Structure, spectroscopy and DFT studies of a novel one-dimensional CuII-diphosphonate coordination polymer

By introducing the second ligand 2,2’-bipy, a new copper(II) diphosphonate [Cu(HL)(2,2′-bipy)] (HL = 1-hydroxyethylidenediphosphonate, 2,2′-bipy = 2,2′-bipyrimidine) has been hydrothermally synthesized and characterized by powder X-ray diffraction, elemental analysis, IR and TG-DTA. The single-crystal X-ray diffractions show that compound possess a three-dimensional supramolecular structure, built from 1D chain via a single-bridge O–P–O in syn-anti fashion based on mononuclear unit [CuON]. UV–vis spectra and the nature of electron transfer of are investigated, and the experimental results are in agreement with the quantum chemistry calculation using the B3LYP/6-31G* method. Fluorescent measurements reveal that two emission peaks of centered at 382.5 and 424.5 nm are mainly caused by intraligand *– emission state of the second ligands (375, 429.5 nm,  = 235 nm). Results of electrochemical studies (CV) indicate a higher donor ability of .