Inter- and Intramolecular Rhodium-Rhodium Interactions in Bis-(bidentate isocyanide)rhodium(I) Hexafluorophosphates

Abstract

Abstract The reaction of [RhCl(1,5-C8H12)]2 with the stoichiometric amount of bidentate isocyanide followed by metathesis affords complexes of the types [Rh(L–L)2]PF6 (L–L=CN(CH2)8NC (1), CN(CH2)7NC (2)) and [Rh2(L–L)4](PF6)2 (L–L=CN(CH2)6NC (3), CN(CH2)4NC (4)). The electronic spectra at various concentrations reveal that in dilute solutions 1 and 2 exist as monomers with chelating isocyanides, while 3 and 4 form dimers with bridging isocyanides through intramolecular rhodium–rhodium interactions as the smallest unit. On the other hand, in concentrated solutions 1 and 2 form dimers and 4 tetramers through intermolecular Rh–Rh interactions.