title: Study on synthesis, structure, and DNA-binding of lanthanide complexes with 2-carboxylbenzaldehyde thiosemicarbazone.
abstract: 2-Carboxylbenzaldehyde thiosemicarbazone (HL), and its three lanthanide (III) complexes, LnL(3) x 4H(2)O [Ln(III)=La, Sm, Eu], have been synthesized in water. The complexes were characterized by elemental analyses, molar conductivity and IR spectra. The crystal structure of [Sm(2)L(6)(CH(3)OH)(4)] x 7.5CH(3)OH x 0.5H(2)O obtained from methanol solution was determined by X-ray diffraction analysis, crystallized in the triclinic system, space group P-1, Z=1, a=12.217 (2)A, b=14.706 (2)A, c=15.035 (2)A, alpha=111.84(1) degrees , beta=103.47(1) degrees , gamma=104.24(1) degrees , R(1)=0.0290. It has symmetrical (mu-OCO)(2), (mu-O)(2) and disamarium(III) units. The coordination geometry of each Sm(III) ion is a distorted tetradecahedron with nine oxygen atoms. In addition, the DNA-binding properties of the ligand and its complexes have been investigated by absorption, fluorescence, and viscosity measurements. The experimental results indicate that the ligand and the Sm-complex can bind to DNA, but the other two complexes cannot; the binding affinity of the Sm-complex is higher than that of the ligand and the intrinsic binding constant K(b) of the complex is 3.22 x 10(5)M(-1).
authors.affiliation: College of Chemistry and Chemical Engineering and State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, PR China. yangzy@lzu.edu.cn
authors.forename: Zheng-Yin
authors.initials: ZY
authors.lastname: Yang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
mesh_terms: D001547:Benzaldehydes / Q000138:chemical synthesis* / Q000494:pharmacology*; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry*; D015195:Drug Design; D007700:Kinetics; D028581:Lanthanoid Series Elements / Q000737:chemistry* / Q000494:pharmacology; D008024:Ligands; D000432:Methanol / Q000737:chemistry; D008956:Models, Chemical; D008968:Molecular Conformation; D011485:Protein Binding; D013055:Spectrophotometry, Infrared; D013696:Temperature; D013882:Thiosemicarbazones / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology
chemical_list: C521291:2-carboxylbenzaldehyde thiosemicarbazone; D001547:Benzaldehydes; D028581:Lanthanoid Series Elements; D008024:Ligands; D013882:Thiosemicarbazones; D004247:DNA; D000432:Methanol