INFRARED-SPECTRA OF VAPORIZED PT AND PT-2 IN RARE-GAS MATRICES - UNIQUE PHONON EFFECTS(H)

Laser-vaporized platinum metal, trapped in solid Ne, Ar, Kr, Xe (and A r, Kr mixture) produced a progression of absorption bands with a spaci ng of similar to 200 cm(-1) beginning at 1942 cm(-1) in Ne and shiftin g successively to 1579 cm(-1) in Xe. In contrast with the specimen in Ne, strong patterns of similar sidebands appeared in the spectra in th e heavier matrices. This matrix effect is considered in some detail in attempting to assign the trapped molecule and to explain the source a nd structure of the sidebands. The conclusion is that the absorption s pectrum is the previously unobserved (3) Pi(u)(1(u))<--X (3) Sigma(g)( -)(0(g)(+)) transition of Pt-2 (inferred from Balasubramanian's calcul ation) but with unique phonon interactions in the heavier matrices. Wh en hydrogen was present in the matrix gases, Pt hydride bands were obs erved but not prominently, in contrast to Ni+H-2 matrices. (C) 1997 Am erican Institute of Physics.