151
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Manninen P, Lantto P, Vaara J, Ruud K. Perturbationalab initiocalculations of relativistic contributions to nuclear magnetic resonance shielding tensors. J Chem Phys 2003. [DOI: 10.1063/1.1586912] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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152
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Lichtenberger DL. Electron Distribution, Bonding, and J(Si−H) NMR Coupling Constant in (η5-C5H5)(CO)2MnHSiCl3: The Molecular Orbital View. Organometallics 2003. [DOI: 10.1021/om030121i] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dennis L. Lichtenberger
- Center for Gas-Phase Electron Spectroscopy, Department of Chemistry, The University of Arizona, Tucson, Arizona 85721
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153
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Jokisaari J, Autschbach J. 13C–77Se and77Se–77Se spin–spin coupling tensors in carbon diselenide: NMR experiments and ZORA DFT calculations. Phys Chem Chem Phys 2003. [DOI: 10.1039/b305442j] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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154
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Gee M, Wasylishen RE, Ragogna PJ, Burford N, McDonald R. Characterization of indirect 31P-31P spin-spin coupling and phosphorus chemical shift tensors in pentaphenylphosphinophosphonium tetrachlorogallate, [Ph3P-PPh2][GaCl4]. CAN J CHEM 2002. [DOI: 10.1139/v02-178] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Phosphorus chemical shift and 31P,31P spin-spin coupling tensors have been characterized for pentaphenylphosphinophosphonium tetrachlorogallate, [Ph3P-PPh2][GaCl4], using solid-state 31P NMR spectroscopy. Spectra obtained with magic-angle spinning yield the isotropic value of the indirect spin-spin coupling, |1J(31P,31P)iso|, 323 ± 2 Hz, while 2D spin-echo and rotational resonance experiments provide the effective dipolar coupling constant, Reff, 1.70 ± 0.02 kHz, and demonstrate that Jiso is negative. Within experimental error, the effective dipolar coupling constant and Jiso are unchanged at 120°C. The anisotropy in 1J(31P,31P), ΔJ, has been estimated by comparison of Reff and the value of the dipolar coupling constant, RDD, calculated from the PP bond length as determined by X-ray diffraction. It is concluded that |ΔJ| is small, with an upper limit of 300 Hz. Calculations of 1J(31P,31P) for model systems H3P-PH+2 and (CH3)3P-P(CH3)+2 using density functional theory as well as multiconfigurational self-consistent field theory (H3P-PH+2) support this conclusion. The experimental spin-spin coupling parameters were used to analyze the 31P NMR spectrum of a stationary powder sample and provide information about the phosphorus chemical shift tensors. The principal components of the phosphorus chemical shift tensor for the phosphorus nucleus bonded to three phenyl groups are δ11 = 36 ppm, δ22 = 23 ppm, and δ33 = 14 ppm with an experimental error of ±2 ppm for each component. The components are oriented such that δ33 is approximately perpendicular to the PP bond while δ11 forms an angle of 31° with the PP bond. For the phosphorus nucleus bonded to two phenyl groups, the principal components of the phosphorus chemical shift tensor are δ11 = 23 ppm, δ22 = 8 ppm, and δ33 = 68 ppm with experimental errors of ±2 ppm. In this case, δ33 is also approximately perpendicular to the PP bond; however, δ22 is close to the PP bond for this phosphorus nucleus, forming an angle of 13°. The dihedral angle between the δ33 components of the two phosphorus chemical shift tensors is 25°. Results from ab initio calculations are in good agreement with experiment and suggest orientations of the phosphorus chemical shift tensors in the molecular frame of reference.Key words: Nuclear magnetic resonance spectroscopy, phosphorus chemical shift tensors, 31P-31P J-coupling tensors, density functional theory, multiconfigurational self-consistent field theory, phosphinophosphonium salts.
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155
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Lantto P, Vaara J, Helgaker T. Spin–spin coupling tensors by density-functional linear response theory. J Chem Phys 2002. [DOI: 10.1063/1.1502243] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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156
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Jokisaari J, Järvinen S, Autschbach J, Ziegler T. 199Hg Shielding Tensor in Methylmercury Halides: NMR Experiments and ZORA DFT Calculations. J Phys Chem A 2002. [DOI: 10.1021/jp025797q] [Citation(s) in RCA: 30] [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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157
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Barone V, Peralta JE, Contreras RH, Snyder JP. DFT Calculation of NMR JFF Spin−Spin Coupling Constants in Fluorinated Pyridines. J Phys Chem A 2002. [DOI: 10.1021/jp020212d] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Verónica Barone
- Departamento de Física, FCEyN, Universidad de Buenos Aires, Buenos Aires, Argentina, and Department of Chemistry, Emory University, Atlanta, Georgia 30322
| | - Juan E. Peralta
- Departamento de Física, FCEyN, Universidad de Buenos Aires, Buenos Aires, Argentina, and Department of Chemistry, Emory University, Atlanta, Georgia 30322
| | - Rubén H. Contreras
- Departamento de Física, FCEyN, Universidad de Buenos Aires, Buenos Aires, Argentina, and Department of Chemistry, Emory University, Atlanta, Georgia 30322
| | - James P. Snyder
- Departamento de Física, FCEyN, Universidad de Buenos Aires, Buenos Aires, Argentina, and Department of Chemistry, Emory University, Atlanta, Georgia 30322
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158
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Ab initio characterization of through-space indirect nuclear spin–spin coupling tensors for fluorine-X (X=F, C, H) spin pairs. J Mol Struct 2002. [DOI: 10.1016/s0022-2860(01)00725-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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159
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Patchkovskii S, Autschbach J, Ziegler T. Curing difficult cases in magnetic properties prediction with self-interaction corrected density functional theory. J Chem Phys 2001. [DOI: 10.1063/1.1370527] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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160
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Yang SY, Leung WH, Lin Z. Geometric Features and Electronic Structures of Six-Coordinated Dialkyl and Dithiolate Complexes of Osmium(IV) Porphyrins. Organometallics 2001. [DOI: 10.1021/om010149z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sheng-Yong Yang
- Department of Chemistry, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Wa-Hung Leung
- Department of Chemistry, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Zhenyang Lin
- Department of Chemistry, The Hong Kong University of Science and Technology, Hong Kong, China
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161
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Autschbach J, Ziegler T. A theoretical investigation of the remarkable nuclear spin-spin coupling pattern in [(NC)(5)Pt-Tl(CN)](-). J Am Chem Soc 2001; 123:5320-4. [PMID: 11457395 DOI: 10.1021/ja003866d] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We address the problem of the interpretation of heavy nucleus spin-spin couplings for systems being studied in solution. Solvation can create counterintuitive features concerning the spin-spin couplings, which are enhanced by relativistic effects due to the presence of heavy nuclei. This should therefore be taken into consideration for the discussion of spectra obtained from solution. Evidence for such solvent effects is provided by a relativistic density functional study of [(NC)(5)Pt-Tl(CN)](-) (I). It is demonstrated that the remarkable experimentally observed spin-spin coupling pattern, e.g., (2)J(Tl-C) >> (1)J(Tl-C) and J(Pt-Tl) approximately 57 kHz, is semiquantitatively reproduced by our calculations if both relativistic effects and solvation are taken into account. Solvent effects are very substantial and shift the Pt-Tl coupling by more than 100%, e.g. Relativistic increase of s-orbital density at the heavy nuclei, charge donation by the solvent, and the specific features of the multicenter C-Pt-Tl-C bond are responsible for the observed coupling pattern.
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Affiliation(s)
- J Autschbach
- Contribution from the Department of Chemistry, The University of Calgary, Alberta T2N 1N4, Canada.
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162
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Autschbach J, Ziegler T. Solvent effects on heavy atom nuclear spin-spin coupling constants: a theoretical study of Hg-C and Pt-P couplings. J Am Chem Soc 2001; 123:3341-9. [PMID: 11457070 DOI: 10.1021/ja003481v] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The computation of indirect nuclear spin-spin coupling constants, based on the relativistic two-component zeroth order regular approximate Hamiltonian, has been recently implemented by us into the Amsterdam Density Functional program. Applications of the code for the calculation of one-bond metal-ligand couplings of coordinatively unsaturated compounds containing (195)Pt and (199)Hg, including spin-orbit coupling or coordination effects by solvent molecules, show that relativistic density functional calculations are able to reproduce the experimental findings with good accuracy for the systems under investigation. Spin-orbit effects are rather small for these cases, while coordination of the heavy atoms by solvent molecules has a great impact on the calculated couplings. Experimental trends for different solvents are reproduced. An orbital-based analysis of the solvent effect is presented. The scalar relativistic increase of the coupling constants is of the same order of magnitude as the nonrelativistically obtained values, making a relativistic treatment essential for obtaining quantitatively correct results. Solvent effects can be of similar importance.
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Affiliation(s)
- J Autschbach
- Department of Chemistry, The University of Calgary, Alberta T2N 1N4, Canada.
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