Журнал структурной химии №5 2011 (671,00 руб.)

P. 449. 905 2011. 52, 5 . 906 916 UDC 541.6:546.56:541.49 MODELING OF THE BIS(GLYCINATO)COPPER(II) CISTRANS ISOMERIZATION PROCESS: THEORETICAL ANALYSIS 2011 V. Gomzi* Division of Organic Chemistry and Biochemistry, Quantum Organic Chemistry Group, Ruer Bokovi Institute, Zagreb, Croatia Received August, 5, 2010 In a number of theoretical works, the cistrans isomerization of bis(glycinato)copper(II) and its interaction with water molecules is investigated. <...> The interactions with the water medium modeled either by adding water molecules explicitly or through the Polarized Continuum Model (PCM) are investigated by the density functional (B3LYP) method in order to question the reliability of theoretical results. <...> The crucial dependence of theoretical energies on the accuracy of PCM corrections is established. <...> It is shown that for bis(glycinato)copper(II) the differences of isomer energies are of the order of the upper limit of the reliability of PCM corrections. <...> Based on the calculation results, two possible mechanisms for the cistrans isomerization are proposed. <...> It is shown that only the inclusion of two explicit water molecules enables the modeling of the isomerization mechanism involving the interchange of glycine and water oxygen atoms in copper coordination. <...> Blue copper proteins, plastocyanin, or cytochrome-c oxidase are just few examples of such, in which a copper atom is the reactive transition metal center [ 5 ]. <...> In the investigations of model systems, it has been shown that copper(II) radical species can arise in the structures formed by a copper atom interacting with the DNA or proteins. <...> Part of the problem may be attributed to the fact that the calculation methods (density functional, basis set, or the force field) still have not been optimized to describe all the complexities of the copper atom interactions [ 17, 18 ]. <...> By a comparison of the results of DFT theoretical calculations with the available experimental data and similar investigations of the gas-phase Cu(Gly)2 complex and the same complex in water solution performed previously [ 1921 ], the properties of the cistrans isomerization process have been further examined. <...> Rates of * E-mail: vgomzi@irb.hr MODELING BIS(GLYCINATO)COPPER(II) CISTRANS ISOMERIZATION PROCESS 907 conversion obtained from the DFT calculated energies of the two isomers and the transition state (TS) between these were estimated <...>