Rhodium(III) and Ruthenium(II) Complexes with a Pentadentate Tetrapodal Phosphine Ligand

Rhodium(III) and ruthenium(II) complexes supported by a pentadentate tetrapodal (pentaPod) phosphine ligand are synthesized through abstraction of one chloride ligand from initially obtained kappa(4)-pentaPod coordinated dichloro complexes [MCl2(kappa(4)-(P2PP2Ph)-P-Me)](+/0) (M=Rh(III), Ru(II)) with alkali salts of weakly coordinating anions. While for the rhodium kappa(5)-pentaPod complex the remaining, axial chloride ligand could not be replaced by di- or triatomic ligands, in case of ruthenium the complexes [Ru(CN)(kappa(5)-(P2PP2Ph)-P-Me]Al(pftb)(4) (5) and [Ru(N-3)(kappa(5)-(P2PP2Ph)-P-Me]Al(pftb)(4) (6) could be generated through ligand exchange. By comparison of NMR parameters and employing DFT calculations, additional insights into the electronic influence of different ligands (i. e., Cl-, CN-, N-3(-)) could be gained.

Automated summary

Rhodium(III) and ruthenium(II) complexes supported by a pentadentate tetrapodal phosphine ligand were synthesized, with insights gained into the electronic influence of different ligands. While the axial chloride ligand in the rhodium complex could not be replaced, new complexes were generated through ligand exchange in the case of ruthenium.