Rotationally resolved spectra of two van der Waals states of I + Cl

• Published in: Journal of molecular spectroscopy 1985, Vol.114 (1), p.219-227
• Main Authors: Brand, J.C.D, Hoy, A.R
• Format: Article
• Language: English
• Subjects: Atomic and molecular physics; Exact sciences and technology; Molecular properties and interactions with photons; Physics; Properties of molecules and molecular ions; Rotation, vibration and vibration-rotation constants
• ISSN: 0022-2852; 1096-083X
• DOI: 10.1016/0022-2852(85)90350-9

Three-step optical resonance is used to execute state-selected transitions from the ground state of ICl to two van der Waals states, b( Ω = 1) and b′( Ω = 2) , both of which correlate with the second dissociation limit, I( 2P 3 2 ) + Cl( 2P 1 2 ) , of ICl. Since the B(0 +) state also belongs to this limit, three out of five states converging to I + Cl ∗ are now accounted for. Principal constants of these states are: b′(2): T e = 18275.84, ω e = 31.093, ω e x e = 1.672, ω e y e = 0.0070, B e = 0.034834, α e = .001587, and D e = 164.09 cm −1; b(1): T e = 18273.30, ω e = 26.75, ω e x e = 0.882, B e = 0.03579, q = 0.00084, and D e = 166.63 cm −1. In both states the equilibrium distance is near 4.2 Å, slightly greater than the sum of van der Waals contact radii, r I + r Cl = 3.95 A ̊ . The large value of q in the b(1) state indicates that, in the basis set |j aj bj Ω〉 ( a = I, b = Cl, j = j a + j b ) the b(1) and b′(2) states belong to j = 1 and j = 2 “complexes,” respectively.