Electrochemiluminescence on np(1)-metals 1. The analysis of chemiluminescent reactions

The phenomenon of electrochemiluminescence (ecl) during cathodic polarizati on of the np(1)-metals (AI, Ga and In) in peroxydisulfate solutions under d ifferent Values of pH is studied. It is proposed that the source of the lig ht emission is a radiative deactivation of the singlet dioxygen, which is g enerated in the electrochemical system. A quantum-mechanical simulation of the free radical recombination reaction, during which the singlet dioxygen is generated, was carried out. It was determined that the HO2.- (OH)-O-.-re combination may proceed, under certain conditions, without a potential barr ier, while the minimum potential barrier for the SO4.- - (O2H)-O-.-recombin ation (equals 27.1 kJ mol(-1)) is observed at an angle of attack 100 degree s. (C) 1999 Elsevier Science Ltd. All rights reserved.