Rhenium(V) Complexes with Pentadentate P,N,O Ligands

Novel rhenium(V) complexes were isolated from reactions of [NBu4][ReOCl4] with the potentially pentadentate Schiff base PhP{C6H4-2-(HCN(C6H4-2-OH))}2, H2L1, and the corresponding amine PhP{C6H4-2-(CH2−NH(C6H4-2-OH))}2, H4L2. While the Schiff base undergoes partial hydrolytic decomposition and a redox reaction, the amine remains intact and acts as a pentadentate ligand, which encapsulates the metal atom of the {ReVO}3+ core or stabilizes a {ReVCl}4+ center by the formation of an imido-type ligand system.