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Theoretical study of the relative stabilities of H + ( X ) 2 and H + ( X ) 3 conformers and their clustering energies: X CO and N 2
Author(s) -
Ikuta Shigeru
Publication year - 1985
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.540060206
Subject(s) - basis set , chemistry , perturbation theory (quantum mechanics) , electronic correlation , singlet state , crystallography , atom (system on chip) , conformational isomerism , proton , molecule , atomic physics , computational chemistry , density functional theory , physics , excited state , quantum mechanics , organic chemistry , computer science , embedded system
Abstract Third‐order Møller–Plesset perturbation theory ( MP 3) with a 6‐31G** basis set was applied to study the relative stabilities of H + ( X ) 2 conformations ( X CO and N 2 ) and their clustering energies. The effect of both basis set extensions and electron correlation is not negligible on the relative stabilities of the H + (CO) 2 clusters. The most stable conformation of H + (CO) 2 is found to be a C ∞ v structure in which a carbon atom of CO bonds to the proton of H + (CO), whereas that of H + (N 2 ) 2 is a symmetry D ∞ h structure. The second lowest energy conformations of H + (CO) 2 and H + (N 2 ) 2 lie within 2 kcal/mol above the energies of the most stable structures. Clustering energies computed using MP 3 method with the 6‐31G** basis set are in good agreement with the experimental findings of Hiraoka, Saluja, and Kebarle. The low‐lying singlet conformations of H + ( X ) 3 ( X CO and N 2 ) have been studied by the use of the Hartree–Fock MO method with the 6‐31G** basis set and second‐order Møller–Plesset perturbation theory with a 4‐31G basis set. The most stable structure is a T‐shaped structure in which a carbon atom of CO (or a nitrogen atom of N 2 ) attacks the proton of the most stable conformation of H + ( X ) 2 clusters.