Mesitylborane as a Bis(-B-H) Ligand: An Unprecedented Bonding Mode to a Metal Center
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- 作者：Gilles Alcaraz ; Eric Clot ; Ulrike Helmstedt ; Laure Vendier ; Sylviane Sabo-Etienne
- 刊名：Journal of the American Chemical Society
- 出版年：2007
- 出版时间：July 18, 2007
- 年：2007
- 卷：129
- 期：28
- 页码：8704 - 8705
- 全文大小：71K
- 年卷期：v.129,no.28(July 18, 2007)
- ISSN：1520-5126
文摘
The new borane complex RuH2(
DER=0 >2:2-H2BMes)(PCy3)2 (2) can be isolated in good yield by reaction of H2BMes with RuH2(2-H2)2(PCy3)2 (1) or alternatively, by reacting the chloro dihydrogen complex RuHCl(2-H2)(PCy3)2 (3) with lithium mesitylborohydride. 2 has been fully characterized by NMR and X-ray diffraction crystallography. A DFT/B3PW91 analysis shows that in 2, the H2BMes group is coordinated to the {RuH2(PCy3)2} fragment through two geminal 
-B-H bonds. This coordination involves -donation to the ruthenium and 
back-bonding from the ruthenium to the vacant p orbital of the boron. These two geminal -B-H bonds are responsible for the short Ru-B distance (1.938 (4) Å by X-ray, 1.957 Å by DFT).
DER=0 >2:2-H2BMes)(PCy3)2 (2) can be isolated in good yield by reaction of H2BMes with RuH2(2-H2)2(PCy3)2 (1) or alternatively, by reacting the chloro dihydrogen complex RuHCl(2-H2)(PCy3)2 (3) with lithium mesitylborohydride. 2 has been fully characterized by NMR and X-ray diffraction crystallography. A DFT/B3PW91 analysis shows that in 2, the H2BMes group is coordinated to the {RuH2(PCy3)2} fragment through two geminal -B-H bonds. This coordination involves -donation to the ruthenium and back-bonding from the ruthenium to the vacant p orbital of the boron. These two geminal -B-H bonds are responsible for the short Ru-B distance (1.938 (4) Å by X-ray, 1.957 Å by DFT).