Unpredicted concurrency between P,P-chelate and P,P-bridge coordination modes of 1,5-diR-3,7-di(pyridine-2-y1)-1,5-diaza-3, 7-diphosphacyclooctane ligands in copper(I) complexes

Several new mono- and binuclear copper(I) complexes of pyridyl containing 1,5-diaza-3,7-diphosphacyl-cooctanes with bis-P,P-chelate and unusual P,P-bridged coordination modes of heterocyclic ligands were obtained and characterized. The 1,5-diaza-3,7-diphosphacyclooctane, containing p-tolyl substituents at nitrogen atoms forms bis-P,P-chelate mononuclear as well as metalacyclic binuclear complexes with P, P-bridged coordination mode of a ligand, whereas the N-1-phenylbezyl substituted ligand gives the expected P,P-chelate complexes only. Reasons for the differences in coordination modes have been found in the ligands geometry, where configuration of nitrogen atoms plays an important role. (C) 2017 Elsevier Ltd. All rights reserved.