NH3-promoted ligand lability in eleven-vertex rhodathiaboranes

Abstract

NH3 reacts with nido-[(PPh3)2RhSB9H10] to give an equilibrium with nido-[(NH3)(PPh3)2RhSB9H10] that involves ammonia coordination and dissociation. At higher concentrations of NH3, the {Rh(NH3)(PPh3)2} adduct undergoes PPh3 ligand dissociation giving new NH3-ligated species which are in equilibrium. This system evolves to form a hydridorhodathiaborane that features a H3N−B group. All the proposed NH3-ligated clusters feature weak-bonding interactions with ammonia closing a rare stoichiometric cycle of NH3 addition to/release from polyhedral boron-containing compounds.