화학공학소재연구정보센터
Journal of Physical Chemistry A, Vol.122, No.20, 4687-4695, 2018
Mass Spectrometry and Theoretical Investigation of VNn+ (n=8, 9, and 10) Clusters
VN(n)(+)clusters were generated by laser ablation and analyzed by mass spectrometry. The results showed that VN8+, VN9+, and VN10+ clusters were formed, and the mass peak of VN8+ is dominant in the spectrum. The VN8+ cluster was further investigated by a photodissociation experiment with 266 nm photons. Density functional theory calculations were conducted at the M06-2X/6-311+G(d,p) level to search for stable structures of VNn+ (n = 8, 9, and 10) and their neutral counterparts. The theoretical calculations revealed that the most stable structure of VN8+ is in the form of V(N-2)(4)(+) with D-4h symmetry. The binding energy from the calculation is in good agreement with that obtained from the photodissociation experiments. The global minimum structures of VN8, VN9+/0, and VN10+/0 contain a similar substructure of the N-4 ring and exhibit energy properties. The most stable structure of VN9+ is in the form of (eta(2)-N-4)V+N(N-2)(2) with C-1 symmetry, while that of VN10+ is in the form of (eta(4)-N-4)V+(N-2)(3) with C-5 symmetry. For neutral VN8, VN9, and VN10, (eta(4)-N-4)V(N-2)(2), (eta(4)-N-4)V(N-3)(N-2), and (eta(4)-N-4)V(N-2)(3) are their ground-state structures, with decomposition into one V atom, and corresponding quantities of N-2 can release energies of about 50.20, 96.28, and 57.76 kcal/mol, respectively.