Photoaction in the course of chelate formation III. Ligand spin-reversal enhancements by heavy-metal ions and their influences on the excited-state 3(borobenzoylacetonide) complex formation

Abstract

The 1/1 “borobenzoylacetonide” chelate formation, in 8% (V/V) H 2SO 4/EtOEt solvent, has been investigated in the presence of Ag +, Cd 2+, Hg 2+, Tl+, under continuous ligand excitation at its ICT band. It is shown that the above metal ions (M n+) affect both ground-state and excited-state (T 1) interactions of benzoylacetone (BZA) with boron species. Ground-state influences are found to be attributable to BZA EDA complexes with M n+ formed most probably by the two-way actions: π 2(benzenering) or π to s A.O. (Ag +, Cd 2+, Hg 2+) and to 6 pA.O. (Tl +) and dπ y A.O. to π 2(benzenering * electron donation. T ↔ S crossings of the BZA's conjugate chelate from are found to be enhanced by all the above metal ions. Influences of these enhancements, on the 3BZA interaction with boron species, are quantitatively analysed.