Cadmium Coordination Complexes Research Articles

Carboxylate-Assisted Assembly of Zinc and Cadmium Coordination Complexes of 1,3,5-Tri-4-pyridyl-1,2-ethenylbenzene: Structures and Visible-Light-Induced Photocatalytic Degradation of Congo Red in Water

Solvothermal reactions of zinc and cadmium nitrates with 1,3,5-tri-4-pyridyl-1,2-ethenylbenzene (tpeb) in the presence of various carboxylic acids including 4-iodobenzoic acid (4-HIBA), benzene-1,4-dicarboxylic acid (1,4-H2BDC), 2,5-furandicarboxylic acid (2,5-H2FDC), 2,5-dibromoterephthalic acid (2,5-H2DBTPA), 1,2-cyclohexanedicarboxylic acid (1,2-H2CHDC), and 1,5-pentanedioic acid (1,5-H2PDC) gave rise to eight coordination complexes, viz, [Zn(tpeb)2(4-IBA)2]·2H2O (1), {[Cd(NO3)(tpeb)(4-IBA)]·H2O}n (2), {[Cd2(NO3)2(tpeb)2(1,4-BDC)]}n (3), {[Cd2(tpeb)2(2,5-FDC)2]·2H2O}n (4), [Cd(tpeb)(2,5-DBTPA)2]n (5), {[Cd2(H2O)2(tpeb)2(1,2-CHDC)2]·H2O}n (6), [Zn(tpeb)(1,2-CHDC)]n (7), and {[Zn(tpeb)(1,5-PDC)]·H2O}n (8). Compound 1 is a discrete mononuclear complex with its Zn(II) center coordinated by two pairs of tpeb and 4-IBA ligands. Compound 2 has a 2D waterfall-like network constructed from bridging [Cd(NO3)(4-IBA)] units with tpeb ligands. Compounds 3, 4, and 5 contain similar 1D [Cd(tpeb)]n chains, which are l...

Crystal structures, in situ synthesis in aqua conditions and luminescent properties of benzimidazole ligands and cadmium coordination complexes

Three cadmium complexes, [Cd(L2)2(H2O)4]·H2O (1), [Cd(L2)2(H2O)4]·8H2O (2), [Cd2(L3)2(SO4)(4,4′-bpy)0.5(H2O)3]·2.5H2O (3) have been obtained from L1 ligand and auxiliary ligand in hydrothermal conditions. The crystal structures reveal that L2·H2O can be transformed from L1 directly in hot water conditions, while L3 emerge in coordination complex via in situ reactions of L1 ligand. Complexes 1 and 2 are zero dimensional coordination complexes and there are interesting T12(4) water tapes exist in complex 2. 3 is three dimensional supramolecular structure which is comprised of interpenetrated one dimensional chains. The luminescent properties have been measured and show that the emission peaks are similar between L2·H2O and complex 1, but take place bathochromic shift for complex 2 which should be tentatively relative to conjugation of organic ligands and metal coordination reaction.

In vitro Antimicrobial Screening of Three Cadmium Coordination Complexes and Two Addition Compounds of Antimony and Arsenic

In vitro Antimicrobial Screening of Three Cadmium Coordination Complexes and Two Addition Compounds of Antimony and Arsenic

Ab initio study of Cd–thiol complexes: application to the modelling of the metallothionein active site

The metallothionein active site in vacuo was studied using ab initio methods as a necessary step in order to understand the relationship between the structure and the efficiency of the protein in binding cadmium ions. The natural Cd4Cys11 cluster located in the protein α-domain was represented by cadmium–thiolate complexes. First, it was shown, by comparison with available experimental results, that the geometry and the binding energy of cadmium coordination complexes can be correctly predicted at the RHF-MP2 theory level using the effective core potentials (ECP) and the double-ζ basis sets of Hay–Wadt, improved with polarization and diffuse functions. The computed geometry of the model system of the α-domain active site was then compared with that extracted from the X-ray crystal structure of the metallothionein. The significant difference between the two structures was attributed to the external constraints imposed in the natural cluster by the surrounding protein structure. The nature of the Cd–thiolate bond was further examined by calculating natural atomic populations and localizing the molecular orbitals. A good correlation between the Cd–S bond length and the amount of charge transferred from the ligand to the cadmium ion was found allowing an explanation of the effects of ligand protonation on the structure of mixed cadmium–thiol/thiolate complexes.