Spectrophotometric Study of the Charge Transfer Complex of 2,2-Dichloro-5,6-dicyano-1,4-benzoquinone and 1,4,8,11-Tetraazacyclotetradecane in Chloroform Solution

Abstract

A spectrophotometric study concerning the charge transfer reaction of 1,4,8,11-tetraazacyclotetradecane (CYCLAM) and p-acceptor, 2,2-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) has been performed in chloroform solution at 25 °C. The results are indicative of the formation of CYCLAM-DDQ and CYCLAM⁺-DDQ^– through equilibrium and non-equilibrium steps, respectively. The formation constant of the equilibrium step has been evaluated by the computer fitting of absorbance-mole ratio data as log K_f = 5.5 ± 0.2. The plotting ln (a_t/A₀) vs. time has obtained the rate constant of non-equilibrium step. The obtained k value is equal to 0.011 ± 0.001 min^–1. Solid complex of CYCLAM-DDQ has been isolated and the IR spectrum of the complex has been compared with the spectra of donor and acceptor.