Stable Structure And Theoretical Study On Carbon-oxygen And Nitrogen-oxygen Cluster

As the potential high energy density materials, carbon-oxygen clusters and nitrogen-oxygen clusters is that the dissociation energy release very high energies when they proceed decomposition. The other materials can not compared to them as the potential high energy density materials. Extensitive attention has been shown in the high energy of the oxygen and nitrogen-oxygen clusters around the science field. So far chemical clusters have become very active central-level topic in the materials chemistry. Hoping to find much more high energy density materials, some material scholars home and abroad are working hard now. So calculating the structures and dissociation mechanism for the clusters (particularly for the oxygen and nitrogen-oxygen clusters ) is very significant in theoretical and practical study.In present work, a systematic and theoretical deeply investigation for stable structures of the oxygen and nitrogen-oxygen clusters and dissociation mechanism of partial oxygen and nitrogen-oxygen clusters was carried out using the ab initio and the popular DFT functionals of the quantum chemical. The content of this paper is divided into two parts:Firstly, the theoretical study on the stable structures for the oxygen cluster isomers and for the dissociation channels of partial isomers. In this section ,we study the relationship between the structures, energies, vibration frequencies and the dissociation energies of the Cn_O(nn=3,4,5),C_nO₂(nn=3,4)and C₄O₇ clusters, of which we are focus on the dissociation channels of C₄O₄,C_O5,C₃O₆ clusters . Particularly, the analysis of the dissociation mechanism of C₄O₇ is carried out detailedly. Secondly, the theoretical study on the stable structures for the nitrogen-oxygen cluster isomers and for the dissociation channels of partial isomers. In this section ,we study the relationship between the structures, energies, vibration frequencies and the dissociation energies of the N₃O_n(n=1,2,3,4),and N4O5 clusters, of which we are focus on the dissociation channels of N₃O₄,N4O5 clusters detailedly.The results can be summarized as follow:The reactants, products and transition states of the reactions have been optimized using Density Function Theory, and all of the transition states have been verified to connect with the designated reactants and products by performing intrinsic reaction coordinate (IRC) analysis at the same level. 1. C₃O₃ clusters have been computed at HF/6-31G(d) level, two equilibrium geometries were identified, one transition state of dissociation reaction of C₃O₃ clusters was also found, and the dissociation mechanism was also studied. Sixteen and thirty equilibrium geometries were identified of C₄O₄ and C₅O₅ were identified by B3LYP/6-31G(d),BB1K/6-31G(d),MPWB1K/6-31G(d) levels, the transition states of M16 obtained more attention for C4O4 cluster (P6) was the dissociation products of M16, two transition states of P6 were also found. Twenty-eight equilibrium geometries of C4O7 isomers were studied at the HF/6-31G(d) and B3LYP/6-31G(d)levels, and ten transition states of C₄O₇-7 were also computed at B3LYP/6-31G(d)level, and the corresponding dissociation pathways were fully studied, and all of the transition states have been verified to connect with the designated reactants and products by performing intrinsic reaction coordinate (IRC) analysis at the same level.As the nitrogen-oxygen clusters, N₃O_n(n=1-4)isomers were computed by B3LYP/6-31G(d) level, two equilibrium geometries of N3O1 were identified, four equilibrium geometries of N₃O₂ were identified, two equilibrium geometries of N3O3 were identified, and two equilibrium geometries of N3O4 were identified. The transition states of N3O4 were also studied at the same level. Twelve equilibrium geometries of N4O5 were identified at B3LYP/6-31G(d) level. Compared with B3LYP method, the new density functional theory methods(BB1K, MPWB1K)were also used to calculate two transition states of N₄O₅ isomersWe make great efforts to get the systemic and accurate results during the study. Actually, many valuable results are obtained. This will guide promise the development of theoretical and practical study on the carboxyethylgermanium sesquioxide.