Aquation

About: Aquation is a research topic. Over the lifetime, 1443 publications have been published within this topic receiving 17507 citations.

Octahedral cobalt(III) complexes of the chloropentammine type. Part XIII. cis-Chloro-2-methoxyethylamine- and cis-chloro-3-methoxy-propylamine-bis(ethylenediamine)cobalt(III) complexes

Abstract: Salts of one isomer of the chloro-2-methoxyethylamine- and chloro-3-methoxypropylamine-bis(ethylenediamine)-cobalt(III) cations have been prepared and characterised. Based on visible and i.r. absorption spectra, these complexes are assigned a cis configuration, with the amino-ether ligands occupying one co-ordination through nitrogen. The first-order rate constants for the solvolytic aquation of these cations have been determined at different temperatures and the Arrhenius parameters calculated. These results have been discussed in terms of a unimolecular exchange between a water molecule in the solvation shell and the chloro-ligand in the co-ordination shell of the complex. The second-order rate constants for the base hydrolysis of these cations have also been determined at 0° and ionic strength of 0·1M. This reaction is believed to take place by an SN1/P mechanism.

Solvent effects on the aquation of chloropentammine-cobalt(III) perchlorate in ethanol-water

Abstract: The aquation kinetics of the chloropenta-aminecobalt(III) ion in H2O−EtOH mixtures have been determined. A new correlation is described for calculating the chemical potential from kinetic data and molar thermodynamic excess functions for binary mixtures. The rate constants correlate well with Grunwald-Winstein solvating power Y parameter and with the dielectric constant of the medium. The data supports the D mechanism.

Redox‐Active Cobalt Complexes as Promising Antitumor Agents.

Abstract: Cobalt(iii) complexes with tetradentate aliphatic Schiff"s bases containing also compounds of the vitamin PP series or their analogs as axial ligands were synthesized as potential antitumor agents. The behavior of these redox-active complexes in chemical processes that presumably govern their biological action was studied. These processes include aquation and subsequent decomposition, electrode and homogeneous redox reactions, and catalytic activity in autooxidation of biosubstrates, especially at the stages of generation and consumption of reactive oxygen species (ROS). The antitumor action of these complexes in vivo was studied. Changes in the organisms of laboratory animals characteristic of processes involving ROS were followed at the cellular and molecular levels. The tumor-selective action of the complexes is due to specific features of microenvironment of tumor cells. Some of them exhibit a strong antimetastatic effect, which exceeds that for a number of drugs used in clinical practice. A complex with nicotinamide was recommended for preclinical studies. The scope of application of the redox-active transition metal complexes in oncology is discussed.

Reactions of ruthenium(III) ammine complexes. I. Competing acid hydrolysis and redox reactions of pentaammineruthenium(III) ions

Abstract: A study of acid hydrolysis of acidopentaammines of ruthenium(III) shows that aquation is not the only reaction taking place. For the halopentaammines, both in the presence and absence of light, reduction occurs with the formation of ruthenium(II) and free halogen. When azide, instead of halide ion, is coordinated to the metal, ruthenium(II) nitrogen complexes can be prepared. The solid state decomposition of [Ru(trien)(N3)2]+ ion to [Ru(trien)N3N2]+ is described.