title: End-to-End Thiocyanato-Bridged Helical Chain Polymer and Dichlorido-Bridged Copper(II) Complexes with a Hydrazone Ligand: Synthesis, Characterisation by Electron Paramagnetic Resonance and Variable-Temperature Magnetic Studies, and Inhibitory Effects on Human Colorectal Carcinoma Cells.
abstract: The reactions of the tridentate hydrazone ligand, N'-[1-(pyridin-2-yl)ethylidene]acetohydrazide (HL), obtained by condensation of 2-acetylpyridine with acetic hyadrazide, with copper nitrate trihydrate in the presence of thiocyanate, or with CuCl2 produce two distinct coordination compounds, namely a one-dimensional helical coordination chain of [CuL(NCS)] n (1) units, and a doubly chlorido-bridged dinuclear complex [Cu2L2Cl2] (2) (where L=CH3C(O)=N-N=CCH3C5H4N). Single-crystal X-ray structural determination studies reveal that in complex 1, a deprotonated hydrazone ligand L(-) coordinates a copper(II) ion that is bridged to two neighbouring metal centres by SCN(-) anions, generating a one-dimensional helical coordination chain. In complex 2, two symmetry-related, adjacent copper(II) coordination entities are doubly chlorido-bridged, producing a dicopper entity with a Cu⋅⋅⋅Cu distance of 3.402 (1) Å. The two coordination compounds have been fully characterised by elemental analysis, spectroscopic techniques including IR, UV-vis and electron paramagnetic resonance, and variable-temperature magnetic studies. The biological effects of 1 and 2 on the viability of human colorectal carcinoma cells (COLO-205 and HT-29) were evaluated using an MTT assay, and the results indicate that these complexes induce a decrease in cell-population growth of human colorectal carcinoma cells with apoptosis.
authors.affiliation: Department of Chemistry, Jadavpur University 188 Raja S. C. Mallik Road, 700032 Kolkata (India).
authors.forename: Kuheli
authors.initials: K
authors.lastname: Das
authors.affiliation: Department of Chemistry, National Changhua University of Education 1 Jin-De Road, 50058 Changhua (Taiwan) E-mail: amitd_ju@yahoo.co.in juihuang@cc.ncue.edu.tw.
authors.forename: Amitabha
authors.initials: A
authors.lastname: Datta
authors.affiliation: Department of Chemistry, Jadavpur University 188 Raja S. C. Mallik Road, 700032 Kolkata (India).
authors.forename: Chittaranjan
authors.initials: C
authors.lastname: Sinha
authors.affiliation: Department of Chemistry, National Changhua University of Education 1 Jin-De Road, 50058 Changhua (Taiwan) E-mail: amitd_ju@yahoo.co.in juihuang@cc.ncue.edu.tw.
authors.forename: Jui-Hsien
authors.initials: JH
authors.lastname: Huang
authors.affiliation: Dipartimento di Chimica and Centro Interdisciplinare per lo Sviluppo della Ricerca Biotecnologica e per lo Studio della Biodiversità della Sardegna, Università degli Studi di Sassari Via Vienna 2, 07100 Sassari (Italy).
authors.forename: Eugenio
authors.initials: E
authors.lastname: Garribba
authors.affiliation: Department of Chemistry, National Changhua University of Education 1 Jin-De Road, 50058 Changhua (Taiwan) E-mail: amitd_ju@yahoo.co.in juihuang@cc.ncue.edu.tw.
authors.forename: Ching-Sheng
authors.initials: CS
authors.lastname: Hsiao
authors.affiliation: School of Nutrition, Chung Shan Medical University No. 110, Sec.1, Cheng-Kuo N. Rd., 40201 Taichung (Taiwan) Department of Nutrition, Chung Shan Medical University Hospital No. 110, Sec.1, Jianguo N. Rd., 40201 Taichung (Taiwan).
authors.forename: Chin-Lin
authors.initials: CL
authors.lastname: Hsu
keywords: copper(II) complexes; electron paramagnetic resonance spectroscopy; hydrazone ligands; variable-temperature magnetic studies