|$B1i!!Bj(B||Chemisorption of aromatic nitrogen heterocyclics over clay surface - a density functional study|
||O A. Chatterjee, T. Iwasaki and T. Ebina(Tohoku National Industrial Research Institute)|
$B")(B983-8551 Nigatake 4-2-1, Miyagino-ku Tohoku National Industrial Research Institute
TEL: 022-237-5211 FAX:022-236-6839
|$B%-!<%o!<%I(B||Chemisoprtion, Nitrogen hetrocyclics, Clay, DFT|
|DFT calculations were performed on clay cluster and aromatic nitrogen heterocyclics, viz. pyrrole, imidazole, pyridine and indole, in order to investigate the interaction and mechanism of chemisorption of biomacromolecules over clay.|
||O2 workstatuion||O S $BL>(B||UNIX||$B%=!<%98@8l(B||DMOL cide of MSI Inc.||$B<~JU5!4o(B|
The function f is the local quantity, which has different values at different points in the species, N is the total number of electrons, $B&L(B is the chemical potential, and v is the potential acting on an electron due to all nuclei present. The gross atomic charges were evaluated by using the technique of electrostatic potential (ESP) driven charges. The Al2Si6O24H18 cluster was generated from the clay structure as shown in Fig. 1(a). Now for the local softness calculations a smaller cluster with formula AlSi4O16H10 is chosen.
First from the Fukui function values the active site of the interacting molecule and clay clusters were monitored. This is followed by the interaction energy calculations to validate the results obtained from the reactivity indices. Both cation-$B&P(B and H-bond interactions were compared. Although the calculated binding strength is similar for both the interactions, but the enthalpy change of the whole reaction process suggested that the formation of H-bond complex is favorable to the stability of the whole system. The results also suggest that that all the H-atoms of the protonated heterocyclic are likely to be used as hydrogen bond donor.