1
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Esteruelas MA, López AM, Oliván M. Polyhydrides of Platinum Group Metals: Nonclassical Interactions and σ-Bond Activation Reactions. Chem Rev 2016; 116:8770-847. [DOI: 10.1021/acs.chemrev.6b00080] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Miguel A. Esteruelas
- 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
| | - Ana M. López
- 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
| | - Montserrat Oliván
- 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
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2
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Ram RS, Li G, Bernath PF. Fourier transform emission spectroscopy of YH and YD: observation of new A1Δ and B1Π electronic states. J Chem Phys 2011; 135:194308. [PMID: 22112083 DOI: 10.1063/1.3659295] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The emission spectra of YH and YD molecules have been investigated in the 3600-12,000 cm(-1) region using a Fourier transform spectrometer. Molecules were formed in an yttrium hollow cathode lamp operated with a continuous flow of a mixture of Ne and Ar gases, and YH and YD were observed together in the same spectra. A group of bands observed near 1 μm have been identified as 0-0 and 1-1 bands of the A(1)Δ-X(1)Σ(+) and B(1)Π-X(1)Σ(+) transitions of YH and the 0-0 bands of the same two transitions for YD. The A(1)Δ and B(1)Π states of YH are separated by only about 12 cm(-1) and are involved in strong interactions. A perturbation analysis has been performed using the PGOPHER program to fit the two interacting electronic states and spectroscopic parameters for the A(1)Δ and B(1)Π states, including the interaction matrix elements, have been obtained for the first time.
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Affiliation(s)
- R S Ram
- Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom.
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3
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Jones RC, Chojnacka MW, Quail JW, Gardiner MG, Decken A, Yates BF, Gossage RA. Oxazoles revisited: On the nature of binding of benzoxazole and 2-methylbenzoxazole with the zinc and palladium halides. Dalton Trans 2011; 40:1594-600. [DOI: 10.1039/c0dt01266a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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4
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Jensen KP. Metal−Ligand Bonds of Second- and Third-Row d-Block Metals Characterized by Density Functional Theory. J Phys Chem A 2009; 113:10133-41. [DOI: 10.1021/jp9061225] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kasper P. Jensen
- Department of Chemistry, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
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5
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Field LD, Magill AM, Dalgarno SJ, Jensen P. Bis(acetylido) Complexes of Ruthenium(II) Bearing Monodentate Phosphane Ligands. Eur J Inorg Chem 2008. [DOI: 10.1002/ejic.200800495] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Leslie D. Field
- School of Chemistry, University of New South Wales, High St., Kensington 2052, Australia, Fax: +61‐2‐9385‐8008
| | - Alison M. Magill
- School of Chemistry, University of New South Wales, High St., Kensington 2052, Australia, Fax: +61‐2‐9385‐8008
| | - Scott J. Dalgarno
- School of Engineering and Physical Sciences – Chemistry, Heriot–Watt University, Riccarton, Edinburgh EH14 4AS, UK
- Department of Chemistry, University of Missouri – Columbia, Columbia, Missouri 65211, USA
| | - Paul Jensen
- School of Chemistry, University of Sydney, Sydney 2006, Australia
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6
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Gossage RA, Jenkins HA, Jones ND, Jones RC, Yates BF. Pre-catalyst resting states: a kinetic, thermodynamic and quantum mechanical analyses of [PdCl2(2-oxazoline)2] complexes. Dalton Trans 2008:3115-22. [PMID: 18521454 DOI: 10.1039/b801951g] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The treatment of cold ( approximately 3 degrees C) methanolic solutions of Li(2)PdCl(4) with two equivalents of 2-phenyl-2-oxazoline (Phox) results in the isolation of [PdCl(2)(Phox)(2)] (3). This complex undergoes remarkably slow isomerisation (CHCl(3)-d) at room temperature to a corresponding thermodynamic form. In addition to a theoretical treatment (DFT), the isomerisation behaviour has been analysed both kinetically and thermodynamically. These investigations lead to the conclusion that the initially formed (i.e. kinetic) isomer of 3 is the cis-form which undergoes conversion to the corresponding thermodynamic trans-form via a dissociative (D) mechanism involving loss of a Phox ligand. The activation parameters DeltaS(double dagger) and DeltaH(double dagger) are found to be +304 (+/-3) J K(-1) mol(-1) and +176 (+/-1) kJ mol(-1), respectively and indicate a high barrier to Pd-N bond cleavage under these conditions. The thermodynamic parameters show the expected endothermic nature of this process (+140 +/- 17 kJ mol(-1)) and a slight positive overall entropy (DeltaS degrees = +17 +/- 2 J K(-1) mol(-1)); this latter parameter is presumably due to the formation of the lower dipole moment trans-product when compared to the cis-isomer. Calculated (DFT) values of DeltaG(double dagger) and DeltaH(double dagger) are in excellent agreement to those found experimentally. Further theoretical investigation suggests that two 14-electron three-coordinate T-shaped transition states (i.e., [PdCl(2)(Phox)](double dagger)) are involved; the form pre-disposed to yield the thermodynamic trans-product following re-attachment of the released oxazoline is found to be energetically favoured. The analogous alkyloxazoline system [PdCl(2)(Meox)(2)] (4: Meox = 2-methyl-2-oxazoline) has likewise been investigated. This material gives no indication of cis-trans isomerisation behaviour in solution (NMR) and is shown to exist (X-ray) in the trans-form in the solid-state (as do previously reported crystalline samples of 3). A DFT study of 4 reveals similar values of DeltaS(double dagger) and DeltaH(double dagger) if a D type mechanism were operating to rapidly convert cis- to trans-4. However, a significantly higher thermodynamic stability of the trans-isomer relative to the cis-form is revealed versus similar calculations of the Phox derivative 3. This suggests the possibility that (i) reactions of Meox with Li(2)PdCl(4) may lead directly to the trans-form of [PdCl(2)(Meox)(2)] or alternatively (ii) that alkyloxazoline complexes such as 4 may have a different, and presumably much more rapid, mechanism for isomerisation. The results are placed into the context that isomerisation behaviour, or lack thereof, could play a key preliminary role in later substrate modification. This is due to the fact that [PdX(2)(oxazoline)(2)] compounds are well-known (pre-)catalysts for C-C bond forming chemistry.
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Affiliation(s)
- Robert A Gossage
- The David Upton Hill Laboratories of Inorganic Chemistry, Department of Chemistry, Acadia University, Wolfville, NS B4P 2R6, Canada.
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7
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Tsai HHG, Chung MW, Chou YK, Hou DR. Interplay of Hydrogenation and Dehydrogenation in Isoindoline and Indoline Isomers: A Density Functional Theory Study. J Phys Chem A 2008; 112:5278-85. [DOI: 10.1021/jp7121246] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hui-Hsu Gavin Tsai
- Department of Chemistry, National Central University, Jhong-Li City Tao-Yuan County 32001, Taiwan
| | - Ming-Weng Chung
- Department of Chemistry, National Central University, Jhong-Li City Tao-Yuan County 32001, Taiwan
| | - Yi-Kang Chou
- Department of Chemistry, National Central University, Jhong-Li City Tao-Yuan County 32001, Taiwan
| | - Duen-Ren Hou
- Department of Chemistry, National Central University, Jhong-Li City Tao-Yuan County 32001, Taiwan
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8
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Armentrout PB. Activation of C2H6 and C3H8 by Gas-Phase Mo+: Potential Energy Surfaces and Reaction Mechanisms. Organometallics 2007. [DOI: 10.1021/om700578q] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- P. B. Armentrout
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112
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9
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Armentrout PB. Activation of C2H6 and C3H8 by Gas-Phase Mo+: Thermochemistry of Mo−Ligand Complexes. Organometallics 2007. [DOI: 10.1021/om700579m] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- P. B. Armentrout
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112
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10
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Schultz NE, Zhao Y, Truhlar DG. Databases for transition element bonding: metal-metal bond energies and bond lengths and their use to test hybrid, hybrid meta, and meta density functionals and generalized gradient approximations. J Phys Chem A 2007; 109:4388-403. [PMID: 16833770 DOI: 10.1021/jp0504468] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We propose a data set of bond lengths for 8 selected transition metal dimers (Ag(2), Cr(2), Cu(2), CuAg, Mo(2), Ni(2), V(2), and Zr(2)) and another data set containing their atomization energies and the atomization energy of ZrV, and we use these for testing density functional theory. The molecules chosen for the test sets were selected on the basis of the expected reliability of the data and their ability to constitute a diverse and representative set of transition element bond types while the data sets are kept small enough to allow for efficient testing of a large number of computational methods against a very reliable subset of experimental data. In this paper we test 42 different functionals: 2 local spin density approximation (LSDA) functionals, 12 generalized gradient approximation (GGA) methods, 13 hybrid GGAs, 7 meta GGA methods, and 8 hybrid meta GGAs. We find that GGA density functionals are more accurate for the atomization energies of pure transition metal systems than are their meta, hybrid, or hybrid meta analogues. We find that the errors for atomization energies and bond lengths are not as large if we limit ourselves to dimers with small amounts of multireference character. We also demonstrate the effects of increasing the fraction of Hartree-Fock exchange in multireference systems by computing the potential energy curve for Cr(2) and Mo(2) with several functionals. We also find that BLYP is the most accurate functional for bond energies and is reasonably accurate for bond lengths. The methods that work well for transition metal bonds are found to be quite different from those that work well for organic and other main group chemistry.
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Affiliation(s)
- Nathan E Schultz
- Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant Street Southeast, Minneapolis, MN 55455-0431, USA
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11
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Intramolecular rearrangements of β-diketonates of metals. A non-emprical study of the structure of Y(MDA)3 and La(MDA)3 complexes. J STRUCT CHEM+ 2007. [DOI: 10.1007/s10947-007-0063-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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12
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Pillai ED, Jaeger TD, Duncan MA. IR Spectroscopy of Nb+(N2)n Complexes: Coordination, Structures, and Spin States. J Am Chem Soc 2007; 129:2297-307. [PMID: 17279746 DOI: 10.1021/ja0661008] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Infrared photodissociation spectroscopy in the N-N stretching region is reported for gas-phase Nb+(N2)n complexes (n=3-16). The coordination of nitrogen to the metal cation causes the IR-forbidden N-N stretch of N2 to become active in these complexes. Fragmentation occurs by the loss of intact N2 molecules, and the yield as a function of laser wavelength produces an IR excitation spectrum. The dissociation patterns indicate that Nb+ has a coordination of six ligands. The infrared spectra for all complexes contain bands red-shifted from the N-N stretch in free nitrogen, consistent with ligand-metal charge-transfer interactions such as those familiar for metal carbonyl complexes. Using density functional theory, we investigated the structures and ground electronic states for each of the small cluster sizes. Theory indicates that binding to the low-spin triplet excited state of the metal ion becomes progressively more favorable than binding to its high-spin quintet ground state as additional ligands are added to the cluster. Although the quintet state is the ground state for the n=1-4 complexes, IR spectroscopy confirms that the low-spin triplet electronic state becomes the ground state for the n=5 and 6 complexes. The n=4 complex has a square-planar structure, familiar for high-spin d4 complexes in the condensed phase. The n=5 complex has a geometry that is nearly a square pyramid, while the n=6 complex has a structure close to octahedral.
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Affiliation(s)
- E Dinesh Pillai
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
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13
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Cundari TR, Benson MT, Lutz ML, Sommerer SO. Effective Core Potential Approaches to the Chemistry of the Heavier Elements. REVIEWS IN COMPUTATIONAL CHEMISTRY 2007. [DOI: 10.1002/9780470125854.ch3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
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14
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Lee CC, Ke WC, Chan KT, Lai CL, Hu CH, Lee HM. Nickel(II) Complexes of Bidentate N-Heterocyclic Carbene/Phosphine Ligands: Efficient Catalysts for Suzuki Coupling of Aryl Chlorides. Chemistry 2007; 13:582-91. [PMID: 16969780 DOI: 10.1002/chem.200600502] [Citation(s) in RCA: 160] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Nickel(II) complexes of bidentate N-heterocyclic carbene (NHC)/phosphane ligand L were prepared and structurally characterized. Unlike palladium, which forms [PdCl(2)(L)], the stable nickel product isolated is the ionic [Ni(L)(2)]Cl(2). These Ni(II) complexes are highly robust in air. Among different N-substituents on the ligand framework, the nickel complex of ligand L bearing N-1-naphthylmethyl groups (2 a) is a highly effective catalyst for Suzuki cross-coupling between phenylboronic acid and a range of aryl halides, including unreactive aryl chlorides. The activities of 2 a are largely superior to those of other reported nickel NHC complexes and their palladium counterparts. Unlike the previously reported [NiCl(2)(dppe)] (dppe=1,2-bis(diphenylphosphino)ethane), 2 a can effectively catalyze the cross-coupling reaction without the need for a catalytic amount of PPh(3), and this suggests that the PPh(2) functionality of hybrid NHC ligand L can partially take on the role of free PPh(3). However, for unreactive aryl chlorides at low catalyst loading, the presence of PPh(3) accelerates the reaction.
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Affiliation(s)
- Chun-Chin Lee
- Department of Chemistry, National Changhua University of Education, Changhua, Taiwan
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15
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Graham DC, Cavell KJ, Yates BF. Oxidative addition of 2-substituted azolium salts to Group-10 metal zero complexes—A DFT study. Dalton Trans 2007:4650-8. [DOI: 10.1039/b709914b] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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Cooper DL, Gerratt J, Raimondi M. The Spin-coupled Approach to Electronic Structure. MOLECULAR SIMULATION 2006. [DOI: 10.1080/08927029008022393] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- David L. Cooper
- a Department of Chemistry , University of Liverpool , P.O. Box 147, Liverpool , L69 3BX , UK
| | - Joseph Gerratt
- b Department of Theoretical Chemistry , University of Bristol , Cantocks Close, Bristol , BS8 1TS , UK
| | - Mario Raimondi
- c Dipartimento di Chimica Fisica ed Elettrochimica , Università di Milano , Via Golgi 19, 20133 , Milano , Italy
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17
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Koseki S, Matsushita T, Gordon MS. Dissociation Potential Curves of Low-Lying States in Transition Metal Hydrides. 3. Hydrides of Groups 6 and 7. J Phys Chem A 2006; 110:2560-70. [PMID: 16480317 DOI: 10.1021/jp056258z] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The dissociation curves of low-lying spin-mixed states in monohydrides of groups 6 and 7 were calculated by using an effective core potential (ECP) approach. This approach is based on the multiconfiguration self-consistent field (MCSCF) method, followed by first-order configuration interaction (FOCI) calculations, in which the method employs an ECP basis set proposed by Stevens and co-workers (SBKJC) augmented by a set of polarization functions. Spin-orbit coupling (SOC) effects are estimated within the one-electron approximation by using effective nuclear charges, since SOC splittings obtained with the full Breit-Pauli Hamitonian are underestimated when ECP basis sets are used. The ground states of group 6 hydrides have Omega = (1)/(2)(X(6)Sigma(+)(1/2)), where Omega is the z component of the total angular momentum quantum number. Although the ground states of group 7 hydrides have Omega = 0(+), their main adiabatic components are different; the ground state in MnH originates from the lowest (7)Sigma(+), while in TcH and ReH the main component of the ground state is the lowest (5)Sigma(+). The present paper reports a comprehensive set of theoretical results including the dissociation energies, equilibrium distances, electronic transition energies, harmonic frequencies, anharmonicities, and rotational constants for several low-lying spin-mixed states in these hydrides. Transition dipole moments were also computed among the spin-mixed states and large peak positions of electronic transitions are suggested theoretically for these hydrides. The periodic trends of physical properties of metal hydrides are discussed, based on the results reported in this and other recent studies.
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Affiliation(s)
- Shiro Koseki
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531, Japan.
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18
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de Jong GT, Bickelhaupt FM. Oxidative Addition of the Chloromethane C−Cl Bond to Pd, an ab Initio Benchmark and DFT Validation Study. J Chem Theory Comput 2006; 2:322-35. [DOI: 10.1021/ct050254g] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- G. Theodoor de Jong
- Afdeling Theoretische Chemie, Scheikundig Laboratorium der Vrije Universiteit, De Boelelaan 1083, NL-1081 HV Amsterdam, The Netherlands
| | - F. Matthias Bickelhaupt
- Afdeling Theoretische Chemie, Scheikundig Laboratorium der Vrije Universiteit, De Boelelaan 1083, NL-1081 HV Amsterdam, The Netherlands
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19
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Graham DC, Cavell KJ, Yates BF. The influence of N-substitution on the reductive elimination behaviour of hydrocarbyl–palladium–carbene complexes—a DFT study. Dalton Trans 2006:1768-75. [PMID: 16568186 DOI: 10.1039/b512681a] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reductive elimination of 2-hydrocarbyl-imidazolium salts from hydrocarbyl-palladium complexes bearing N-heterocyclic carbene (NHC) ligands represents an important deactivation route for catalysts of this type. We have explored the influence that carbene N-substituents have on both the activation energy and the overall thermodynamics of the reductive elimination reaction using density functional theory (DFT). Given the proximity of the N-substituent to the three-centred transition structure, steric bulk has little influence on the activation barrier and it is electronic factors that dominate the barriers' magnitude. Increased electron donation from the departing NHC ligand acts to stabilise the associated complex against reductive elimination, with stability following the trend: Cl < H < Ph < Me < Cy < iPr < neopentyl < tBu. The intimate involvement of the carbene p pi-orbital in determining the barrier to reductive elimination means N-substituents that are capable of removing pi-density (e.g. phenyl) act to promote a more facile reductive elimination.
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Affiliation(s)
- David C Graham
- School of Chemistry, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001, Australia
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20
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Chiu PL, Lai CL, Chang CF, Hu CH, Lee HM. Synthesis, Structural Characterization, Computational Study, and Catalytic Activity of Metal Complexes Based on Tetradentate Pyridine/N-Heterocyclic Carbene Ligand. Organometallics 2005. [DOI: 10.1021/om050224w] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Pei Ling Chiu
- Department of Chemistry, National Changhua University of Education, Changhua, Taiwan 50058, Republic of China
| | - Chun-Liang Lai
- Department of Chemistry, National Changhua University of Education, Changhua, Taiwan 50058, Republic of China
| | - Chiung-Fang Chang
- Department of Chemistry, National Changhua University of Education, Changhua, Taiwan 50058, Republic of China
| | - Ching-Han Hu
- Department of Chemistry, National Changhua University of Education, Changhua, Taiwan 50058, Republic of China
| | - Hon Man Lee
- Department of Chemistry, National Changhua University of Education, Changhua, Taiwan 50058, Republic of China
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21
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de Jong GT, Bickelhaupt FM. Oxidative Addition of the Fluoromethane C−F Bond to Pd. An ab Initio Benchmark and DFT Validation Study. J Phys Chem A 2005; 109:9685-99. [PMID: 16866421 DOI: 10.1021/jp053587i] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have computed a state-of-the-art benchmark potential energy surface (PES) for two reaction pathways (oxidative insertion, OxIn, and S(N)2) for oxidative addition of the fluoromethane C-F bond to the palladium atom and have used this to evaluate the performance of 26 popular density functionals, covering LDA, GGA, meta-GGA, and hybrid density functionals, for describing these reactions. The ab initio benchmark is obtained by exploring the PES using a hierarchical series of ab initio methods (HF, MP2, CCSD, CCSD(T)) in combination with a hierarchical series of seven Gaussian-type basis sets, up to g polarization. Relativistic effects are taken into account through a full four-component all-electron approach. Our best estimate of kinetic and thermodynamic parameters is -5.3 (-6.1) kcal/mol for the formation of the reactant complex, 27.8 (25.4) kcal/mol for the activation energy for oxidative insertion (OxIn) relative to the separate reactants, 37.5 (31.8) kcal/mol for the activation energy for the alternative S(N)2 pathway, and -6.4 (-7.8) kcal/mol for the reaction energy (zero-point vibrational energy-corrected values in parentheses). Our work highlights the importance of sufficient higher angular momentum polarization functions for correctly describing metal-d-electron correlation. Best overall agreement with our ab initio benchmark is obtained by functionals from all three categories, GGA, meta-GGA, and hybrid DFT, with mean absolute errors of 1.4-2.7 kcal/mol and errors in activation energies ranging from 0.3 to 2.8 kcal/mol. The B3LYP functional compares very well with a slight underestimation of the overall barrier for OxIn by -0.9 kcal/mol. For comparison, the well-known BLYP functional underestimates the overall barrier by -10.1 kcal/mol. The relative performance of these two functionals is inverted with respect to previous findings for the insertion of Pd into the C-H and C-C bonds. However, all major functionals yield correct trends and qualitative features of the PES, in particular, a clear preference for the OxIn over the alternative S(N)2 pathway.
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Affiliation(s)
- G Theodoor de Jong
- Afdeling Theoretische Chemie, Scheikundig Laboratorium der Vrije Universiteit, De Boelelaan 1083, NL-1081 HV Amsterdam, The Netherlands
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22
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Wang X, Andrews L. Matrix Infrared Spectra and Density Functional Theory Calculations of Molybdenum Hydrides. J Phys Chem A 2005; 109:9021-7. [PMID: 16332007 DOI: 10.1021/jp053591u] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Laser-ablated Mo atoms react with H2 upon condensation in excess argon, neon, and hydrogen. The molybdenum hydrides MoH, MoH2, MoH4, and MoH6 are identified by isotopic substitution (H2, D2, HD, H2 + D2) and by comparison with vibrational frequencies calculated by density functional theory. The MoH2 molecule is bent, MoH4 is tetrahedral, and MoH6 appears to have the distorted trigonal prism structure.
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Affiliation(s)
- Xuefeng Wang
- Department of Chemistry, University of Virginia, McCormick Road, P.O. Box 400319, Charlottesville, Virginia 22904-4319, USA
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23
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De Jong GT, Geerke DP, Diefenbach A, Solà M, Bickelhaupt FM. Oxidative addition of the ethane CC bond to Pd. Anab initiobenchmark and DFT validation study. J Comput Chem 2005; 26:1006-20. [PMID: 15880815 DOI: 10.1002/jcc.20233] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We have computed a state-of-the-art benchmark potential energy surface (PES) for the archetypal oxidative addition of the ethane C-C bond to the palladium atom and have used this to evaluate the performance of 24 popular density functionals, covering LDA, GGA, meta-GGA, and hybrid density functionals, for describing this reaction. The ab initio benchmark is obtained by exploring the PES using a hierarchical series of ab initio methods [HF, MP2, CCSD, CCSD(T)] in combination with a hierarchical series of five Gaussian-type basis sets, up to g polarization. Relativistic effects are taken into account either through a relativistic effective core potential for palladium or through a full four-component all-electron approach. Our best estimate of kinetic and thermodynamic parameters is -10.8 (-11.3) kcal/mol for the formation of the reactant complex, 19.4 (17.1) kcal/mol for the activation energy relative to the separate reactants, and -4.5 (-6.8) kcal/mol for the reaction energy (zero-point vibrational energy-corrected values in parentheses). Our work highlights the importance of sufficient higher angular momentum polarization functions for correctly describing metal-d-electron correlation. Best overall agreement with our ab initio benchmark is obtained by functionals from all three categories, GGA, meta-GGA, and hybrid DFT, with mean absolute errors of 1.5 to 2.5 kcal/mol and errors in activation energies ranging from -0.2 to -3.2 kcal/mol. Interestingly, the well-known BLYP functional compares very reasonably with a slight underestimation of the overall barrier by -0.9 kcal/mol. For comparison, with B3LYP we arrive at an overestimation of the overall barrier by 5.8 kcal/mol. On the other hand, B3LYP performs excellently for the central barrier (i.e., relative to the reactant complex) which it underestimates by only -0.1 kcal/mol.
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Affiliation(s)
- G Theodoor De Jong
- Afdeling Theoretische Chemie, Scheikundig Laboratorium der Vrije Universiteit, De Boelelaan 1083, NL-1081 HV Amsterdam, The Netherlands
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24
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Jones RC, Madden RL, Skelton BW, Tolhurst VA, White AH, Williams AM, Wilson AJ, Yates BF. Solution, Structural and Catalytic Studies of Neutral MCl2 (M = Pd, Pt) Complexes of the N/E Mixed-Donor Ligands 2-(RECH2)C5H4N(RE = MeS, PhS, MeSe). Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200400514] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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25
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Graham DC, Cavell KJ, Yates BF. Influence of geometry on reductive elimination of hydrocarbyl–palladium–carbene complexes. Dalton Trans 2005:1093-100. [PMID: 15739012 DOI: 10.1039/b417111j] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The influence of spectator ligand bite angle and the twist angle of the carbene on the reductive elimination of N-heterocyclic carbenes (NHCs) from palladium bis-phosphine complexes has been investigated using density functional theory. The spectator bite angle was found to have a significant influence on both the activation energy (E(act)) and the enthalpy of reaction. Widening of the bite angle was found to lower E(act) and increase the enthalpy of reaction. In contrast, rotation of the carbene with respect to the PdL(2) plane was found to have little influence on E(act). At carbene twist angles approaching 0 degrees however, relief of the increased steric strain provides a considerable driving force for the decomposition reaction.
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Affiliation(s)
- David C Graham
- School of Chemistry, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001, Australia
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26
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de Jong GT, Solà M, Visscher L, Bickelhaupt FM. Ab initio benchmark study for the oxidative addition of CH4 to Pd: Importance of basis-set flexibility and polarization. J Chem Phys 2004; 121:9982-92. [PMID: 15549873 DOI: 10.1063/1.1792151] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
To obtain a state-of-the-art benchmark potential energy surface (PES) for the archetypal oxidative addition of the methane C-H bond to the palladium atom, we have explored this PES using a hierarchical series of ab initio methods (Hartree-Fock, second-order Møller-Plesset perturbation theory, fourth-order Møller-Plesset perturbation theory with single, double and quadruple excitations, coupled cluster theory with single and double excitations (CCSD), and with triple excitations treated perturbatively [CCSD(T)]) and hybrid density functional theory using the B3LYP functional, in combination with a hierarchical series of ten Gaussian-type basis sets, up to g polarization. Relativistic effects are taken into account either through a relativistic effective core potential for palladium or through a full four-component all-electron approach. Counterpoise corrected relative energies of stationary points are converged to within 0.1-0.2 kcal/mol as a function of the basis-set size. Our best estimate of kinetic and thermodynamic parameters is -8.1 (-8.3) kcal/mol for the formation of the reactant complex, 5.8 (3.1) kcal/mol for the activation energy relative to the separate reactants, and 0.8 (-1.2) kcal/mol for the reaction energy (zero-point vibrational energy-corrected values in parentheses). This agrees well with available experimental data. Our work highlights the importance of sufficient higher angular momentum polarization functions, f and g, for correctly describing metal-d-electron correlation and, thus, for obtaining reliable relative energies. We show that standard basis sets, such as LANL2DZ+1f for palladium, are not sufficiently polarized for this purpose and lead to erroneous CCSD(T) results. B3LYP is associated with smaller basis set superposition errors and shows faster convergence with basis-set size but yields relative energies (in particular, a reaction barrier) that are ca. 3.5 kcal/mol higher than the corresponding CCSD(T) values.
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Affiliation(s)
- G Theodoor de Jong
- Afdeling Theoretische Chemie, Scheikundig Laboratorium der Vrije Universiteit, De Boelelaan 1083, NL-1081 HV Amsterdam, The Netherlands
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27
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Schwarz J, Heinemann C, Schröder D, Schwarz H, Hrušák J. Unparalleled, Enormous Metal-Carbon Bond Strength in PdCH2I+. Helv Chim Acta 2004. [DOI: 10.1002/hlca.19960790102] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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28
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Schwarz J, Schröder D, Schwarz H, Heinemann C, Hrušák J. Theory-enforced Re-investigation of the Origin of the Large Metal-Carbon Bond Strength in PdCH2I+and its reactions with unsaturated hydrocarbons. Helv Chim Acta 2004. [DOI: 10.1002/hlca.19960790419] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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29
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Koseki S, Ishihara Y, Fedorov DG, Umeda H, Schmidt MW, Gordon MS. Dissociation Potential Curves of Low-Lying States in Transition Metal Hydrides. 2. Hydrides of Groups 3 and 5. J Phys Chem A 2004. [DOI: 10.1021/jp049839h] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shiro Koseki
- Department of Material Science, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531, Japan, National Institute of Advanced Industrial Science and Technology and Grid Technology Research Center, 1-1-1 Umezono, Tsukuba, Ibaraki 305-6568, Japan, and Department of Chemistry, Iowa State University, Ames, Iowa 50011
| | - Yohei Ishihara
- Department of Material Science, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531, Japan, National Institute of Advanced Industrial Science and Technology and Grid Technology Research Center, 1-1-1 Umezono, Tsukuba, Ibaraki 305-6568, Japan, and Department of Chemistry, Iowa State University, Ames, Iowa 50011
| | - Dmitri G. Fedorov
- Department of Material Science, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531, Japan, National Institute of Advanced Industrial Science and Technology and Grid Technology Research Center, 1-1-1 Umezono, Tsukuba, Ibaraki 305-6568, Japan, and Department of Chemistry, Iowa State University, Ames, Iowa 50011
| | - Hiroaki Umeda
- Department of Material Science, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531, Japan, National Institute of Advanced Industrial Science and Technology and Grid Technology Research Center, 1-1-1 Umezono, Tsukuba, Ibaraki 305-6568, Japan, and Department of Chemistry, Iowa State University, Ames, Iowa 50011
| | - Michael W. Schmidt
- Department of Material Science, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531, Japan, National Institute of Advanced Industrial Science and Technology and Grid Technology Research Center, 1-1-1 Umezono, Tsukuba, Ibaraki 305-6568, Japan, and Department of Chemistry, Iowa State University, Ames, Iowa 50011
| | - Mark S. Gordon
- Department of Material Science, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531, Japan, National Institute of Advanced Industrial Science and Technology and Grid Technology Research Center, 1-1-1 Umezono, Tsukuba, Ibaraki 305-6568, Japan, and Department of Chemistry, Iowa State University, Ames, Iowa 50011
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30
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McGuinness DS, Yates BF, Cavell KJ. Theoretical Study of Methyl-PdII N-Heterocyclic Silylene and Germylene Complexes: Comparisons to N-Heterocyclic Carbene Reactivity. Organometallics 2002. [DOI: 10.1021/om020750c] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- David S. McGuinness
- Institut für Technische Chemie und Makromolekulare Chemie der RWTH Aachen, Worringer Weg 1, 52074 Aachen, Germany, School of Chemistry, University of Tasmania, GPO Box 252-75, Hobart 7001, Tasmania, Australia, and Department of Chemistry, Cardiff University, PO Box 912, Cardiff, CF1 3TB, U.K
| | - Brian F. Yates
- Institut für Technische Chemie und Makromolekulare Chemie der RWTH Aachen, Worringer Weg 1, 52074 Aachen, Germany, School of Chemistry, University of Tasmania, GPO Box 252-75, Hobart 7001, Tasmania, Australia, and Department of Chemistry, Cardiff University, PO Box 912, Cardiff, CF1 3TB, U.K
| | - Kingsley J. Cavell
- Institut für Technische Chemie und Makromolekulare Chemie der RWTH Aachen, Worringer Weg 1, 52074 Aachen, Germany, School of Chemistry, University of Tasmania, GPO Box 252-75, Hobart 7001, Tasmania, Australia, and Department of Chemistry, Cardiff University, PO Box 912, Cardiff, CF1 3TB, U.K
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31
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Wang X, Chertihin GV, Andrews L. Matrix Infrared Spectra and DFT Calculations of the Reactive MHx (x = 1, 2, and 3), (H2)MH2, MH2+, and MH4- (M = Sc, Y, and La) Species. J Phys Chem A 2002. [DOI: 10.1021/jp026166z] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Xuefeng Wang
- Department of Chemistry, P.O. Box 400319, University of Virginia, Charlottesville, Virginia 22904-4319
| | - George V. Chertihin
- 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
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32
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Wang X, Andrews L. Infrared Spectra of Rhodium Hydrides in Solid Argon, Neon, and Deuterium with Supporting Density Functional Calculations. J Phys Chem A 2002. [DOI: 10.1021/jp013624f] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Xuefeng Wang
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319
| | - Lester Andrews
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319
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33
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Koseki S, Ishihara Y, Umeda H, Fedorov DG, Gordon MS. Dissociation Potential Curves of Low-Lying States in Transition Metal Hydrides. I. Hydrides of Group 4. J Phys Chem A 2002. [DOI: 10.1021/jp012644e] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Shiro Koseki
- Chemistry Department for Materials, Faculty of Engineering, Mie University, Tsu 514-8507, Japan, and Department of Chemistry, Iowa State University, Ames, Iowa 50011
| | - Yohei Ishihara
- Chemistry Department for Materials, Faculty of Engineering, Mie University, Tsu 514-8507, Japan, and Department of Chemistry, Iowa State University, Ames, Iowa 50011
| | - Hiroaki Umeda
- Chemistry Department for Materials, Faculty of Engineering, Mie University, Tsu 514-8507, Japan, and Department of Chemistry, Iowa State University, Ames, Iowa 50011
| | - Dmitri G. Fedorov
- Chemistry Department for Materials, Faculty of Engineering, Mie University, Tsu 514-8507, Japan, and Department of Chemistry, Iowa State University, Ames, Iowa 50011
| | - Mark S. Gordon
- Chemistry Department for Materials, Faculty of Engineering, Mie University, Tsu 514-8507, Japan, and Department of Chemistry, Iowa State University, Ames, Iowa 50011
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34
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Jakubek ZJ, Simard B, Balfour WJ. Disentangling the mystery of green bands of yttrium monohydride with the help of Stark spectroscopy. Chem Phys Lett 2002. [DOI: 10.1016/s0009-2614(01)01398-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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35
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McGuinness DS, Cavell KJ, Yates BF, Skelton BW, White AH. Oxidative addition of the imidazolium cation to zerovalent Ni, Pd, and Pt: a combined density functional and experimental study. J Am Chem Soc 2001; 123:8317-28. [PMID: 11516281 DOI: 10.1021/ja010628p] [Citation(s) in RCA: 198] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Oxidative addition of different imidazolium cations to zerovalent group 10 metals, to afford heterocyclic carbene complexes, has been investigated by both density functional theory (DFT) and experimental studies. The theoretical analysis shows that addition of imidazoliums to Pt(0) and Ni(0) is more exothermic than to Pd(0), and Ni(0) is predicted to react with a much lower barrier than either Pt(0) or Pd(0). Strongly basic supporting ligands on the metal, as well as cis-chelating ligands, increase the exothermicity of the reaction and also lower the activation barrier. The addition of 2-H imidazoliums is easier and more exothermic than addition of 2-alkylimidazoliums, and a halo-imidazolium is expected to further lower the barrier to oxidative addition and increase the exothermicity. The DFT results show that all three of the metals should be able to oxidatively add imidazolium cations under appropriate conditions. Experimental studies confirmed that oxidative addition is possible, and a number of Pt- and Pd-carbene complexes were prepared via oxidative addition of imidazolium salts to M(0) precursors. Most significantly, oxidative addition of 2-H azolium salts was found to readily occur, and the reaction of 1,3-dimethylimidazolium tetrafluoroborate with Pt(PPh(3))(2) and Pt(PCy(3))(2) affords [PtH(dmiy)(PPh(3))(2)]BF(4) (10) and [PtH(dmiy)(PCy(3))(2)]BF(4) (11), while reaction between 3,4-dimethylthiazolium tetrafluoroborate and Pt(PCy(3))(2) yields [PtH(dmty)(PCy(3))(2)]BF(4) (12) (dmiy = 1,3-dimethylimidazolin-2-ylidene, dmty = 3,4-dimethylthiazolin-2-ylidene). Addition of 2-iodo-1,3,4,5-tetramethylimidazolium tetrafluoroborate to Pt(PPh(3))(4) or Pd(dcype)(dba) yields [PtI(tmiy)(PPh(3))(2)]BF(4) (9) and [PdI(tmiy)(dcype)]BF(4) (14), respectively (tmiy = 1,3,4,5-tetramethylimidazolin-2-ylidene, dcype = 1,3-bis(dicyclohexylphosphino)ethane)). X-ray crystal structures are reported for complexes 9 and 11 (cis and trans). These studies clearly show for the first time that oxidative addition of imidazolium and thiazolium cations is possible, and the results are discussed in terms of the ramifications for catalysis in imidazolium-based ionic liquids with both carbene-based and non-carbene-based complexes.
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Affiliation(s)
- D S McGuinness
- School of Chemistry, University of Tasmania, GPO Box 252-75 Hobart, Tasmania 7001, Australia
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36
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Dubois V, Archirel P, Boutin A. Monte Carlo Simulations of Ag+ and Ag in Aqueous Solution. Redox Potential of the Ag+/Ag Couple. J Phys Chem B 2001. [DOI: 10.1021/jp0045888] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Vincent Dubois
- Laboratoire de Chimie-Physique, UMR 8000, Bât. 350, Université Paris-Sud, 91405 Orsay Cédex, France
| | - Pierre Archirel
- Laboratoire de Chimie-Physique, UMR 8000, Bât. 350, Université Paris-Sud, 91405 Orsay Cédex, France
| | - Anne Boutin
- Laboratoire de Chimie-Physique, UMR 8000, Bât. 350, Université Paris-Sud, 91405 Orsay Cédex, France
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37
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McGuinness DS, Saendig N, Yates BF, Cavell KJ. Kinetic and density functional studies on alkyl-carbene elimination from Pd(II) heterocylic carbene complexes: a new type of reductive elimination with clear implications for catalysis. J Am Chem Soc 2001; 123:4029-40. [PMID: 11457154 DOI: 10.1021/ja003861g] [Citation(s) in RCA: 210] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A number of new methyl-Pd(II) complexes of heterocyclic carbenes of the form [PdMe(tmiy)L(2)]BF(4) have been prepared, and their reaction behavior has been studied (tmiy = 1,3,4,5-tetramethylimidazolin-2-ylidene, L = cyclooctadiene (8), methyldiphenylphosphine (9), triphenyl phosphite (10), triphenylphosphine (11)). In common with other hydrocarbyl-M carbene complexes (M = Pd, Ni) the complexes are predisposed to a facile decomposition process. A detailed mechanism for the process and of the decomposition pathway followed is presented herein. All complexes decompose with first-order kinetics to yield 1,2,3,4,5-pentamethylimidazolium tetrafluoroborate and Pd(0) species. The kinetic investigations combined with density functional studies show that the complexes decompose via a mechanism of concerted reductive elimination of the methyl group and carbene. The reaction represents a new type of reductive elimination from transition metals and also represents a low-energy pathway to catalyst deactivation for catalysts based on heterocyclic carbenes. The theoretical studies indicate extensive involvement of the p(pi) orbital on the carbene carbon in the transition structure. Methods of stabilizing catalysts based on heterocyclic carbene complexes are suggested, and the possibility of involvement of carbene species during catalysis in ionic liquids is discussed.
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Affiliation(s)
- D S McGuinness
- Contribution from the School of Chemistry, University of Tasmania, GPO Box 252-75 Hobart, Tasmania 7001, Australia
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38
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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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39
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10 Transition metal monohydrides. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s1075-1629(01)80012-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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40
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Witek HA, Nakijima T, Hirao K. Relativistic and correlated all-electron calculations on the ground and excited states of AgH and AuH. J Chem Phys 2000. [DOI: 10.1063/1.1308554] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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41
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42
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Balfour WJ, Cao J, Qian CX. Characterization of Electronic Spectra of Rhodium Monohydride and Monodeuteride. JOURNAL OF MOLECULAR SPECTROSCOPY 2000; 201:244-248. [PMID: 10814486 DOI: 10.1006/jmsp.2000.8082] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The electronic spectra of rhodium monohydride and monodeuteride, obtained using a molecular beam laser vaporization source, have been investigated from 400 to 500 nm, by laser excitation and dispersed fluorescence spectroscopies. The ground level of RhH is (3)Delta(3) with omega(e) approximately 2040 cm(-1) and omega(e)x(e) approximately 46 cm(-1). The corresponding RhD data are omega(e) approximately 1422 cm(-1) and omega(e)x(e) approximately 18 cm(-1). The estimated ground state bond length is r(0) = 0.159 nm. Excited states with Omega = 2, 3, and 4 have been observed. Copyright 2000 Academic Press.
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Affiliation(s)
- WJ Balfour
- Department of Chemistry, University of Victoria, Victoria, British Columbia, V8W 3P6, Canada
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43
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On the R2PI spectrum of AgNH3: a theoretical study of the quasidegeneracy of the first excited states. Chem Phys Lett 2000. [DOI: 10.1016/s0009-2614(00)00399-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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44
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Affiliation(s)
- A Dedieu
- Laboratoire de Chimie Quantique, UMR 7551 CNRS/ULP, Université Louis Pasteur, 4 rue Blaise Pascal, 67000 Strasbourg, France
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45
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Sakai Y, Mogi K, Miyoshi E. Theoretical study of low-lying electronic states of TiCl and ZrCl. J Chem Phys 1999. [DOI: 10.1063/1.479701] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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46
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van Wüllen C. Molecular density functional calculations in the regular relativistic approximation: Method, application to coinage metal diatomics, hydrides, fluorides and chlorides, and comparison with first-order relativistic calculations. J Chem Phys 1998. [DOI: 10.1063/1.476576] [Citation(s) in RCA: 639] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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47
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Fleig T, Marian CM. Relativistic ab-initio calculations on PdH and PdD: The rovibronic spectra and rotational splittings. J Chem Phys 1998. [DOI: 10.1063/1.475346] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [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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Activation of CH4, C2H6, C3H8, and c-C3H6 by gas-phase Pd+ and the thermochemistry of Pd-ligand complexes. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s0168-1176(97)00072-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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49
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Frankcombe KE, Cavell KJ, Yates BF, Knott RB. Competing Reaction Mechanisms for the Carbonylation of Neutral Palladium(II) Complexes Containing Bidentate Ligands: A Theoretical Study. Organometallics 1997. [DOI: 10.1021/om970063z] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Katrina E. Frankcombe
- Department of Chemistry, University of Tasmania, GPO Box 252-75, Hobart 7001, Tasmania, Australia
| | - Kingsley J. Cavell
- Department of Chemistry, University of Tasmania, GPO Box 252-75, Hobart 7001, Tasmania, Australia
| | - Brian F. Yates
- Department of Chemistry, University of Tasmania, GPO Box 252-75, Hobart 7001, Tasmania, Australia
| | - Robert B. Knott
- Australian Nuclear Science and Technology Organization, Private Mail Bag 1, MENAI, New South Wales 2234, Australia
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Martínez JM, Pappalardo RR, Marcos ES. Study of the Ag+ Hydration by Means of a Semicontinuum Quantum-Chemical Solvation Model. J Phys Chem A 1997. [DOI: 10.1021/jp970138c] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- José M. Martínez
- Departamento de Química Física, Facultad de Química, Universidad de Sevilla, 41012-Sevilla, Spain
| | - Rafael R. Pappalardo
- Departamento de Química Física, Facultad de Química, Universidad de Sevilla, 41012-Sevilla, Spain
| | - Enrique Sánchez Marcos
- Departamento de Química Física, Facultad de Química, Universidad de Sevilla, 41012-Sevilla, Spain
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