First examples of neutral rhenium(V) complexes with a novel semi-rigid ligand containing a P,N,N,S donor atom set: Synthesis, characterisation and crystal structure

A new PN2S ligand, N-[2-(diphenylphosphino)phenyl]-2-[(S-trityl)acetylamino]ethanamide [Ph-P(Ph2)N2S(Trt)], was synthesised and reacted with ReV precursors. The reaction of both tritylated and detritylated ligands with ReOCl3(PPh3)2 gave the same expected neutral complex [ReO{Ph-P(Ph2)N2S}] (4) in good yield. An unexpected neutral and diamagnetic species, [ReN{Ph-P(Ph2)N2S(Trt)}] (5), has been isolated during the complexation of the tritylated ligand with ReNCl2(PPh3)2. The complexes, characterized by classical spectroscopic methods and X-ray analysis for 4, are the first examples of neutral semi-rigid-PN2S rhenium(V) complexes.

Graphical abstractThe synthesis of a novel PN2S-tetradentate ligand [Ph-P(Ph2)N2S(Trt)] (2) and its metal complexation with ReV precursors have been studied. Whilst the reaction of 2 with ReOCl3(PPh3)2 gave the expected stable complex [ReO{Ph-P(Ph2)N2S}] (4), an unexpected neutral and diamagnetic species, [ReN{Ph-P(Ph2)N2S(Trt)}] (5), has been isolated during the complexation of 2 with ReNCl2(PPh3)2.Figure optionsDownload full-size imageDownload as PowerPoint slide