Adducts ofo-Silaborane With Water and Methanol

Wesemann, Lars; Trinkaus, Michael; Ramjoie, Yves; Ganter, Beate; Englert, Ulli; Müller, Jens

doi:10.1002/(sici)1099-0682(200004)2000:4<735::aid-ejic735>3.0.co;2-v

Cited by 5 publications

(3 citation statements)

References 17 publications

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“…The arguments based on the compatibility of overlap between rings and caps must depend on the heteroatom involved. While silaboranes are still a novelty, replacement of the carbon atoms in carboranes by silicon must bring dramatic changes in its structure bonding and reactivity . Si with diffused orbitals fits better with larger rings.…”

Section: Resultsmentioning

confidence: 99%

“…The relative stability and aromaticity of 1,2-carboranes and dehydrogeno derivatives and their Si analogues are presented here to get further insight into the nature of these polyhedral systems when the bonding is disturbed by dehydrogenation. Recent developments in the chemistry of polyhedral carboranes and silaboranes and lack of similar attempts in smaller polyhedral structures prompted us to present the details of our study.…”

Section: Introductionmentioning

confidence: 99%

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Control of Stability through Overlap Matching: closo-Carborynes andcloso-Silaborynes

2002

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The matching of ring and cap orbitals for overlap is used to arrive at the best carborynes among the many possibilities. Accordingly, 1,2-carboranes, 1,2-silaboranes (C2BnHn+2, and Si2BnHn+2, n = 4, 5, 8, and 10), and their dehydrogeno derivatives were studied with use of the Density Functional Theory (B3LYP/6-311+G*). The dehydrogenation of 2,3-C2B5H7 (6a) to 2,3-C2B5H5 (13a) is estimated to be even less endothermic than those of benzene and 1,2- C2B10H12 (1a) to benzyne and 1,2-C2B10H10 (8a) by more than 21 kcal/mol. This is due to the extra stabilization gained through better overlap of the C2B3H3 ring with the 2 BH caps. The relatively larger size of the Si atom leads to overlap requirements in silaboranes that are different from those in carboranes. The lower Si-Si single bond energy and the preference of Si for lower coordination result in unusual structures in dehydrogenosilaboranes. One of the Si atoms moves away from the surface in Si2B10H10 (15), Si2B8H8 (16, 17, and 18), and 1,2-Si2B5H5 (19). One Si atom forms a bridge to a trigonal surface in 2,3-Si2B5H5 (20) and 1,2-Si2B4H4 (21). Estimates of three-dimensional aromaticity with NICS calculations show that the exohedral double bond does not influence three-dimensional aromaticity.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Control of Stability through Overlap Matching: closo-Carborynes andcloso-Silaborynes

2002

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“…Syntheses of main-group heteroboranes 1 have been dominated by carbaboranes 2 for decades but recently there has been intense research on heteroboranes with phosphorus, 3 nitrogen 4 and silicon 5 cluster atoms. A naked P vertex is isolobal with a CH vertex so phosphaboranes and phosphacarbaboranes are structural analogues of the corresponding carbaboranes.…”

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confidence: 99%