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The infrared spectrum of the first C−H stretching overtone of nitromethane (CH3NO2) was measured in the wavenumber region 6047−6055 cm-1 with a resolution of 5 MHz using a molecular beam laser spectrometer equipped with bolometric optothermal detection and a power build-up cavity. The assignment of the spectrum was made using ground-state combination differences and an asymmetric rotor energy level simulation program. The following parameters were obtained for the m = 0 upper state:  ν0 = 6050.1378(24) cm-1, A = 0.55399(84) cm-1, B = 0.2936(15) cm-1, C = 0.2567(13) cm-1. The intramolecular vibrational energy redistribution (IVR) rate of the C−H stretch was calculated from the spectrum. The IVR rate of the different J K a K c levels in the spectrum ranged from 170 to 300 ps, comparable to the rate measured for methyl C−H stretching overtones in molecules of similar size (CH3SiH3 and CH3CD3).

The adsorption of silver and gold atoms, and M2, M6, and M13 (M=Ag or Au) clusters on the (0001) graphite surface has been investigated computationally using the density functional theory (DFT) with periodic boundary conditions and plane wave basis functions. The surface has been modeled as a single carbon sheet. The role of dispersion forces has been studied with an empirical classical model. The results show that the clusters avoid hollow sites on the graphite surface, and that the metal atoms favor atop and bond sites. Large structural changes are observed in octahedral M6 and icosahedral M13 clusters on the graphite surface when compared with gas-phase geometries. The results also indicate that if accurate results are required, the dispersion forces between metal and carbon atoms should be included in the studied systems.

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