OPTICAL OPTICAL DOUBLE-RESONANCE SPECTROSCOPY OF CL2 - ANALYSIS OF THE 1G(3P2)-ALPHA-3-PI(1U) SYSTEM

The 1g(3P2)-A3Π(1u) transition is analyzed by optical-optical double resonance using the 1g(3P2)-A3Π(1u)-X1Σg+ photo-excitation sequence. The 1g(3P2) state is found to lie between the 2g and 0g+ ion-pair states tending toward Cl-(1S) + Cl+(3P2). A set of Dunham molecular parameters of the 1g(3P2) state derived from a global least-squares fit analysis of 526 transitions in the v′ = 0 ∼ 20 and J′ = 5 ∼ 52 ranges consists of Y00 = 57 572.209(5), Y10 = 252.2462(17), Y20 = -1.019 45(19), Y30 = 2.3740(60) × 10-3, Y01 = 0.116 622 5(54), Y11 = -6.4345(88) × 10-4, Y21 = 8.10(46) × 10-7, and Y02 = -9.96(19) × 10-8 (all in cm-1 and σ in parentheses). The Ω-type doubling constant of the 1g(3P2) state, q = B(f)-B(e) = 2.298(16) × 10-4, is discussed in view of the heterogeneous perturbation by surrounding ion-pair states. © 1991.