DETERMINATION OF THE BINDING CONSTANTS, BOUND CHEMICAL SHIFTS, AND STOICHIOMETRY OF LANTHANIDE-SUBSTRATE COMPLEXES

Analysis of the experimental results of the equilibrium between a lanthanide shift reagent, L, and a substrate, S, is presented. When different methods were used, evaluation of equilibrium binding constants (KB), bound chemical shift (DB), and stoichiometry (n) of lanthanide (L)-substrate (S) complexes brought about the same numerical values under the conditions of [S]o> [L]o. Finally, it is shown that the association between the lanthanide and the substrate (i.e. 1-(X-benzo [b] thienyl-ethylacetate derivatives) has 1:1 stoichiometry.

IBRAHIM M AL-NAJJAR ,SALIM S AL-SHOWIMAN ,HASSAN B AMIN ,