Open AccessEnd‐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
Author(s) -
Das Kuheli,
Datta Amitabha,
Sinha Chittaranjan,
Huang JuiHsien,
Garribba Eugenio,
Hsiao ChingSheng,
Hsu ChinLin
Publication year - 2012
Publication title -
chemistryopen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 29
ISSN - 2191-1363
DOI - 10.1002/open.201100011
Subject(s) - chemistry , hydrazone , thiocyanate , electron paramagnetic resonance , crystallography , ligand (biochemistry) , deprotonation , copper , magnetic susceptibility , coordination polymer , stereochemistry , coordination complex , carboxylate , crystal structure , metal , inorganic chemistry , ion , nuclear magnetic resonance , organic chemistry , biochemistry , physics , receptor
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 CuCl 2 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 [Cu 2 L 2 Cl 2 ] ( 2 ) (where L=CH 3 C(O)=NN=CCH 3 C 5 H 4 N). 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.