Alkinyl-substituierte Chlorsilane als Clusterbausteine

Article abstract of DOI:10.1016/0022-328X(91)80197-R

The reaction of phenylethynyl-substituted chlorosilanes with dicobaltoctacarbonyl is discussed.Co2(CO)8 (II) yields selectively with (R)(PhC<*>C)Si(H)(Cl) (R = Me: I; R = C<*>CPh: V) (R)<(η²-C<*>CPh)Co2(CO)6>Si(H)(Cl) (R = Me: III; R = C<*>CPh: VI), in which the phenylethynyl group is η² side-on co-ordinated to "Co2(CO)6".III affords with further Co2(CO)8 under oxidative addition (Me)<(η²-C<*>CPh)Co2(CO)6>Si(Cl) (IV); IV may also be obtained directly by the reaction of I with 1.5 equivalents of II.VI contains a non-coordinated C<*>CPh group and yields with one equivalent of II the tetranuclear complex <(η²-C<*>CPh)Co2(CO)6>2Si(H)(Cl) (VII) in which the two C<*>CPh ligands form sterically-hindered carbon-cobalt tetrahedrane cluster units.Compounds VIII and X show the same reaction behaviour as I and V: (R)(PhC<*>C)Si(Cl)2 (R = Ph:VIII; R = H:X) reacts with one equivalent of II to yield in the first step (R)<(η²-C<*>CPh)Co2(CO)6>Si(Cl)2 (R = Ph:IX; R = H:XI).Addition of 0.5 parts of II to XI affords in high yields complex <(η²-C<*>CPh)Co2(CO)6>Si(Cl)2 (XII).In a similar manner, compound (Me)(PhC<*>C)Si(H)2 (XIII) yields with one equivalent of II the dinuclear complex (Me)<(η²-C<*>CPh)Co2(CO)6>Si(H)2 (XIV) which slowly decompose to form oligomeric compounds as well as (η²-PhC<*>CH)Co2(CO)6 (XV).All new compounds were characterized by analytical and spectroscopic data (IR, 1H, 13C NMR, MS), and (Me)<(η²-C<*>CPh)Co2(CO)6>Si(Cl) (IV) by X-ray analysis.