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An ab initio study of intermolecular interactions of nitromethane dimer and nitromethane trimer
Author(s) -
Li Jinshan,
Zhao Feng,
Jing Fuqian
Publication year - 2003
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.10179
Subject(s) - nitromethane , trimer , intermolecular force , dimer , chemistry , ab initio , interaction energy , basis set , binding energy , computational chemistry , ab initio quantum chemistry methods , atom (system on chip) , crystallography , density functional theory , molecule , atomic physics , organic chemistry , physics , computer science , embedded system
Different geometries of nitromethane dimer and nitromethane trimer have been fully optimized employing the density functional theory B3LYP method and the 6‐31++G** basis set. Three‐body interaction energy has been obtained with the ab initio supermolecular approach at the levels of MP2/6‐31++G**//B3LYP/6‐31++G** and MP2/aug‐cc‐pVDZ//B3LYP/6‐31++G**. The internal rotation of methyl group induced by intermolecular interaction has been observed theoretically. For the optimized structures of nitromethane dimer, the strength of CH…ON H‐bond ranges from −9.0 to −12.4 kJ mol −1 at the MP2/aug‐cc‐pVDZ//B3LYP/6‐31++G** level, and the B3LYP method underestimates the interaction strength compared with the MP2 method, while MP2/6‐31++G**//B3LYP/6‐31++G** calculated Δ E C is within 2.5 kJ mol −1 of the corresponding value at the MP4(SDTQ)/6‐31G**//B3LYP/6‐31++G** level. The analytic atom–atom intermolecular potential has been successfully regressed by using the MP2/6‐31++G**//B3LYP/6‐31++G** calculated interaction energies of nitromethane dimer. For the optimized structures of nitromethane trimer the three‐body interaction energies occupy small percentage of corresponding total binding energies, but become important for the compressed nitromethane explosive. In addition, it has been discovered that the three‐body interaction energy in the cyclic nitromethane trimer is more and more negative as intermolecular distances decrease from 2.2 to 1.7 Å. © 2003 Wiley Periodicals, Inc. J Comput Chem 24: 345–352, 2003