Ultraviolet photoelectron spectroscopy of the chromium dioxide negative ion

Abstract

The 351 nm photoelectron spectrum of chromium dioxide negative ion has been measured. Two vibrational frequencies of neutral chromium dioxide are observed in the spectrum, at 220±20 and 895±20 cm−1, and are assigned to the bending mode and symmetric stretch, respectively. From hot bands in the spectrum, a frequency of 205±40 cm−1 is determined for the bending mode in the negative ion. The electron affinity of CrO2 is found to be 2.413±0.008 eV. The measured anisotropy parameter for photodetachment indicates that the electron is detached from an orbital with significant 4s character.

A Critical Appraisal of the Experimental Data on the Molecular Structure and Spectra of Halides, Oxides, and Hydrides of the s-, d-, and f-Block Elements

“…An alternative approach to obtain information on the energy levels of the neutral molecule [82,83] is to use negative ion photoelectron spectroscopy (NIPES). The resolution is not high, so no information on bond angles is available (for example, for CrO 2 n Ä 1 895 AE 20, n Ä 2 220 AE 20 cm À1 ).…”

Franck-Condon simulation of the anion photoelectron spectroscopy of CrO2 by coherent state method

“…In Wenthold's NIPES study for CrO 2 [10], the vibrational transition assignments of some peaks were not given. Inspired by perfecting the vibrational transition assignments for the anion [10] photoelectron spectroscopy reported by Wenthold, in this paper, high level DFT and ab initio calculations were performed on CrO 2 (X 3 B 1 ) and CrO 2 -(X 4 B 1 ), and a program was developed to calculate multidimensional Franck-Condon factors.…”

“…Wenthold et al [10] deduced a value of 205 ± 40 cm −1 for the bending frequency by means of NIPES. The only report on the OCr-O bond angle of CrO 2 -(X 4 B 1 ) was given by Zhou and Andrews [9], estimating a value of 140 ± 5 • .…”

“…According to these studies, the values of the symmetric stretching frequency of CrO 2 range from 895 to 960.1 cm −1 , and those of the antisymmetric stretching frequency range from 964 to 974.9 cm −1 , with most around 970 cm −1 . The bending frequency of CrO 2 has been measured by Wenthold et al [10] using negative ion photoelectron spectroscopy(NIPES), predicting a value of 220 ± 20 cm −1 . Moreover, a value of 220 ± 40 cm −1 for the bending frequency of CrO 2 was given by Gutsev and co-workers [11] by virtue of NIPES.…”

“…Chromium dioxide is widely used in magnetic recording tapes and other magnetic layers, and therefore its properties in bulk phase have been well known [1,2], meanwhile a number of studies [3][4][5][6][7][8][9][10][11] have focused on the isolated CrO 2 molecule at the X 3 B 1 ground state with the purpose of determining the vibrational frequencies and the O-Cr-O bond angle. These studies are summarized in Table 1.…”