Theoretical study of aromaticity in small hydrogen and metal cation clusters X+3 (X=H, Li, Na, K, and Cu)

Autor: Shao Dan Wu, Liu Yong, Xian Xing Chi
Rok vydání: 2006
Předmět:
Zdroj: International Journal of Quantum Chemistry. 107:722-728
ISSN: 1097-461X
0020-7608
DOI: 10.1002/qua.21166
Popis: Five cation clusters X (X=H, Li, Na, K, and Cu) with two possible isomers, i.e., regular trigonal structure (D3h) and linear structure (D∞h), have been investigated using four methods: B3LYP, B3PW91, MP2, CCSD(T) and basis set 6-311+G(3df). The calculations show that only the regular trigonal structure (D3h) is stable. The related neutral clusters X3Cl (X=H, Li, Na, K, and Cu) are also investigated using two methods: B3LYP, MP2, and basis set 6-311+G(3df). For H3Cl species, there is no a stable structure to be found. For other four X3Cl (X=Li, Na, K, and Cu) species, there are two stable isomers, for which the bidentate structures (C2v-1) [see Fig. 1(d)] are global minima. According to the general criteria for aromaticity including resonance energy (RE) and nucleus-independent chemical shift (NICS), the five trigonal isomers exhibit a higher degree of aromaticity. Molecular orbital analysis reveals that the five trigonal X(X=H, Li, Na, K, and Cu) isomers possess only σ-aromaticity originating from s orbitals. For the Cu ring the d orbitals do not play a significant role in the electron delocalization effects. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Databáze: OpenAIRE
Externí odkaz: