Crossed beams study on the dynamics of the F-atom reaction with ammonia.

The F-atom reaction with NH(3) and ND(3) has been studied using the universal crossed beams technique. Angular resolved time-of-flight spectra were measured for the HF and DF reaction products. Product angular distribution and product kinetic energy distribution in the center-of-mass frame were determined from the experimental TOF spectra. Experimental results show that the HF and DF products are largely forward-scattered relative to the F-atom beam direction with a considerable amount of product at sideway and backward scattering directions. High-level ab initio calculation on the reaction energy pathway suggests that the forward-scattered products are mainly produced via a direct abstraction mechanism at large impact parameters, whereas sideway- and backward-scattered products are likely due to a long-lived complex formation mechanism.

DFT study on activation of carbon dioxide by (tBuArN)3M≡N (M=Nb,V,Ta): the electronic structure and activity.

The reaction mechanism for the reduction of CO(2) gas activated by (tBuArN)(3)M≡N was studied by the means of density functional theory (DFT) calculations. The calculations indicated that this reaction has a two step reaction mechanism. From our calculations, we found that (tBuArN)(3)Ta≡N held the best activity among the three (tBuArN)(3)M≡N complexes studied. Our results also indicated that the reaction of (tBuArN)(3)M≡N with CO(2) occurred under orbital control involving the HOMO-3 orbital of (tBuArN)(3)M≡N, which could give higher overlapping with the LUMO of the CO(2) molecule. The substitutions on the amino donor ligands studied here took larger effect on the HOMO structure of the (tBuArN)(3)M≡N molecules. The electronic structure of the (tBuArN)(3)M≡N complexes also showed their ability for activating CO(2) molecules, in the order of M = V < Nb < Ta.