Rhenium(III) and rhenium(V) complexes stabilized by the potentially tetradentate ligand tris(2-diphenylphosphinoethyl)amine

The reaction of the rhenium(V) nitrido complex [Re(N)Cl2(PPh3)2] with the tripodal ligand N(CH2CH2PPh2)3 (NP3) in THF gave [Re(N)Cl2(η2-P,P-NP3)] (1) in which NP3 acts as a tridentate ligand using the nitrogen and two phosphorus donors for coordination. Refluxing 1 in a polar solvent such as ethanol produced [(η4-NP3)Re(N)Cl]Cl (2) in which NP3 acts as a tetradentate ligand. Treatment of complex [Re(O)Cl3(AsPh3)2] containing the [ReO]3+ core with NP3 in THF yielded [ReCl3{η3-N,P,P-(N{CH2CH2Ph2}2{CH2CH2P(O)Ph2})}] (3). Complexes 1 and 3 have been characterized by single-crystal X-ray analyses.