N-heterocyclic carbene and phosphine complexes of osmium and ruthenium carbonyls

Content Provider	Semantic Scholar
Author	Cooke, Craig E.
Copyright Year	2008
Abstract	1,3-bis-(2 ,4,6-trimethylphenyl )imidazol-2-yl idene-silver(1 )chloride ([IMes]AgCI), a carbene transfer agent, was employed in the reaction with various osmium clusters. Reaction of ([IMes]AgCI) with [Os3(j.l-Hh(CO)10] gave [Os3(j.l-H)(j.l-CI)(CO)g(IMes)] (1), an osmium N-heterocyclic carbene complex. The reaction of ([IMes]AgCI) with the cluster [OS3(CO)10(CH3CNh] yielded two products, [Os3(j.l-CI)(CO)1o(j.l-Ag(IMes)] (2) and [(I Mes-H)][Os3(IJ-C1)(CO)10](j.l4Ag)[OS3(j.l-CI)(CO)1O] (3). Compound (2) is a heterobimetallic carbene complex resulting from the complete incorporation of ([IMes]AgCI). Transmetalation of the IMes fragment resulted in the formation of [OS4(j.lH)4(CO)11(n'IMes)] (4) (n denotes normal carbene bonding) and [OS4(j.lH)4(CO)10(IMes)2] (5). Compound (5) was found to be sensitive to silica gel column chromatography in the presence of dichloromethane decomposing to [Os4(j.l-Hh(j.l-CI)(CO)11 (IMes)] (6) which possessed a butterfly metal skeleton. The ruthenium analogue of (4), [Ru4(j.l-H)4(CO)11(IMes)] (7), was prepared and found to be thermally unstable. Thermolysis of (4) in benzene yielded four products. The abnormal carbene complex [Os4(j.l-H)4(CO)11(a·IMes)] (9) (a denotes abnormal carbene bonding), an isomer of (4), and {Os4(j.l-H)(CO)10[(Il-C)N(Mes)C2H2NC6H2 (CH3h(1l2_C)(Il-C)C4H4(1l2-Cm (10), an unusual complex resulting from the activation of benzene, were isolated in modest yields. Two higher-nuclearity
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Language	English
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Content Type	Text
Resource Type	Article