First observations of laser-excited Hg3 and Hg2RG spectra in a supersonic expansion beam

Triatomic van der Waals complexes of mercury have been observed in a supersonic expansion beam crossed with a laser beam to produce excitation and fluorescence spectra. The expansion beam consisting of mercury and a (noble) carrier gas (RG) was excited in three separate spectral regions: in the vicinity of the Hg 2537 Angstrom intercombination line, near the (forbidden) Hg 6(3)P(2) <-- 6(1)S(0) atomic transition (2200-2290 Angstrom), and in the region of the Hg-2 GO(u)(+) <-- XOg+ transition (1975-2080 Angstrom). The resulting spectra, which were recorded in the spectral range 1900-6000 Angstrom, contained, in addition to the known Hg, Hg-2, and HgRG components, new absorption and fluorescence bands that are ascribed to Hg(2)RG and Hg, complexes. (C) 1998 Academic Press.