Ion-pair states of the ClO radical observed by multiphoton ionisation spectroscopy

被引：15

作者：

Cooper, MJ ^{[1
]}

DiezRojo, T ^{[1
]}

Rogers, LJ ^{[1
]}

Western, CM ^{[1
]}

Ashfold, MNR ^{[1
]}

Hudgens, JW ^{[1
]}

机构：

[1] NIST,CHEM & PHYS PROPERTIES DIV,GAITHERSBURG,MD 20899

来源：

CHEMICAL PHYSICS LETTERS | 1997年 / 272卷 / 3-4期

基金：

英国自然环境研究理事会; 英国工程与自然科学研究理事会;

关键词：

D O I：

10.1016/S0009-2614(97)88014-1

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

We present isotopically selected multiphoton ionisation spectra of the ClO radical following excitation in the wavelength range 276-261 nm, obtained using both a room-temperature sample and under the rotationally cold conditions in a pulsed molecular beam. In both cases high-resolution rotationally resolved spectra were obtained, with the 'cold' spectra showing discrete rovibrational bands. Analysis of the rotational structure leads to the identification of excited levels of ClO of (2) Pi symmetry resonant at the two-photon energy (72200-76200 cm(-1)). These we deduce to possess extended equilibrium bond lengths (R approximate to 2.4 Angstrom), and thus associate with One or more ion-pair states. Full interpretation of the observed spectra is complicated by the effects of additional wavelength-dependent intensity enhancements due to predissociated levels of the A(2) Pi state accidentally resonant at the energy of one absorbed photon. We report an isotopically resolved room-temperature 2 + 1 REMPI spectrum, involving a progression of vibrational levels of the previously documented C-2 Sigma(-) state of ClO. The observed C-X two-photon transitions are well reproduced using known spectroscopic constants. (C) 1997 Elsevier Science B.V.

引用

页码：232 / 238

页数：7

共 22 条

[1] MULTIPHOTON IONIZATION SPECTROSCOPY OF FREE-RADICAL SPECIES [J].