MATRIX REACTIONS OF MOLECULAR-OXYGEN WITH INDIUM AND GALLIUM ATOMS

Frozen inert gas matrices of N2 and Ar containing O2 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+O2-, 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 v1(A1), 330-380 cm-1 for v2(A1), and 270-290 cm-1 for v3(B1). In addition to the superoxides, various aggregate species are produced. One of these has been identified as the superoxide dimer, which apparently has an O2M-MO2 structure of D2d symmetry. Another aggregate has been identified as a rhombic MO2M species which is formed by the addition of a metal atom to the superoxide. Small quantities of the suboxide dimer (In2O)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 InO2In(D2h) 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. © 1979 American Chemical Society.