Synthesis of trinuclear complexes with mixed bridging ligands. X-Ray structure of [Pd{Rh(µ-pz)(µ-SBut)(CO)2}2](pz = pyrazolate)

Abstract

The formation and properties of the trinuclear heterobridged complexes of general formula [Pd{Rh(µ-pz)(µ-SBu^t)L₂}₂][L₂= cycloocta-1,5-diene 1; L₂=(CO)₂2; L₂= CO, PPh₃3 and L₂= CO, P(OMe)₃4; pz = pyrazolate] are reported. Complexes 2 and 4 react with molecular iodine to give the compounds [Pd{Rh-(µ-pz)(µ-SBu^t)I₂L₂}₂][L₂=(CO)₂5 and L₂= CO, P(OMe)₃6]. The structure of [Pd{Rh(µ-pz)(µ-SBu^t)(CO)₂}₂]2 has been determined by X-ray diffraction methods. The trinuclear complex is centrosymmetric with the Pd atom lying on the centre of symmetry. The Rh and Pd atoms, separated by 3.686(1)Å, are connected by a double bridge, the pyrazolate ligand bridging through the two N atoms and the SBu^t ligand bridging through the S atom.