Structural Study on the Complex of Ortho-Ester Tetra Azophenylcalix[4]arene (TEAC) with Th(IV)

Abstract

A new 1:1 complex between Ortho-Ester Tetra-Azophenylcalix[4]arene (TEAC) and Thorium(IV) was found in weakly acidic medium (pH =4-5), ?max = 520 nm, Beer’s law was obeyed in the range 2.5 ×10-6 – 2.5×10-5 mol.L-1 of Th(IV), the limit of detection was 1.0 × 10? 6 mol.L-1 and linear regression equation was determined to be: absorbance (A) = 0,248×C(10-5 mol.L-1) + 0,02 (R2 = 0,990, n =7). The FT-IR, HNMR, Raman spectroscopies were also used to provide the existence of this complex, and the Molecular Mechanics (MM) method in Arguslab software was applied to optimize the structure. The energy of the system, QEq charge, bond lengths and bond angles were also calculated by this program. Combining all data, the structure of complex TEAC - Th(IV) has been proposed.