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The adsorption and thermal decomposition of alcohols (CH 3 OH, C 2 H 5 OH, and C 4 H 9 OH) on Ge(100) were investigated with temperature-programmed desorption and Xray photoelectron spectra. At 105 K, CH 3 OH adsorbs both molecularly and dissociatively on Ge(100). Chemisorbed CH 3 OH molecules dissociate to form surface CH 3 O and hydrogen in a temperature range 150−300 K. Surface CH 3 O can dehydrogenate to yield CH 2 O as two desorption features, which depend on coverage. At small coverage, surface CH 3 O undergoes mainly α-hydrogen elimination to desorb CH 2 O at 490 K. At large coverage, another desorption of CH 2 O occurs predominantly at 525 K, which is initiated by a recombinative desorption of CH 3 OH. A calculation with density functional theory at the B3LYP/6-311+G** level shows that the dissociation of the O−H bond has a much smaller barrier (<40 kJ/mol) than those for C−O bond cleavage (>150 kJ/mol). Desorption of CH 2 O results from the moderate barriers (∼110 kJ/mol) for cleavage of the C−H bond of surface CH 3 O and weak adsorption energy of CH 2 O (−56 kJ/mol). The recombination of surface CH 3 O with H occurs at large coverage with an energy barrier 127−140 kJ/mol. Similarly to CH 3 OH, C 2 H 5 OH and C 4 H 9 OH undergo the mechanism of thermal reactions through formation of alkoxyl intermediates. The longer-chain alkoxyl decomposes to desorb aldehyde at lower temperature because the interaction of its alkoxyl chain with the surface is stronger. On annealing to ∼570 K, all alkoxyl groups are completely removed from the surface via dehydrogenation and recombination to desorb aldehyde and alcohol, respectively. At a large coverage, the longer-chain alkoxyl undergoes dehydrogenation to a larger extent than recombinative desorption.

A copper-catalyzed chemoselective synthesis of 4-trifluoromethyl pyrazoles via cycloaddition of 2-bromo-3,3,3-trifluoropropene with N-arylsydnones has been developed.

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The preparation of 2,2,2-trifluoroacetaldehyde O-(aryl)oxime, a previously inaccessible precursor of trifluoroacetonitrile, via reaction of hydroxylamine and trifluoroacetaldehyde hydrate is reported. This precursor released CF 3 CN in quantitative yield under mildly basic conditions. The precursor was successfully used in the synthesis of trifluoromethylated oxadiazoles. The facile, cost-effective, scalable, and recyclable procedure makes these trifluoroacetonitrile precursors generally applicable.