STABILITY OF MERCAPTO-4-(2-THIENYL)-3-BUTENE-2-ONE-NITROGENEOUS BASE TERNARY COMPLEX ON THE BASIS OF HSAB PRINCIPLE

Synergistic extraction constants for apto-4-(2-thienyl)-3-butene-2-one =HR)-nitrogeneous base(2,2'-bipyridine=bpy, 1,10-phenanthroline=phen) system were expressed by the HSAB parameters proposed previously. Stab ilities of the synergistic adducts, ZnR2(bpy), ZnR2(phen), CdR2(bpy) a nd CdR2(phen), were also discussed by assuming the additive property o f these parameters. The estimated stabilities were examined by H-1 NMR and IR measurements. The metal(II)-STTA bond was weakened by the coor dination of additives. The formation of a ternary complex was consider ed to proceed through the reaction between a cationic complex and a ch elate anion in the synergistic extraction system when a neutral bident ate nitrogeneous base such as phen or bpy was used.