Expanding the Steric Coverage Offered by Bis(amidosilyl) Chelates: Isolation of Low-Coordinate N-Heterocyclic Germylene Complexes
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- 作者：Sean K. Liew ; S. M. Ibrahim Al-Rafia ; James T. Goettel ; Paul A. Lummis ; Sean M. McDonald ; Leah J. Miedema ; Michael J. Ferguson ; Robert McDonald ; Eric Rivard
- 刊名：Inorganic Chemistry
- 出版年：2012
- 出版时间：May 7, 2012
- 年：2012
- 卷：51
- 期：9
- 页码：5471-5480
- 全文大小：484K
- 年卷期：v.51,no.9(May 7, 2012)
- ISSN：1520-510X
文摘
The synthesis and coordination chemistry of a series of dianionic bis(amido)silyl and bis(amido)disilyl, [NSiN] and [NSiSiN], chelates with N-bound aryl or sterically modified triarylsilyl (SiAr<sub>3sub>) groups is reported. In order to provide a consistent comparison of the steric coverage afforded by each ligand construct, various two-coordinate N-heterocyclic germylene complexes featuring each ligand set were prepared and oxidative S-atom transfer chemistry was explored. In the cases where clean oxidation transpired, sulfido-bridged centrosymmetric germanium(IV) dimers of the general form [LGe(渭-S)]<sub>2sub> (L = bis(amidosilyl) ligands) were obtained in lieu of the target monomeric germanethiones with discrete Ge鈺怱 double bonds. These results indicate that the reported chelates possess sufficient conformational flexibility to allow for the dimerization of LGe鈺怱 units to occur. Notably, the new triarylsilyl groups (4-RC<sub>6sub>H<sub>4sub>)<sub>3sub>Si鈥?(R = <sup>tsup>Bu and <sup>isup>Pr) still offer considerably expanded degrees of steric coverage relative to the parent congener, 鈥擲iPh<sub>3,sub> and thus the use of substituted triarylsilyl groups within ligand design strategies should be a generally useful concept in advancing low-coordination main group and transition-metal chemistry.