Synthesis, physicochemical studies, embryos toxicity and DNA interaction of some new Iron(II) Schiff base amino acid complexes
作者:Laila H. Abdel-Rahman、Rafat M. El-Khatib、Lobna A.E. Nassr、Ahmed M. Abu-Dief
DOI:10.1016/j.molstruc.2013.02.023
日期:2013.5
New Fe(II) Schiff base amino acid complexes derived from the condensation of o-hydroxynaphthaldehyde with L-alanine, L-phenylalanine, L-aspartic acid, L-histidine and L-arginine were synthesized and characterized by elemental analysis, IR, electronic spectra, and conductance measurements. The stoichiometry and the stability constants of the complexes were determined spectrophotometrically. The investigated Schiff bases exhibited tridentate coordination mode with the general formulae [Fe(HL)(2)]center dot nH(2)O for all amino acids except L-histidine. But in case of L-histidine, the ligand acts as tetradentate ([FeL(H2O)(2)]center dot 2H(2)O), where HL = mono anion and L = dianion of the ligand. The structure of the prepared complexes is suggested to be octahedral. The prepared complexes were tested for their toxicity on chick embryos and found to be safe until a concentration of 100 mu g/egg with full embryos formation. The interaction between CF-DNA and the investigated complexes were followed by spectrophotometry and viscosity measurements. It was found that, the prepared complexes bind to DNA via classical intercalative mode and showed a different DNA cleavage activity with the sequence: nhi > nari > nali > nasi > nphali. The thermodynamic Profile of the binding of nphali complex and CF-DNA was constructed by analyzing the experimental data of absorption titration and UV melting studies with the McGhee equation, van't Hoff's equation, and the Gibbs-Helmholtz equation. (C) 2013 Elsevier B.V. All rights reserved.
Synthesis and structural characterisation of new Re(III) complexes using aldimines of α-amino acids as coligands
Complexes of the general formula [Re-III(L)CI(PPh3)2] have been synthesised by reacting H2L and [ReOCl3(PPh3)(2)] in ethanol. Here H2L represents imines of alpha-amino acids (glycine, L-alanine, L-valine, L-phenylalanine) derived from salicylaldehyde and naphthaldehyde. The crystal structure of one complex has been determined. The complexes are monomiclear, paramagnetic and display paramagnetic H-1 NMR in CDCl3 solution. Their spectral and redox properties are scrutinised. (c) 2007 Elsevier Ltd. All rights reserved.