INFRARED-SPECTRUM AND STRUCTURE OF THE GACO3 RADICAL - A MATRIX-ISOLATION STUDY

The GaCO3 radical can be generated by in situ UV photolysis (4-5 eV) o f the GaCO2(CO2) van der Waals complex. Analyses of the isotopic shift s of the five observed fundamentals of the GaCO3 species in the (CO3)- C-13-O-16, (CO3)-C-12-O-18, (OCO2)-O-16-O-18, (OCOO)-O-16-O-18-O-16, ( OCOO)-O-18-O-16-O-18 isotopic forms show unambiguously that it must ha ve C2v symmetry. Normal coordinate analyses strongly suggest that the gallium atom is bound to two oxygen atoms in a bidentate fashion, and that the CO bonds are strongly unequivalent: two having typical single bond force constants (F(C-O) = 5.6 +/- 0.2 mdyn angstrom-1) and one a typical double bond value (F(C=O) = 11.9 +/- 0.2 mdyn angstrom-1).