Reaction of CH2(Ph2PSe)2 (dppmSe2) with [Ru3(CO)12]. Fluxional behaviour of [Ru3(µ3-Se)2(CO)7(µ-dppm)] and crystal structures of [Ru4(µ4-Se)2(µ-CO)(CO)8(µ-dppm)]·MeOH and [Ru6(µ3-Se)4(CO)12(µ-dppm)2]·CH2Cl2

Abstract

The reaction of [Ru₃(CO)₁₂] with dppmSe₂ afforded the open-triangular nido cluster [Ru₃(µ₃-Se)₂(CO)₇(µ-dppm)] 1, the closo-octahedral species [Ru₄(µ₄-Se)₂(µ-CO)(CO)₈(µ-dppm)] 2 and the cubane-like cage [Ru₄(µ₃-Se)₄(CO)₁₀(µ-dppm)] 3. Multinuclear NMR data indicated a fluxional behaviour for 1 in solution consisting both in the reversible migration of a metal–metal bond in the cluster and in the oscillation of the methylene group of the dppm ligand. Pyrolysis of 1 gave the condensation derivative [Ru₆(µ₃-Se)₄(CO)₁₂(µ-dppm)₂] containing a central 64-electron butterfly core.