Rotationally resolved nfrared spectrumof the Cl~--H_2 anion complex

摘要

The mid-infrared spectrum of the 37CI--Hz anion complex has been measured over the 3990-4051 cm -1 range (H- H stretch region) using infrared vibrational predissociation spectroscopy. Th spectrum features a well resolved I-I transition red shifted by 156 cm-l from the free Hz molecul stretch. Analysis of the P and R branch line positions using a linear molecule energy levt expression yields vo=4004.77:!:0.08 cm-l, B"=0.853:!: 0.002 cm-l, D"= (9.3:!: 1.0)X 10- cm-l, B' =0.919:!:0.002 cm-l, and D' =(9.0:!: 1.0)X 10-5 cm-l. The CI--Hz complex appear to have a linear equilibrium structure, with a vibrationally averaged separation of 3.19 A betwee the Cl- and the Hz center-of-mass. Vibrational excitation of the H-H stretch induces 0.12 A contraction in the intermolecular bond.