The nitrite ® nitro isomerization in nitritopentaamine cobalt (III) halides has been known. In this paper, the effect of the size of the counter ions (noncoordinated groups) on the rate of isomerization in nitritopentaamine cobalt (III) halides, is reported. The rate of isomerization is decreased by increasing the size of the counter ions. This decrease is explained on the...

lanthanide(iii) chloro complexes of 4[n-(4’-hydroxy-3’-methoxybenzalidene) amino] antipyrine semicarbazone (hmbaaps) (i) and 4[n-(3’,4’,5’-trimethoxybenzalidene) amino] antipyrine semicarbazone (tmbaaps) (ii) with the general composition lncl3.2l (ln = la, pr, nd, sm, gd, tb, dy or ho; l = hmbaaps or tmbaaps) are reported. all the complexes were synthesized in ethanolic medium and refluxed the ...

Zinc finger domains are structures that mediate sequence recognition for a large number of DNA-binding proteins. These domains consist of sequences of amino acids containing cysteine and histidine residues tetrahedrally coordinated to a zinc ion. In this report, we present a means to selectively inhibit a zinc finger transcription factor with cobalt(III) Schiff-base complexes. 1H NMR spectrosco...

The cobalt(III) complexes of 4,11-diacetato-1,4,8,11-tetraazabicyclo[6.6.2]hexadecane (1), [Co(1)]PF6, and 4,11-diacetamido1,4,8,11-tetraazabicyclo[6.6.2]hexadecane (2), [Co(2)][PF6]3, have been synthesized and characterized. The crystal structure of [Co(1)]PF6 consists of an octahedral cobalt(III) cation coordinated to all four ligand nitrogen donors in the macrobicycle s cavity, as well as to...

The coordination chemistries of the tetradentate N2O2-type ligands N-(2-pyridylmethyl)iminodiethanol (H2pmide) and N-(2-pyridylmethyl)iminodiisopropanol (H2pmidip) have been investigated with nickel(ii) and cobalt(ii/iii) ions. Three novel complexes prepared and characterized are [(Hpmide)2Ni3(CH3COO)4] (1), [(Hpmide)2Co3(CH3COO)4] (2), and [(pmidip)2Co3(CH3COO)4] (3). In 1 and 2, two terminal ...

In an effort to develop new tripodal N-heterocyclic carbene (NHC) ligands for small molecule activation, two new classes of tripodal NHC ligands TIME and TIMEN have been synthesized. The carbon-anchored tris(carbene) ligand system TIME (R = Me, t-Bu) forms bior polynuclear metal complexes. While the methyl derivative exclusively forms trinuclear 3:2 complexes [(TIME)2M3] 3+ with group 11 metal ...