Organogallium- and organozinc-rich palladium and platinum clusters

Abstract

The heteroleptic, binuclear compounds [M₂(GaCp*)₃(PMe₃)₂] (M = Pd: 1a, Pt: 1b, Cp* = pentamethylcyclopentadienyl) can be obtained if [Pd₂(dvds)₃] (dvds = 1,3-divinyl-1,1,3,3-tetramethyldisiloxane) or [Pt(COD)₂] (COD = cyclooctadiene) were treated with a 3 : 2 ratio of GaCp* and PMe₃. A trinuclear complex [Pd₃(GaCp*)₃(PMe₃)₃] (2) was isolated from in situ prepared [Pd(PMe₃)₂Me₂] and treatment with GaCp*. The new complexes were used as starting compounds for selective Ga/Zn exchange reactions to afford the dinuclear palladium compound [Pd₂(ZnCp*)(ZnMe)₃(PMe₃)₅] (3a) and the mononuclear platinum compound [Pt(ZnCp*)₂(ZnMe)₂(PMe₃)₂] (3b). The effects of a final transition metal count in organozinc ligated compounds and stabilization of Lewis acidic fragments like [Pd(PPh₃)₃], [Ni(C₂H₄)₃] or [Mo(CO)₅] were presented and discussed. All compounds have been fully characterized by ¹H, ¹³C, and ³¹P NMR spectroscopy, mass spectrometry using a liquid injection field desorption ionization (LIFDI) method, elemental analysis, and single crystal X-ray diffraction studies and the coordination polyhedra were analysed by the method of continuous shape measure (CShM).