KONFORMASI KOMPLEKS [Zn2+.Bz12C4] TERSUBSTITUSI DALAM SISTEM MIKROSOLVASI BERDASARKAN METODE MP2

Selectivity of benzo�12�crown�4 (Bz12C4) to bind a Zn2+ cation was analyzed based on computational chemistry calculations using Post�SCF/MP2 method using LanL2MB as a basis set. The substituent effects of �CH=CH2, �OH, �COOH, and �Br on Bz12C4, interaction between substituted Bz12C4 with Zn2+ cation, and interaction between [Zn2+. Bz12C4] complexes with water were evaluated using computational chemistry calculations. The structure of crown ether, crown ether�cation complex, and crown ether�cation complexes in the microsolvation system has been optimized. Interaction of the crown ether�cation and microsolvation system was discussed in term of the structure parameter of crown ether, atomic charges, and energy interaction. Selectivity of the crown ether to bind cation depends on the compatibility of the diameter cation of cation and cavity of crown ether. Any substituent on the benzene in crown ether which supports the symmetrical form of the crown ethermetal cation complexes would increase the selectivity of the crown ether to bind the cation. The electron donating groups would increase the capability of crown ether to bind cation by means of induction effect, while electron withdrawing groups reduce the ability of crown ether to bind cation. There was just one addition of water molecule that can be used to modeling in the microsolvation system. The MP2 method gave [Zn2+.Bz12C4] complexes unplanar conformation between Zn2+ and the oxygens on the 12C4