Carbon microsphere-supported Cu nanoparticles were fabricated, characterized, and applied for synthesis.

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The [NH, C, N, O] and the [NH, C, N, S] molecular systems were investigated by computational and matrix-isolation spectroscopic methods. The determination of the equilibrium structures and relative energies by CCSD(T) method was followed by the computation of the harmonic and anharmonic vibrational wavenumbers, infrared intensities, relative Raman activities, and UV excitation energies. These computed data were used to assist the identification of products obtained by UV laser photolysis of 3,4-diaminofurazan and 3,4-diaminothiadiazole in low-temperature Ar and Kr matrices. It is shown that two open-chain HNNCX and HNCNX and one cyclic HNC(NX) (X = O, S) isomers are generated in the case of both systems. Except for HNNCO and HNCNS, the present study reports the first generation and spectroscopic identification of these compounds.

The [NH 2 , C, N, O] and the [NH 2 , C, N, S] systems were investigated by quantum-chemical computations and matrixisolation spectroscopic methods. The equilibrium structures of the isomers and their relative energies were determined by CCSD(T) method. This was followed by the computation of the harmonic and anharmonic vibrational wavenumbers, infrared intensities, relative Raman activities and UV excitation energies. These computed data were used to assist the identification of products obtained by UV laser photolysis of 3,4-diaminofurazan, 3,4-diaminothiadiazole and 1,2,4thiadiazole-3,5-diamine in low-temperature Ar and Kr matrices. a Experimentally, first the precursors were studied by matrix-isolation IR and UV spectroscopic methods. Based on these UV spectra, different wavelengths were selected for photolysis. The irradiations, carried out by a tunable UV laser-light source, resulted in the decomposition of the precursors, and in the appearance of new bands in the IR spectra. Some of these bands were assigned to cyanamide (H 2 NCN) and its isomer, the carbodiimide molecule (HNCNH), generated from H 2 NCN. By the analysis of the relative absorbance vs. photolysis time curves, the other bands were grouped to three different species both for the O-and the S-containing systems. In the case of the O-containing isomers, these bands were assigned to the H 2 NNCO:H 2 NCN, and H 2 NCNO:H 2 NCN complexes, and to the ring-structure H 2 NC(NO) isomer. In a similar way, the complexes of H 2 NNCS and H 2 NCNS with the H 2 NCN, and H 2 NC(NS) were also identified. 1,2,4-thiadiazole-3,5-diamine was also investigated in similar way like the above mentioned precursors. The results of this study also support the identification of the new S-containing isomers. Except for H 2 NNCO and H 2 NCNS, these molecules were not identified previously. It is expected that at least some of these species, like the methyl isocyanate (CH 3 CNO) isomer b,c , are present and could be identified in astrophysical objects.

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The photochemical decomposition of 1,2,4-oxadiazole-3,5-diamine and 1,2,4-thiadiazole-3,5-diamine was investigated in low-temperature Ar and Kr matrixes at different wavelengths. The analysis of matrix-isolation infrared (MI-IR) spectra aided by high-level quantum chemical computations showed not only that these photochemical reactions yield [NH, C, N, X] (X = O, S) isomers but also that the bands of a novel, formerly unobserved species were observed. The comparison of computed IR spectra of potential products with the observed spectra suggests that these species are the diazenecarbaldehyde (HNNCHO) and diazenecarbothialdehyde (HNNCHS). Neither of the reactive HNNCHO and HNNCHS molecules was observed experimentally before. Both molecules are identified in the matrix as a complex with the other photoproduct, NHCN. Comparison of the present experiments with former photochemical experiments on 1,2,5-oxadiazole-3,4-diamine and 1,2,5-thiadiazole-3,4-diamine and the analysis of the rate of formation of the different photoproducts indicate that HNNCHO and HNNCHS are formed in a different reaction path than HNNCX and HNC(NX) (X = O, S), and not by photoisomerization from these latter products.