Reactions of .alpha.,.beta.-unsaturated imines with di-.mu.-hydro-decacarbonyltriosmium including the dehydrogenation of an isopropyl group

Abstract

The unsaturated imine (CH/sub 3/)/sub 2/C=CHC(CH/sub 3/)=NC/sub 6/H/sub 5/ was found to react with (..mu..-H)/sub 2/Os/sub 3/(CO)/sub 10/ to produce the compounds (..mu..-H)/sub 2/(..mu../sub 3/-eta/sup 2/-(CH/sub 3/)/sub 2/CHCC(CH/sub 3/)=NC/sub 6/H/sub 5/)Os/sub 3/(CO)/sub 9/, A, and (..mu..-H)/sub 2/(..mu../sub 3/-eta/sub 4/-CH/sub 2/C(CH/sub 3/)CC(CH/sub 3/)=NC/sub 6/H/sub 5/)Os/sub 3/(CO)/sub 8/, B. Both products have been characterized crystallographically by using diffractometer data. For A, the space group is P2/sub 1//c (C/sup 5//sub 2h/), No. 14, with a = 14.818 (5) A, b = 9.051 (5) A, c = 20.098 (6) A, ..beta.. = 108.45 (3)/sup 0/, Z = 4, and rho/sub calcd/ = 2.59 g/cm/sup 3/. The structure was solved by the heavy-atom method and refined to the final residuals R/sub 1/ = 0.058 and R/sub 2/ = 0.067. For B, the space group is P2/sub 1//c (C/sup 5//sub 2h/), No. 14 with a = 16.060 (5) A, b = 8.820 (4) A, c = 16.809 (4) A, ..beta.. = 98.83 (2)/sup 0/, Z = 4, and rho/sub calcd/ = 2.703 g/cm/sup 3/. This structure was also solved by the heavy atom method and refined to the final residuals R/sub 1/ = 0.037 and R/sub 2/ = 0.041. A contains a ..mu../sub 3/-eta-(CH/sub 3/)/sub 2/CHCC(CH/submore » 3/)=NC/sub 6/H/sub 5/ ligand bridging one face of a triangular cluster of osmium atoms. The nitrogen atom is terminally bonded to one osmium atom while the ..cap alpha..-carbon serves as a bridge across the two remaining osmium atoms. The hydrogen atom on the ..cap alpha..-carbon has been removed and one has been added to the ..beta..-carbon, thus forming an isopropyl group. B contains a ..mu../sub 3/-eta/sup 2/-CH/sub 2/C(CH/sub 3/)CC(CH/sub 3/)=NC/sub 6/H/sub 5/ ligand bridging one face of a triangular cluster of osmium atoms. A terminally coordinated nitrogen atom is again bonded to one osmium atom. The ..cap alpha..-carbon bridges the two remaining osmium atoms. The ..cap alpha..- and ..gamma..-carbon atoms have each lost one hydrogen atom. Together with the ..beta..-carbon atom they are bonded in the form of a ..pi..-allyl group to one osmium atom.« less