Mixed-ligand (triphenylphosphine)ruthenium complexes of diphenylcarborane by ligand manipulation and an asymmetric, bimolecular “symbiotic” cluster

Abstract

Deprotonation of [exo-5,6,10-{RuCl(PPh3)2}-5,6,10-(μ-H)3-nido-7,8-C2B9H9] (1a) and its C,C-diphenyl analogue (1b) affords the anions [3,3-(PPh3)2-3-Cl-closo-3,1,2-RuC2B9H11]− (2a) and [1,2-Ph2-3,3-(PPh3)2-3-Cl-closo-3,1,2-RuC2B9H9]− (2b), respectively. Dehalogenation of 2b in the presence of one equivalent of tBuNC yields [1,2-Ph2-3,3-(tBuNC)2-3-PPh3-pseudocloso-3,1,2-RuC2B9H9] (3), and if 2b is dehalogenated in the presence of CO a very similar compound, [1,2-Ph2-3,3-(CO)2-3-PPh3-pseudocloso-3,1,2-RuC2B9H9] (4), is formed. Treatment of 2b with Ag+ in the absence of a donor ligand affords, amongst a number of products, the compound [{1,2-Ph2-pseudocloso-3,1,2-RuC2B9H9}{1′,8′-Ph2-closo-2′,1′,8′-RuC2B9H9}] (5) in which two different {RuPh2C2B9H9} units both achieve electronic and coordinative saturation at their Ru centres by η6-coordination of a Ph ring on the other cluster in a symbiotic manner. Compounds 1b, 3, 4 and 5 were fully characterised, including by crystallographic studies.