ISSN:
0020-7608
Schlagwort(e):
Computational Chemistry and Molecular Modeling
;
Atomic, Molecular and Optical Physics
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Germanium chemical shifts were studied theoretically by the ab initio molecular orbital method. The compounds studied were GeMe4-xClx and GeMe4-xHx(x = 0-4). The calculated values of the germanium chemical shifts agreed well with the available experimental values. The germanium chemical shift is due to the p-electron mechanism that reflects the ligand electronic effect on the p-p* excitation term in the second-order paramagnetic term. For GeMe4-xHx, the chemical shift is almost linear to the number of the ligand, x. On the other hand, a U-shaped dependence is predicted for the chemical shifts of the GeMe4-xClx series and is shown to be caused by the strong and nonadditive electron-withdrawing ability of the Cl ligand. The diamagnetic contribution is relatively small for the chemical shift and is determined solely by a structural factor. © 1994 John Wiley & Sons, Inc.
Zusätzliches Material:
5 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/qua.560490316
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