Effect of Mixed Solvent System on Intramolecular Interactions of Metal Mediated Ternary Complexes of Beta-Hydroxy Ketone Derivatives and Benzotriazole Derivatives in Solution.

Abstract

The stabilities of ternary complexes of metal ions (copper, nickel, zinc and cobalt) with beta-hydroxy ketone(BHK) derivatives and benzotriazole(BTAZ) derivatives in various mixed solvent systems (Water+Dioxane) medium in 0.1 M KNO3 ionic strength at 25 0 C using pH metric titration method have been established. The data reveal that the copper forms more stable complexes, which is followed by zinc and Ni complexes with these ligands. Cobalt form less stable complexes with these ligands. The stabilities of these complexes are further quantified with Δ log K values, intra-molecular equilibrium constants and percentage of stacking interaction in the ternary systems. The observed positive Δ log K values suggest that the flexible side chain alkyl moiety (ethyl group, butyl group) or aromatic moiety (phenyl group) in BHK ligand overlaps with the fixed aromatic moiety of BTAZ ligand in the ternary complex, which results in the …………………………………………………………………………………………………….... Introduction:-A metal ion interactions with various ligands is an extremely diversified field [1][2][3][4][5][6][7][8][9][10][11], because the interaction as well as the resulting complex can have different applications in the biological field [12][13][14][15][16][17][18][19][20][21], development of luminescent materials, color stabilizing agents for toners in color photography, catalysts, therapeutic advantage [22][23][24][25][26][27][28][29][30][31][32][33][34], in the electronic display devices [35][36][37][38][39][40][41][42][43][44][45][46][47] or fluorescent probes [48][49][50][51][52][53][54][55][56][57][58] and can also be used in the resin technology [59][60][61][62][63][64][65]. In all these cases, the utility of metal-ligand complex is directly related to the stability of the complex which is a tunable parameter.The ligand can be a biomolecule [66][67][68][69][70] or a complexing agent [71][72][73][74][75] or simply scientifically a designed compound [76][77][78][79][80]. Both the metal ion interactions with the ligands and the metal-ligand complexes have been