Solid films composed principally of carbon and nitrogen were grown on a variety of substrates at ambient temperature in a flow-tube reactor by upstream mixing of cyanogen azide, cyanogen, or cyanogen halides with active nitrogen obtained from an electrical discharge. Ab initio calculations and dependence of deposition rates on both choice of donor and N atom production suggests that NCN radicals are a critical growth species. The films obtained are electrically insulating with a refractive index of 2.3 at visible wavelength and are optically transparent from 550 nm out to at least 14 µm with the exception of two broad absorption bands centered at 1550 and 3250 cm -1 , the latter band growing in upon exposure of the film to atmospheric moisture. Film analysis by X-ray photoelectron spectroscopy revealed comparable concentrations of both carbon-tonitrogen bonds (with approximate C 3 N 4 stoichiometry) and diamond-like carbon-to-carbon bonds as well as minority bonding of carbon to impurities.

EtOH and MTHF solutions containing Cu + ions are γ-irradiated at 77 K. ESR spectra are attributed, for the first time, to Cu 0 that is produced radiation-chemically by reducing Cu + ions in the solutions at 77 K. A large delocalization of the unpaired spin density of Cu 0 onto ligands is deduced. No evidence for formation of the dimer cation of Cu 0 has been obtained. This is contrary to the case of Ag 0 produced in the solutions containing Ag + ions. The NUV absorption spectrum of Cu 0 is decomposed into five Gaussian bands that are attributed to two types of exciplexes formed between excited Cu 0 and ligands: one associates with Cu + ions as well as solvent molecules, the other consists mainly of solvent molecules. The exciplexes are supposed to be transferred to relaxed states followed by two emission bands, one of which is common to both solvents and the other is characteristic of the solvents. The absorption band at 255 nm is ascribed to a photoionization spectrum of Cu 0 .