Abstract
Three new reduced amino-acid Schiff-base complexes, [Zn(HL)2] · H2O (1), [Ni(HL)2] · H2O (2), and [Cd(HL)2] · H2O (3), where H2L is a reduced Schiff base derived from condensation of N-(2-hydroxybenzaldehyde) and L-histidine, have been synthesized and characterized by elemental analysis, UV-Vis absorption spectra and single crystal X-ray diffraction. Complexes 1–3 are isostructural. All metal centers are six-coordinate with O2N4 donor sets in slightly distorted octahedra. Unlike its Schiff-base counterpart, the deprotonated monoanionic ligand HL− has a more flexible backbone and two HL− are tridentate to one metal. Moreover, the binding interactions of these complexes with calf thymus DNA (CT-DNA) have been investigated by UV-Vis spectra and fluorescence quenching, which show that the complexes bind in an intercalative mode.
Acknowledgement
This work was supported by the National Natural Science Foundation of China (No. 20771063).