ReVO and ReVNPh complexes with pentadentate benzamidines – Synthesis, structural characterization and DFT evaluation of isomeric complexes

Novel, potentially pentadentate ligands (H3L) for an optimal coordination of {MVO}3+ and {MV(NPh)}3+ cores (M = Re, Tc) have been tailored by a computer-aided procedure. They can be prepared by reactions of 2-aminobenzyliminodiacetic acid diethylester with N,N-[(dialkylamino)(thiocarbonyl)]benzimidoyl chlorides and subsequent hydrolysis. The ligands react with [ReOCl3(PPh3)2] or [Re(NPh)Cl3(PPh3)2] under triple deprotonation and form compounds of the general compositions [ReO(L)] and [Re(NPh)(L)], respectively. The organic ligands occupy the remaining five coordination positions of the {ReO}3+ and {Re(NPh)}3+ cores in all compounds studied. The phenylimido complexes hydrolyze in basic media under formation of their oxidorhenium(V) analogs.

Graphical abstractA novel family of pentadentate ligands for nuclearmedical procedures has been developed and optimized by a computer-aided procedure. The resulting SN2O2 ligands form very stable complexes with {ReO}3+ units.Figure optionsDownload full-size imageDownload as PowerPoint slide