Matrix reactions of molecular oxygen with indium and gallium atoms

Abstract

Frozen inert gas matrices of N2 and Ar containing 02 and In or Ga atoms have been prepared by matrix isolation techniques and studied by infrared absorption spectroscopy. Analyses of the spectra have shown that these reagents react to produce metal superoxide molecules, M+02", which are similar to those of the alkali and alkaline earth metals. The stretching modes of these species absorb in the regions of 1080-1090 cm"1 for r1(A1), 330-380 cm"1 for * 2( ), and 270-290 cm"1 for ^(Bj). In addition to the superoxides, various aggregate species are produced. One of these has been identified as the superoxide dimer, which apparently has an 02M-M02 structure of I)2d symmetry. Another aggregate has been identified as a rhombic M02M species which is formed by the addition of a metal atom to the superoxide. Small quantities of the suboxide dimer (ln20)2 also were detected in these matrices. The evidence indicates that this species was formed by the addition of an In atom to each oxygen of the In02In(D2ft) species. This dimer is of interest because it is readily formed by aggregation of the suboxide monomer in experiments involving the vaporization of the condensed oxide systems.

On the Oxidation of Gallium and Indium: Characterization of the Cyclic and Linear GaO2 and InO2 Molecules Generated by the Spontaneous and Photoinduced Reaction of Ga and In Atoms with O2 and Determination of the Reaction Mechanism

“…In previous work, bands due to 1 a/1 b have already been assigned to the cyclic MO 2 molecules [2,3] and one band due to 2 a/2 b to linear OMO molecules.…”

“…[1] The reactions of Ga and In atoms with O 2 have already been studied with the aid of the matrix-isolation technique. 2 molecules photoisomerize to give the linear OMO molecules. The collected vibrational data were then used to characterize the bond properties of the linear OMO molecules in detail.…”

“…The collected vibrational data were then used to characterize the bond properties of the linear OMO molecules in detail. The results are compared to those obtained for CO 2 + and neutral OEO compounds, where E is an element of Group 14. Quantum-chemical calculations were carried out at various levels of theory for GaO 2 .…”

“…[2] They identified the cyclic, C 2v -symmetric MO 2 superoxo complexes as products of these reactions. A few years later (1982), Serebrennikov et al confirmed these results.…”

“…Thus, the linear molecule is not fully characterized in experiments or in calculations. Calculations on the reaction mechanism leading to cyclic or linear GaO 2 have also not been carried out so far.…”