Synthesis, characterization and DFT calculations of N,O Schiff base complex of copper(II)

Mononuclear copper(II) complex of the Schiff base, 2-methoxy-6-(3-morpholinopropyl-iminomethyl) phenol, [Cu(HL) 2 ](ClO 4 ) 2 ].H 2 O (1) has been synthesized and characterized by elemental analysis and different spectroscopic techniques. The structure of (1) is confirmed by single crystal X-ray diffraction analysis. The complex (1) crystallizes in the monoclinic space group P21/n. The crystal structure of the mononuclear complex exhibits two Schiff base ligands bound to the copper atom and two perchlorate ions as non-coordinating species. Both the ligands in (1) are zwitterions where nitrogen atom of the morpholine ring is protonated. Fluorescence spectral study shows that HL displays an emission band at 535 nm on excitation at 418 nm. The presence of Cu 2+ ion in complex (1) quenches its emission intensity. DFT and TDDFT calculations have been carried out to investigate the spectral transitions.