Group VI Metal Carbonyl Complexes of Bis((diphenylphosphino)methyl)diphenylborate and an Assessment of Their Utility for Template Ligand Syntheses
详细信息    查看全文
文摘
Zerovalent group VI metal chemistry of anionic bis((diphenylphosphino)methyl)diphenylborate (Ph2BP2) offers some surprises in comparison to the chemistry of analogous complexes of neutral bidentate phosphines. The enhanced donor ability of Ph2BP2 relative to related bis-PPh2 ligands is confirmed by IR spectral analysis of [ASN][M(CO)4(Ph2BP2)] (ASN = 5-azoniaspiro[4.4]nonane; M = Cr, Mo, W). The mononitriles [ASN][fac-M(CO)3(RCN)(Ph2BP2)] (M = Cr, R = Me; M = Mo, R = Et; M = W, R = Et) are useful reagents for the introduction of sulfur dioxide and isocyanides to the 蟺-basic M(CO)3(Ph2BP2) fragment. While the fundamental coordination chemistry of this anionic fragment mostly mirrors that of its conventional neutral cousins, the electronic impact of Ph2BP2 leads to divergent reactivity in some cases. For example, the sulfur dioxide complexes [ASN][mer-M(CO)3(SO2)(Ph2BP2)] (M = Mo, W) are unreactive toward CH2N2, dramatically different from the case for mer-M(CO)3(SO2)(L2) (L2 = dppm, dppe, dppp). The spectral data of [ASN][Mo(CO)3(CNC6H4(2-NH2))(Ph2BP2)] and [ASN][Mo(CO)3(CNCH2CH2NH2)(Ph2BP2)], salts containing the first anions of 2-aminophenyl isocyanide and 2-aminoethyl isocyanide, respectively, indicate that the anionic M(CO)3(Ph2BP2) fragment may be more useful than neutral M(CO)3(dppe) for the 蟺-back-bonding induced stabilization of ligands prepared via template syntheses.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700