الفهرس | Only 14 pages are availabe for public view |
Abstract In the present study, two hydrazone ligands, HLa and HLb, were efficiently synthesized from the condensation of 2-aminochromone-3-carboxaldehyde (ACC) with equimolar amounts of semicarbazide hydrochloride and N4-phenylthiosemicarbazide; respectively. The absorption and fluorescence characteristics of ACC, HLa and HLb were recorded in eleven different solvents with increasing polarities at room temperature. The two ligands reacted with Cu(II) metal ion with different anions (OAc–, NO3–, SO42–,SCN–,and Cl) in absence and presence of auxiliary ligands (L′); N,O-donor; or N,N-donor. The obtained results showed that the ligand behaves as a neutral/monoanionic tridentate O2N and NOS for HLa and HLb; respectively, forming chelates with molar ratio: 1:1 (M:L) and 1:1:1(M:L:L′) for ternary complexes. The hydrazones ligands and its metal complexes were fully characterized by analytical and spectral techniques in addition to thermal, conductivity and magnetic susceptibility measurements. The metal complexes exhibited square planar and octahedral geometrical arrangements according to the nature of the anion. The compounds exhibit luminescence property; promising interesting potential applications as photoactive materials. The ground state (µg) and excited state (µe) dipole moments are estimated from solvatochromic shifts of absorption and fluorescence spectra as a function of the dielectric constant (Ɛ) and refractive index (n) by using Bilot–Kawski, Lippert–Mataga, Bakhshiev, Kawski–Chamma–Viallet and Reichardt correlation methods. Excited state dipole moment is observed as larger than the ground state dipole moment. The molecular structural parameters of the ligands and its Cu(II) complexes have been calculated on the basis of DFT level implemented in the Gaussian 09 program at the B3LYP/6-31G(d,p) level and the theoretical data are correlated with the experimental data. The antibacterial properties of the ligands and its complexes have been screened against selected kinds of bacteria and fungi. |