UV laser photodeposition of nanomagnetic soot from gaseous benzene and acetonitrile–benzene mixture

Megawatt KrF laser gas-phase photolysis of benzene and acetonitrile–benzene mixture was studied by using mass spectroscopy–gas-chromatography and Fourier transform infrared spectroscopy for analyses of volatile products, and by Fourier transform infrared, Raman and X-ray photoelectron spectroscopy, electron microscopy and magnetization measurements for analyses of solid products deposited from the gas-phase. The results are consistent with carbonization of benzene and decomposition of non-absorbing acetonitrile in carbonizing benzene through collisions with excited benzene and/or its fragments. The solid products from benzene and acetonitrile–benzene mixture have large surface area and are characterized as nanomagnetic amorphous carbonaceous soot containing unsaturated C centers prone to oxidation. The nanosoot from acetonitrile–benzene mixture incorporates CN groups, confirms reactions of benzene fragments with CN radical and has a potential for modification by reactions at the CN bonds.

► Megawatt KrF laser gas-phase photolysis of benzene in absence and presence of non-absorbing acetonitrile.
► Formation of volatile unsaturated hydrocarbons and CN-substituted hydrocarbons.
► Photodeposition of carbonaceous and CN-substituted carbonaceous soot.
► Amorphous soot with large surface area, C–H bonds and large fractions of sp2 carbons.
► Superficial oxidation of soot in atmosphere.
► Soot magnetic behaviour due to both paramagnetic and ferromagnetic contributions.