SURFACE-REACTION OF ORGANIC MATERIALS BY LASER-ABLATION OF MATRIX-ISOLATED PHOTOREACTIVE AROMATIC AZIDO COMPOUND

The ablation of pentafluorophenylazide (FPA), which was isolated in a chemically inert C6F14 solid matrix at 85 K, was carried out by irradi ation with a KrF excimer laser in vacuum. A large amount of pentafluor ophenylnitrene (FPN) was ejected explosively as fragments from the mat rix during irradiation. The photolysis of FPA was followed by mass spe ctrometry, UV-visible absorption spectroscopy and optical emission spe ctroscopy. It was found that the fragment beam of photolysed FPA was u seful for the surface chemical modification of organic materials, such as a poly(ethylene terephthalate) film and alkylthiol monolayer. Surf ace analyses of these materials by X-ray photoelectron spectroscopy an d Fourier transform IR reflection absorption spectroscopy indicated th at FPN was immobilized on the surface through chemical bonding. The mo dified surface showed hydrophobic properties due to a decrease in surf ace polarity by the deposition of the fluorinated group of FPN. (C) 19 97 Elsevier Science S.A.