Redox-catalysed isomerisation of [Rh2(µ-CO)(bipy)(Ph2PCH2CH2PPh2)(µ-N1,N3-RNNNR)2]2+to [Rh2(µ-CO)(bipy)(Ph2PCH2CH2PPh2)(µ-N1,3,N3-RNNNR)(µ-N1,N3-RNNNR)]2+(bipy = 2,2′-bipyridyl, R =p-tolyl); an unprecedented bonding mode for the bridging triazenide ligand

Abstract
Treatment of [Rh2(µ-CO)(bipy)(dppe)(µ-N1,N3-RNNNR)2]2+12+[bipy = 2,2′-bipyridyl, dppe = 1,2-bis(diphenylphosphino)ethane, R =p-tolyl] with a catalytic amount of [NBun 4][BH4] gave [Rh2(µ-CO)-(bipy)(dppe)(µ-N1,3,N3-RNNNR)(µ-N1,N3-RNNNR)]2+32+ X-ray studies on which show one ‘normal’ bridging triazenide ligand and one in which one of the terminal N atoms binds one Rh atom while the second bonds to both metal atoms; the triazenide ligands of 32+ are cis-bound to one metal centre and trans-bound to the second.