MATRIX-ISOLATION STUDY OF THE INTERACTION OF EXCITED NEON ATOMS WITH CCL4 - INFRARED-SPECTRA OF THE ION PRODUCTS AND OF CL2CCL-CENTER-DOT-CENTER-DOT-CL

When a Ne:CCl4 sample is codeposited at approximately 5 K with a beam of neon atoms that have been excited in a microwave discharge, the inf rared spectrum of the resulting deposit includes prominent absorptions not only of CCl3 but also of several other neutral and ionic species. The absorptions assigned to CCl3+, CCl2+, and CCl+ are consistent wit h previous spectroscopic identifications of these species. As at lower energies, the Cl4CCl .. Cl isomer of CCl4 contributes to the product spectrum. Higher level ab initio calculations of the fundamental vibra tions of this isomer and of its carbon-13 substituted counterpart give improved agreement with the experimentally observed infrared spectrum and, together with the results of a supplementary experiment, provide further support for the assignment of a structured absorption near 50 0 cm(-1) to this species, rather than to Cl-3(+). Uncharged Cl2CCl .. Cl is readily destroyed by visible radiation, with concomitant growth in the absorptions of CCl4. Photodestruction of ionic species occurs i n the ultraviolet spectral region. Evidence is presented for the stabi lization of Cl2CCl .. Cl- and of Cl3CCl- in these experiments. The lat ter species undergoes photodestruction in the near infrared spectral r egion. Two absorptions are tentatively assigned to the ClCCl .. Cl- fr agment ion. [S0021-9606(98)00841-1]. [S0021-9606(98)00841-1].