Chemical and electrochemical synthesis, molecular structures, DFT calculations and optical properties of metal-chelates of 8-(2-tosylaminobenzilideneimino)quinoline

Abstract

Bis-chelate complexes with composition ML2 (M2+=Co, Ni, Cd and Zn) were synthesized on the basis of potential tridentate N, N, O donor Schiff base ligand – 8-(2-tosylaminobenzilideneimino)quinoline (HL) by both chemical (CS) and electrochemical synthesis (ES). CS of zinc complexes leads to obtaining the compounds with composition ZnLCOOCH3. Structure and properties of the prepared compounds have been studied by means of elemental analysis, IR, 1H NMR spectroscopy as well as quantum-chemical computations. Electronic spectra of UV–Vis absorption and photoluminescence for cadmium and zinc complexes were studied in acetonitrile solution. Crystal structure of zinc and cadmium complexes was determined by X-ray analysis. In the zinc complex ZnN6 coordination site was realized due to involving the nitrogen atom of quinoline fragment in coordination to the metal ion. Meanwhile due to X-ray analysis data cadmium complex possesses CdN6O surroundings with additional coordination of oxygen atom of tosylamino group from one of the ligand. Cobalt and zinc complexes were assigned to have the octahedral structures on the basis of the physical chemical measurements.