Cluster chemistry. Part 92. Directed syntheses and crystal structures of [{Ru3(CO)11}{µ-PPh2[C2CO2(CO)6]C2}{Ru2-(µ-PPh2)(CO)6}]·CH2Cl2, [{Os3(CO)11}(µ-PPh2C2C2){Co2Os3-(µ-PPh2)(CO)13}] and [Co2Os3Re{µ6-C2Cch (PPh2)}-(µ-PPh2)(µ-CO)2(CO)14·CH2Cl2

Abstract

Reactions of [Co₂(CO)₈] with [{M_n(CO)₁₁}₂(µ-bdpp)][M_n Ru₃, Os₃, Re₃(µ-H)₃ or Ru₄(µ-H)₄; bdpp PPh₂C₂C₂PPh₂] afforded [{M_n(CO)₁₁}₂{µ-PPh₂[C₂Co₂(CO)₆]C₂ PPh₂}][M_n Ru₃1, Os₃2, Re₃(µ-H)₃3 or Ru₄(µ-H)₄4] in which the Co₂(CO)₆ moiety bonds to one of the CC triple bonds of the bridging bdpp ligand. Pyrolysis of 1 yielded [{Ru₃(CO)₁₁}{µ-PPh₂[C₂Co₂(CO)₆]C₂}{Ru₂(µ-PPh₂)(CO)₆}]5, which is formed by concomitant addition of a P–C(sp) bond to one Ru₃ cluster and elimination of a Ru(CO)₄ fragment. In [{Os₃(CO)₁₁}(µ-PPh₂C₂C₂){Co₂Os₃(µ-PPh₂)(CO)₁₃}]8, obtained by heating 2, the Co₂Os₃ cluster consists of three edge-sharing triangles; the C₂ fragment interacts with all five metal atoms. Reaction of the mixed-metal complex [{Os₃(CO)₁₁}(µ-bdpp){Re₃(µ-H)₃(CO)₁₁}]10 with [Co₂(CO)₈] yielded a 1:1 isomeric mixture of [{Os₃(CO)₁₁}{µ-PPh₂[C₂Co₂(CO)₆]C₂PPh₂}{Re₃(µ-H)₃(CO)₁₁}]11a and [{Re₃(µ-H)₃(CO)₁₁}{µ-PPh₂[C₂Co₂(CO)₆]C₂PPh₂}{Os₃(CO)₁₁}]11b. Pyrolysis of 11a afforded [Co₂Os₃Re{µ₆-C₂CCH(PPh ₂)}(µ-PPh₂)(µ-CO)₂(CO)₁₄]12 in which all three transition metals form a cluster about the C₄P fragment of the original bdpp ligand, which has also added one H atom to the carbon adjacent to the PPh₂ group. The second PPh₂ group bridges an Os–Os bond. Molecular structures of 5, 8 and 12 were determined by X-ray crystallography.