Clusters [Ma(GaCp*)b(CNR)c] (M = Ni, Pd, Pt): synthesis, structure, and Ga/Zn exchange reactions.

ABSTRACT

Reactions of homoleptic isonitrile ligated complexes or clusters of d(10)-metals with the potent carbenoid donor ligand GaCp* are presented (Cp* = pentamethylcyclopentadienyl). Treatment of [Ni4(CNt-Bu)7], [{M(CNR)2}3] (M = Pd, Pt) and [Pd(CNR)2Me2] (R = t-Bu, Ph) with suitable amounts of GaCp* lead to the formation of the heteroleptic, tri- and tetranuclear clusters [Ni4(CNt-Bu)7(GaCp*)3] (1), [{M(CNt-Bu)}3(GaCp*)4] (M = Pd 2a, Pt 2b), and [{Pd(CNR)}4(GaCp*)4] (R = t-Bu 3a, Ph 3b). The reactions involve isonitrile substitution reactions, GaCp* addition reactions, and cluster formation reactions. The new compounds were investigated for their ability to undergo Ga/Zn exchange reactions when treated with ZnMe2. The novel tetranuclear Zn-rich clusters [Ni4GaZn7(Cp*)2Me7(CNt-Bu)6] (4) and [{Pd(CNR)}4(ZnCp*)4(ZnMe)4] (R = t-Bu 5a, Ph 5b) were obtained and isolated. The electronic situation and geometrical arrangement of atoms of all compounds will be presented and discussed. All new compounds are characterized by solution (1)H, (13)C NMR and IR spectroscopy, elemental analysis (EA), liquid injection field desorption ionization mass spectrometry (LIFDI-MS) as well as single crystal X-ray crystallography.