X-ray diffraction, Raman spectroscopic, and solid-state NMR studies of the group 14 metal-(tetracarbonyl)cobalt complexes Ph3MCo(CO)4 (M = Si, Sn, Pb)

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作者：

JM Geller，JH Wosnick，IS Butler，DF Gilson，F Bélanger-Gariépy

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摘要：

Single-crystal X-ray diffraction studies illustrate that the three title compounds are isomorphous, belonging to the triclinic space group , with slightly distorted trigonal bipyramidal geometry about cobalt. The solid-state Si, Sn, and Pb cross-polarization magic angle spinning (CP MAS) NMR spectra are presented. The indirect spin spin coupling constant (), quadrupolar dipolar shift (), direct dipolar coupling constant (), anisotropy in spin spin coupling (Delta), and the chemical shift tensor were extracted. A plot of the reduced coupling constant vs. -electron densities at the nucleus indicates that the Fermi contact term may be dominant for the tin and lead complexes; however, the large Deltafor all complexes indicate that there are also significant anisotropic terms. Trends in the Raman scattering spectra are also discussed.: Si, Sn, and Pb CP MAS NMR, tetracarbonyl cobalt, spin spin coupling, chemical shift tensor, quadrupole coupling, Fermi contact, cobalt group 14.

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关键词：

29 Si 119 Sn and 207 Pb CP MAS NMR tetracarbonyl cobalt spin spin coupling chemical shift tensor quadrupole coupling Fermi contact cobalt group 14 RMN