Treatment of the pentamethylcyclopentadienylruthenium chloride tetramer [Cp*RuCl]4 with bis(dimethylphosphino)methane (dmpm) in tetrahydrofuran affords three ruthenium(II) phosphine complexes, Cp*Ru(dmpm)Cl, [Cp*Ru(dmpm)(η1-dmpm)]Cl, and Cp*2Ru2(μ-dmpm)2-Cl2. Similar treatment of [Cp*RuCl]4 with bis(diphenylphosphino)methane (dppm) in tetrahydrofuran or diethyl ether affords the dinuclear species Cp*2Ru2(μ-dppm)(μ-Cl)2; in acetonitrile, this same reaction yields the mononuclear product Cp*Ru(dppm)Cl in high yield. The mononuclear complexes Cp*Ru(P-P)Cl (where P-P is dmpm or dppm) can be alkylated with dimethylmagnesium in diethyl ether to give the methyl complexes Cp*Ru(dmpm)Me and Cp*Ru(dppm)Me. Protonation of these Cp*Ru(P-P)Me complexes with trifluoroacetic acid results in the rapid reductive elimination of methane and formation of the trifluoroacetato complexes Cp*Ru(P-P)(η1-O2CCF3); no ruthenium(IV) hydridomethyl intermediates could be detected. Treatment of Cp*2Ru2(dppm)2Cl2 with LiAlH4 in diethyl ether yields the ruthenium aluminohydride complex Cp*2Ru2(μ-dppm)(μ-AlH5), which can be converted to the ruthenium polyhydride complex Cp*2Ru2(μ-dppm)H6 by treatment with methanol at low temperatures. The crystal structure of Cp*2Ru2(μ-dppm)(μ-AlH5) shows that the aluminohydride unit is bound in a (μ-H)2AlH(μ-H)2 fashion.
|Original language||English (US)|
|Number of pages||8|
|State||Published - Jun 24 1997|
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry