The photodissociation of cis-(NO)2 in N2 and Ar matrices under 266 nm pulsed laser irradiation is reported- Results show the electronically excited o(1D) atom may be formed in the primary photolysis step. In the N2 matrix, the highly active o(1D) atoms could either react with N2 lattice molecules forming N2O or recombine with nearby N2O forming cis-(NO)2 and trans-(NO)2. However, in the Ar matrix the nascent state o(1D) atom, due to the lack of reactant, quenches to O(3P) as moving through the lattice site and the yield of N2O is less than that in N2 matrix.
The geometries and fundamental vibrational frequencies of trans-and C2v- nitrous acid have been determined by ab initio calculations at the MP2 level with 6-31G** and 6-311+G** basis sets. The calculation results satisfactorily reproduce the experimental structural and vibrational spectral features of trans-HONO. Calculations at the same levels indicate that the C2v-HNO2 is also a stable conformer of nifrous acid. The calculated frequencies of C2.-HNO2 are in good agree-ment with the matrir infrared spectral features.
The mass spectra of both positive and negative charged Ta-containing ions from laser ablatiou of Ta2O5 were measured using a time-of-flight mass spectrometer. Formation of iomc Ta-containing oxides such as TaO and TaO from Ta2O5 ablation in ambient O2 were observed for the first time. The influence of ambient O2 pressure on the intensities of ablated Ta-containing ions has also been studied. It is found that the subsequent oxidation reactions were involved in the ablation of Ta2O5 at different O2 pressure. The enthalpies of possible okidation reactions were theoretically calculated, and the possible formation reastions of the ionic Ta-contauing oxides are discussed.
