OBSERVATION OF THE O-U(-) (P-3(1)) ION-PAIR STATE OF CL-2 BY PERTURBATION-FACILITATED OPTICAL-OPTICAL DOUBLE-RESONANCE

Perturbation-facilitated optical-optical double resonance spectroscopy was used to study the 0(u)(-)(P-3(1)) ion-pair state of Cl-2 correlat ing to Cl-(S-1) + Cl+(P-3(1)). The 0(u)(-)(P-3(1)) state was combined with the X(1) Sigma(g)(+) ground state in a (1 + 2) photoexcitation se quence through A(3) Pi(1(u)) similar to B'(3) Pi(0(u)(-)) mixed interm ediate levels. The spectra were analyzed by including the heterogeneou s interaction with a new 1(u)(P-3(1)) state, and the Dunham coefficien ts were derived for the 0(u)(-)(P-3(1)) state.