SPECTROSCOPIC DETECTION AND REACTIVITY OF THE CHLORINE ATOM CARBON-DISULFIDE MOLECULAR-COMPLEX

Pulse radiolysis and laser flash photolysis techniques have been used to generate and kinetically characterize the chlorine atom-carbon disulfide molecular complex (Cl./CS2) in CCl4 solution. The transient absorption spectrum of Cl./CS2 has been generated from three independent Cl. sources: pulse radiolysis of CCl4, 266-nm photodecomposition of CCl4, and photodissociation of Cl2. An absolute rate constant of 1.7 X 10(10) M-1 s-1 for the reaction of Cl. + CS2 was obtained from both the direct measurement of the decay of the charge-transfer band of Cl. in CCl4 (lambda(max) = 330 nm) and from the formation kinetics of Cl./CS2 (lambda(max) = 370 nm; shoulder = 490 nm). The properties of Cl./CS2 are compared with those of the molecular complexes of Cl. with benzene and pyridine. The reactivity observed monitoring the Cl./CS2 absorption band toward 2,3-dimethylbutane has also been investigated to determine the equilibrium constant (K) of the Cl./CS2 complex, and the value of K is compared to that determined by direct spectroscopic method. K for the Cl./pyridine complex has also been reevaluated.