(s)
- Rosa Becerra
- Instituto de Quimica-Fisica Rocasolano, CSIC, C/Serrano 119, 28006 Madrid, Spain
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22
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Becerra R, Walsh R. What have we learnt about heavy carbenes through laser flash photolysis studies? Phys Chem Chem Phys 2007; 9:2817-35. [PMID: 17538727 DOI: 10.1039/b617844h] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Time resolved gas-phase kinetic studies have contributed a great deal of fundamental information about the reactions and reactivity of heavy carbenes (silylenes, germylenes and stannylenes) during the past two decades. In this article we trace the development of our understanding through the mechanistic themes of intermediate complexes, third body assisted associations, catalysed reactions, non-observed reactions and substituent effects. Ab initio (quantum chemical) calculations have substantially assisted mechanistic interpretation and are discussed where appropriate. Trends in reactivity are identified and some signposts to future studies are indicated. This review, although detailed, is not comprehensive.
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Affiliation(s)
- Rosa Becerra
- Instituto Quimica-Fisica Rocasolano, CSIC, C/Serrano 119, 28006, Madrid, Spain
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23
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Becerra R, Boganov SE, Egorov MP, Faustov VI, Krylova IV, Nefedov OM, Promyslov VM, Walsh R. A comparison of the reactivity of germylene and dimethylgermylene with some methylgermanes. Direct kinetic and quantum chemical studies. Phys Chem Chem Phys 2007; 9:4395-406. [PMID: 17687486 DOI: 10.1039/b706148j] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Time-resolved studies of germylene, GeH(2), and dimethygermylene, GeMe(2), generated by the 193 nm laser flash photolysis of appropriate precursor molecules have been carried out to try to obtain rate coefficients for their bimolecular reactions with dimethylgermane, Me(2)GeH(2), in the gas-phase. GeH(2) + Me(2)GeH(2) was studied over the pressure range 1-100 Torr with SF(6) as bath gas and at five temperatures in the range 296-553 K. Only slight pressure dependences were found (at 386, 447 and 553 K). RRKM modelling was carried out to fit these pressure dependences. The high pressure rate coefficients gave the Arrhenius parameters: log(A/cm(3) molecule(-1) s(-1)) = -10.99 +/- 0.07 and E(a) =-(7.35 +/- 0.48) kJ mol(-1). No reaction could be found between GeMe(2) + Me(2)GeH(2) at any temperature up to 549 K, and upper limits of ca. 10(-14) cm(3) molecule(-1) s(-1) were set for the rate coefficients. A rate coefficient of (1.33 +/- 0.04) x 10(-10) cm(3) molecule(-1) s(-1) was also obtained for GeH(2) + MeGeH(3) at 296 K. No reaction was found between GeMe(2) and MeGeH(3). Rate coefficient comparisons showed, inter alia, that in the substrate germane Me-for-H substitution increased the magnitudes of rate coefficients significantly, while in the germylene Me-for-H substitution decreased the magnitudes of rate coefficients by at least four orders of magnitude. Quantum chemical calculations (G2(MP2,SVP)//B3LYP level) supported these findings and showed that the lack of reactivity of GeMe(2) is caused by a positive energy barrier for rearrangement of the initially formed complexes. Full details of the structures of intermediate complexes and the discussion of their stabilities are given in the paper.
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Affiliation(s)
- Rosa Becerra
- Instituto de Quimica-Fisica Rocasolano, Consejo Superior de Investigaciones Científicas, C/Serrano 119, 28006 Madrid, Spain
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Becerra R, Harrington CR, Leigh WJ, Kefala LA, Walsh R. First Detection of Methylgermylene in the Gas Phase and Time-Resolved Study of Some of Its Reactions. Organometallics 2006. [DOI: 10.1021/om0601798] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Rosa Becerra
- Instituto de Quimica-Fisica ‘Rocasolano', CSIC, C/Serrano 119, 28006 Madrid, Spain
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Antoniotti P, Borocci S, Grandinetti F. Ge3H(n)- anions (n = 0-5) and their neutral analogues: a theoretical investigation on the structure, stability, and thermochemistry. J Phys Chem A 2006; 110:9429-37. [PMID: 16869693 DOI: 10.1021/jp0614603] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The structure, stability, and thermochemistry of various Ge3H(n)- isomers (n = 0-5) and of their neutral analogues have been investigated at the B3LYP/6-311+G(d), MP2(full)/6-31G(d), and Gaussian-2 (G2) level of theory. For Ge3H(-), both the B3LYP and the G2/MP2 methods predict the cyclic, H-bridged structure 1a- as the global minimum, more stable than another cyclic isomer and an open-chain isomer by ca. 10 and 25 kcal mol(-1), respectively. For Ge3H2(-), the B3LYP and the G2/MP2 methods provide a somewhat different description of the potential energy surface. At the G2/MP2 level of theory, the global minimum is the cyclic, H2Ge-bridged structure 2a-, separated by other three nearly degenerate isomers by ca. 10 kcal mol(-1). On the other hand, at the B3LYP level of theory, the cyclic, H-bridged structure 2e-, not located at the MP2 level of theory, is more stable than 2a- by ca. 1 kcal mol(-1). For Ge3H3(-), both the B3LYP and the G2/MP2 methods predict the cyclic, H3Ge-bridged isomer 3a- as the global minimum, but the energy differences with the other five located isomeric structures predicted by the two methods are quantitatively different. Similar to Ge3H2(-), the B3LYP and the G2/MP2 theoretical levels provide a somewhat different description of the Ge3H4(-) potential energy surface. At the G2/MP2 level of theory, the global minimum is the cyclic structure 4b- of C(2v) symmetry, featuring a Ge2H4 moiety and a Ge-bridged atom, which is more stable than other three located isomers by 3, 9, and 17 kcal mol(-1). On the other hand, at the B3LYP level of theory, the open-chain isomer 4a- of H3Ge-Ge-GeH(-) connectivity is more stable than 4b- by ca. 1 kcal mol(-1) and nearly degenerate with the alternative open-chain isomer H3Ge-GeH-Ge(-). For Ge3H5(-), both the B3LYP and the G2/MP2 methods predict the 2-propenyl-like isomer H3Ge-Ge-GeH2(-) as the global minimum, with energy differences with other four isomeric structures which range from ca. 1-2 to 13-17 kcal mol(-1). At the G2 level of theory and 298.15 K, the electron affinities of Ge3H(n) are computed as 2.17 (n = 0), 2.57 (n = 1), 1.70 (n = 2), 2.41 (n = 3), 2.07/1.80 (n = 4), and 2.71/2.46 eV (n = 5). The two alternative values reported for Ge3H4 and Ge3H5 reflect the alternative conceivable choice for the structure of the involved neutrals and ions. The G2 enthalpies of formation of Ge3H(n) and Ge3H(n)- (n = 0-5) have also been calculated using the atomization procedure. Finally, we have briefly discussed the implications of our calculations for previously performed mass spectrometric experiments on the negative ion chemistry of GeH4.
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Affiliation(s)
- Paola Antoniotti
- Dipartimento di Chimica Generale ed Organica Applicata, Università degli Studi di Torino, C.so M. D' Azeglio, 48, 10125 Torino, Italy.
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Krummenacher I, Breher F. Two Different Products Observed in the Reaction of a Bis(germylene) with Molybdenum Hydride [Mo(H)Cp(CO)3]. Z Anorg Allg Chem 2006. [DOI: 10.1002/zaac.200500503] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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27
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Leigh WJ, Lollmahomed F, Harrington CR. Time-Resolved Spectroscopic Studies of the Reactivities of Dimethylgermylene and Tetramethyldigermene in Solution. Organometallics 2006. [DOI: 10.1021/om0600083] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- William J. Leigh
- Department of Chemistry, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4M1
| | - Farahnaz Lollmahomed
- Department of Chemistry, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4M1
| | - Cameron R. Harrington
- Department of Chemistry, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4M1
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Becerra R, Gaspar PP, Harrington CR, Leigh WJ, Vargas-Baca I, Walsh R, Zhou D. Direct detection of dimethylstannylene and tetramethyldistannene in solution and the gas phase by laser flash photolysis of 1,1-dimethylstannacyclopent-3-enes. J Am Chem Soc 2006; 127:17469-78. [PMID: 16332099 DOI: 10.1021/ja052675d] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The photochemistry of 1,1-dimethyl- and 1,1,3,4-tetramethylstannacyclopent-3-ene (4a and 4b, respectively) has been studied in the gas phase and in hexane solution by steady-state and 193-nm laser flash photolysis methods. Photolysis of the two compounds results in the formation of 1,3-butadiene (from 4a) and 2,3-dimethyl-1,3-butadiene (from 4b) as the major products, suggesting that cycloreversion to yield dimethylstannylene (SnMe2) is the main photodecomposition pathway of these molecules. Indeed, the stannylene has been trapped as the Sn-H insertion product upon photolysis of 4a in hexane containing trimethylstannane. Flash photolysis of 4a in the gas phase affords a transient absorbing in the 450-520-nm range that is assigned to SnMe2 by comparison of its spectrum and reactivity to those previously reported from other precursors. Flash photolysis of 4b in hexane solution affords results consistent with the initial formation of SnMe2 (lambda(max) approximately 500 nm), which decays over approximately 10 micros to form tetramethyldistannene (5b; lambda(max) approximately 470 nm). The distannene decays over the next ca. 50 micros to form at least two other longer-lived species, which are assigned to higher SnMe2 oligomers. Time-dependent DFT calculations support the spectral assignments for SnMe2 and Sn2Me4, and calculations examining the variation in bond dissociation energy with substituent (H, Me, and Ph) in disilenes, digermenes, and distannenes rule out the possibility that dimerization of SnMe2 proceeds reversibly. Addition of methanol leads to reversible reaction with SnMe2 to form a transient absorbing at lambda(max) approximately 360 nm, which is assigned to the Lewis acid-base complex between SnMe2 and the alcohol.
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Affiliation(s)
- Rosa Becerra
- Instituto de Quimica-Fisica Rocasolano, C.S.I.C., C/Serrano 119, 28006 Madrid, Spain
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Becerra R, Boganov S, Egorov M, Krylova I, Nefedov O, Walsh R. Direct detection of chlorosilylene and time resolved study of some of its reactions in the gas-phase using a new photochemical precursor. Chem Phys Lett 2005. [DOI: 10.1016/j.cplett.2005.07.079] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Leigh WJ, Harrington CR. Di- and Trivalent Organogermanium Reactive Intermediates. Kinetics and Mechanisms of Some Reactions of Diphenylgermylene and Tetraphenyldigermene in Solution. J Am Chem Soc 2005; 127:5084-96. [PMID: 15810843 DOI: 10.1021/ja043072p] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reactivity of diphenylgermylene (Ph2Ge) with several classes of germylene scavengers has been studied in hexane solution at 23 degrees C by laser flash photolysis of 3,4-dimethyl-1,1-diphenyl-1-germacyclopent-3-ene (1a), a clean and highly efficient precursor to the germylene and its dimer, tetraphenyldigermene (2a). The reactions studied include M-H insertion reactions with Group 14 hydrides (M = Si, Ge, Sn), halogen atom abstractions from bromo- and chlorocarbons, Lewis acid-base complexation with 1 degrees, 2 degrees, and 3 degrees aliphatic amines, and reaction with an aliphatic alkene, alkyne and diene, and oxygen. Absolute rate constants for (irreversible) scavenging of the germylene could be obtained by direct measurement of the germylene decay kinetics for all but the least efficient scavengers (triethylsilane, oxygen, chloroform, and 1-bromopentane), for which estimates of the rate constants were obtained by Stern-Volmer analysis of the reduction in digermene yield as a function of scavenger concentration. Distinctly different kinetic behavior is observed for scavenging of Ph2Ge by isoprene, 4,4-dimethyl-1-pentene, and triethylamine; in these cases, the results suggest that reaction is rapid (k(Q) = 3-6 x 10(9) M(-1)s(-1)) but reversible (K(eq) = 2500 - ca. 20,000 M(-1)) over the range of scavenger concentrations studied. The reactions with the C-C unsaturated compounds proceed via the intermediacy of long-lived transient species absorbing at <290 nm, which are tentatively assigned to the corresponding three-membered germanocycles on the basis of their UV spectra and lifetimes. Upper limits for the absolute rate constants for reaction of tetraphenyldigermene (2a) toward many of these reagents are also reported.
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Affiliation(s)
- William J Leigh
- Department of Chemistry, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4M1.
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Boganov SE, Egorov MP, Faustov VI, Krylov IV, Nefedov OM, Becerra R, Walsh R. Gas phase kinetic and theoretical studies of reactions of germylenes and dimethylstannylene. Russ Chem Bull 2005. [DOI: 10.1007/s11172-005-0285-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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32
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Lemierre V, Chrostowska A, Dargelos A, Baylère P, Leigh WJ, Harrington CR. Flash vacuum thermolysis of 3,4-dimethyl-1-germacyclopent-3-enes: UV photoelectron spectroscopic characterization of GeH2and GeMe2. Appl Organomet Chem 2004. [DOI: 10.1002/aoc.628] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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33
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Leigh WJ, Harrington CR, Vargas-Baca I. Organogermanium Reactive Intermediates. The Direct Detection and Characterization of Transient Germylenes and Digermenes in Solution. J Am Chem Soc 2004; 126:16105-16. [PMID: 15584746 DOI: 10.1021/ja046308y] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Diphenylgermylene (Ph2Ge) and its Ge=Ge doubly bonded dimer, tetraphenyldigermene (6a), have been characterized directly in solution for the first time by laser flash photolysis methods. The germylene is formed via (formal) cheletropic photocycloreversion of 3,4-dimethyl-1,1-diphenylgermacyclopent-3-ene (4a), which is shown to proceed in high chemical (>95%) and quantum yield (phi = 0.62) by steady-state trapping experiments with methanol, acetic acid, isoprene, and triethylsilane. Flash photolysis of 4a in dry deoxygenated hexane at 23 degrees C leads to the prompt formation of a transient assigned to Ph2Ge (lambda(max) = 500 nm; epsilon(max) = 1650 M(-1) cm(-1)), which decays with second-order kinetics (tau approximately 3 micros), with the concomitant growth of a second transient species that is assigned to digermene 6a (tau approximately 40 micros; lambda(max) = 440 nm). Analogous results are obtained from 1,1-dimesityl- and 1,1-dimethyl-3,4-dimethylgermacyclopent-3-ene (4b and 4c, respectively), which afford Mes2Ge (tau approximately 20 micros; lambda(max) = 560 nm) and Me2Ge (tau approximately 2 micros; lambda(max) = 480 nm), respectively, as well as the corresponding digermenes, tetramesityl- (6b; lambda(max) = 410 nm) and tetramethyldigermene (6c; lambda(max) = 370 nm). The results for the mesityl compound are compared to the analogous ones from laser flash photolysis of the known Mes2Ge/6b precursor, hexamesitylcyclotrigermane. The spectra of the three germylenes and two of the digermenes are in excellent agreement with calculated spectra, derived from time-dependent DFT calculations. Absolute rate constants for dimerization of Ph2Ge and Mes2Ge and for their reaction with n-butylamine and acetic acid in hexane at 23 degrees C are also reported.
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Affiliation(s)
- William J Leigh
- Department of Chemistry, McMaster University, 1280 Main Street West, Hamilton, ON Canada L8S 4M1.
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34
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Becerra R, Boganov SE, Egorov MP, Faustov VI, Krylova IV, Nefedov OM, Promyslov VM, Walsh R. An investigation of the germylene addition reaction, GeH2 + C2H2: Time-resolved gas-phase kinetic studies and quantum chemical calculations of the reaction energy surface. Phys Chem Chem Phys 2004. [DOI: 10.1039/b316465a] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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35
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Becerra R, Cannady JP, Walsh R. Investigation of the Prototype Silylene Reaction, SiH2 + H2O (and D2O): Time-Resolved Gas-Phase Kinetic Studies, Isotope Effects, RRKM Calculations, and Quantum Chemical Calculations of the Reaction Energy Surface. J Phys Chem A 2003. [DOI: 10.1021/jp036431w] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Rosa Becerra
- Instituto de Quimica-Fisica “Rocasolano”, C.S.I.C., C/Serrano 119, 28006 Madrid, Spain
| | - J. Pat Cannady
- Dow Corning Corporation, P.O. Box 995, Mail 128, Midland, Michigan 48686-0995
| | - Robin Walsh
- Department of Chemistry, University of Reading, Whiteknights, P.O. Box 224, Reading, RG6 6AD United Kingdom
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36
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Becerra R, Boganov SE, Egorov MP, Faustov VI, Krylova IV, Nefedov OM, Walsh R. First gas-phase detection of dimethylstannylene and time-resolved study of some of its reactions. J Am Chem Soc 2002; 124:7555-62. [PMID: 12071766 DOI: 10.1021/ja012691k] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Using a laser flash photolysis/laser probe technique, we report the observation of strong absorption signals in the wavelength region 450-520 nm (highest intensity at 514.5 nm) from four potential precursors of dimethylstannylene, SnMe(2), subjected to 193 nm UV pulses. From GC analyses of the gaseous products, combined with quantum chemical excited state CIS and TD calculations, we can attribute these absorptions largely to SnMe(2), with SnMe(4) as the cleanest source of the species. Kinetic studies have been carried out by time-resolved monitoring of SnMe(2). Rate constants have been measured for its reactions with 1,3-C(4)H(6), MeC[triple bond]CMe, MeOH, 1-C(4)H(9)Br, HCl, and SO(2). No evidence could be found for reaction of SnMe(2) with C(2)H(4), C(3)H(8), Me(3)SiH, GeH(4), Me(2)GeH(2), or N(2)O. Limits of less than 10(-13) cm(3) molecule(-1) s(-1) were set for the rate constants for these latter reactions. These measurements showed that SnMe(2) does not insert readily into C-H, Si-H, Ge-H, C-C, Si-C, or Ge-C bonds. It is also unreactive with alkenes although not with dienes or alkynes. It is selectively reactive with lone pair donor molecules. The possible mechanisms of these reactions are discussed. These results represent the first visible absorption spectrum and rate constants for any organo-stannylene in the gas phase.
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Affiliation(s)
- Rosa Becerra
- Instituto de Quimica-Fisica Rocasolano, C.S.I.C., C/Serrano 119, 28006 Madrid, Spain
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Wang X, Andrews L, Kushto GP. Infrared Spectra of the Novel Ge2H2 and Ge2H4 Species and the Reactive GeH1,2,3 Intermediates in Solid Neon, Deuterium and Argon. J Phys Chem A 2002. [DOI: 10.1021/jp020219v] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xuefeng Wang
- Department of Chemistry, P. O. Box 400319, University of Virginia, Charlottesville, Virginia 22904-4319
| | - Lester Andrews
- Department of Chemistry, P. O. Box 400319, University of Virginia, Charlottesville, Virginia 22904-4319
| | - Gary P. Kushto
- Department of Chemistry, P. O. Box 400319, University of Virginia, Charlottesville, Virginia 22904-4319
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39
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Acker J, Bohmhammel K. Reactivity of Intermetallic Compounds: A Solid State Approach to Direct Reactions of Silicon. J Phys Chem B 2002. [DOI: 10.1021/jp0130315] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jörg Acker
- Princeton University, Department of Chemistry, Princeton, New Jersey 08544, and Freiberg University of Mining and Technology, Department of Physical Chemistry, D-09599 Freiberg, Germany
| | - Klaus Bohmhammel
- Princeton University, Department of Chemistry, Princeton, New Jersey 08544, and Freiberg University of Mining and Technology, Department of Physical Chemistry, D-09599 Freiberg, Germany
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Becerra R, Egorov MP, Krylova IV, Nefedov OM, Walsh R. Absolute rate constants for the reactions of germylene and dimethylgermylene with dimethylgermane: the deactivating effect of methyl groups in heavy carbenes. Chem Phys Lett 2002. [DOI: 10.1016/s0009-2614(01)01257-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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41
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Becerra R, Boganov SE, Egorov MP, Faustov VI, Promyslov VM, Nefedov OM, Walsh R. An investigation of the prototype germylene addition reaction, GeH2 + C2H4: Time-resolved gas-phase kinetic studies and quantum chemical calculations of the reaction energy surface. Phys Chem Chem Phys 2002. [DOI: 10.1039/b206180e] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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42
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Becerra R, Walsh R. Time-resolved gas-phase kinetic study of the germylene addition reaction, GeH2 + C2D4, as a function of temperature and pressure: isotope effects and mechanistic complexities. Phys Chem Chem Phys 2002. [DOI: 10.1039/b207592j] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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43
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Becerra R, Walsh R. Time-resolved gas-phase kinetic study of the reaction of germylene with propene over the temperature range 293–415 K: the thermal stabilities of germiranes. J Organomet Chem 2001. [DOI: 10.1016/s0022-328x(01)00839-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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44
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Aldridge S, Downs AJ. Hydrides of the main-group metals: new variations on an old theme. Chem Rev 2001; 101:3305-65. [PMID: 11840988 DOI: 10.1021/cr960151d] [Citation(s) in RCA: 278] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- S Aldridge
- Department of Chemistry, Cardiff University, P.O. Box 912, Park Place, Cardiff CF10 3TB, United Kingdom
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45
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Miller KA, Watson TW, Bender JE, Banaszak Holl MM, Kampf JW. Intermolecular C-H insertions and cyclization reactions involving a stable germylene. J Am Chem Soc 2001; 123:982-3. [PMID: 11456636 DOI: 10.1021/ja0026408] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- K A Miller
- The University of Michigan Ann Arbor, Michigan 48109-1055, USA
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46
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Jackson P, Sändig N, Diefenbach M, Schröder D, Schwarz H, Srinivas R. The importance of dihydrogen complexes HnGe(H2)+ (n=0,1) to the chemistry of cationic germanium hydrides: advanced theoretical and mass spectrometric analysis. Chemistry 2001; 7:151-60. [PMID: 11205006 DOI: 10.1002/1521-3765(20010105)7:1<151::aid-chem151>3.0.co;2-d] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Investigations of [Ge,Hn]-/0/- (n = 2,3) have been performed using a four-sector mass spectrometer. The results reveal that the complexes HnGe(H2)+ (n = 0,1) play an important role in the unimolecular dissociation of the metastable cations. Theoretical calculations support the experimental observations in most instances, and the established view that the global minimum of [Ge,H2]+ is an inserted structure may need reexamination; CCSD(T,full)/cc-pVTZ//CCSD(T)/6-311 ++ G(d,p) and B3LYP/cc-pVTZ studies of three low-lying cation states (2A1 HGeH+, 2B2 Ge(H2)+ and 2B1 Ge(H2)+) indicate a very small energy difference (ca. 4 kcal mol(-1)) between 2A1 HGeH+ and 2B2 Ge(H2)+; B3LYP favours the ion-molecule complex, whereas coupled-cluster calculations favour the inserted structure for the global minimum. Single-point multireference (MR) averaged coupled-pair functional and MR-configuration interaction calculations give conflicting results regarding the global minimum. We also present theoretical evidence indicating that the orbital-crossing point implicated in the spin-allowed metastable dissociation HGeH+* --> Ge(H2)+* --> Ge+ + H2 lies above the H-loss asymptote. Thus, a quantum-mechanical tunneling mechanism is invoked to explain the preponderance of the H2-loss signal for the metastable ion.
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Affiliation(s)
- P Jackson
- Mass Spectrometry Unit, Research School of Chemistry, Australian National University, Canberra ACT.
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47
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Smith TC, Clouthier DJ, Sha W, Adam AG. Laser optogalvanic and jet spectroscopy of germylene (GeH2): New spectroscopic data for an important semiconductor growth intermediate. J Chem Phys 2000. [DOI: 10.1063/1.1319936] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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48
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Becerra R, Boganov SE, Egorov MP, Faustov VI, Nefedov OM, Walsh R. The insertion of germylene into the HH bond; rate constant limits and thermochemistry. Ab initio and DFT calculations on the reactions of GeH2 and SiH2 with H2. CAN J CHEM 2000. [DOI: 10.1139/v00-106] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The technique of laser flash photolysis in the gas-phase has been used to set limits on the rate constants for the bimolecular reaction of germylene (GeH2) with deuterium (D2) at both ambient and elevated temperatures (585 K). These limits show that the activation energy for the insertion of GeH2 into the HH bond is at least 19 (±6) kJ mol1. Thermochemical arguments place the activation energy approximately in the range 6384 kJ mol1. DFT B3LYP/6-311++G(3df,2pd) and ab initio QCISD(T)/6-311G++(3df,2pd)//QCISD/6-311G(d,p) calculations have been carried out on the potential energy surfaces of reactions ZH2 + H2 [Formula: see text] ZH4 (Z= Ge, Si). Both methods predict the same mechanisms for germylene and silylene insertion which include formation of loose prereaction complexes and transition states of similar structure. The prereaction complex is only about half as strong in the case of germylene (ΔH (298 K) = 9 (11) kJ mol1) as in the case of silylene (ΔH (298 K) = 16 (21) kJ mol1) (QCISD values cited with B3LYP values in parentheses). The differences in activation energies are even more significant. Germylene insertion has a very high barrier of 58 (56) kJ mol1 compared to that of silylene 13 (6) kJ mol1. Calculated activation parameters for both reactions are in reasonable consistency with experimental results. Reasons for the enhanced HH insertion barrier for germylene compared with silylene are discussed.Key words: laser flash photolysis, germylene, silylene, deuterium, activation energy, thermochemistry, ab initio calculation, DFT B3LYP calculation.
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Alexander UN, King KD, Lawrance WD. Temperature dependence of germylene reactions with acetylene, trimethylsilane, and phenylgermane. Chem Phys Lett 2000. [DOI: 10.1016/s0009-2614(00)00189-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Su MD, Chu SY. Density Functional and MP2 Studies of Germylene Insertion into C−H, Si−H, N−H, P−H, O−H, S−H, F−H, and Cl−H Bonds. J Phys Chem A 1999. [DOI: 10.1021/jp9916440] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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