Zhengzhou Univ, Sch Mech & Engn Sci, Zhengzhou 450001, Henan, Peoples R China;Dalian Maritime Univ, Sch Sci, Dalian 116026, Liaoning, Peoples R China;Zhengzhou Univ, Sch Mech & Engn Sci, Zhengzhou 450001, Henan, Peoples R China;Univ Sci & Technol China, State Key Lab Fire Sci, Hefei 230026, Anhui, Peoples R China;
Bian, Huiting;Ye, Lili;Zhong, Wei;Sun, Jinhua;
To deeply reveal the impact of the substituents and their special orientations in ring on conformational behaviors for substituted cyclohexanes, a comprehensive study of ethylcyclohexane, cis-, and trans-1,2-dimethylcyclohexanes has been carried out. All conformational structures for them were captured by the accurate ab intio method, that is, B3LYP/6-311++G(d,p) method was used for geometry optimizations, and MP2/6-311++G(d,p), G4, and CCSD(T)/6-311++G(d,p) methods were applied for the high-level single point energy refinements. Based on CCSD(T)/6-311++G(d,p) quantum results, the conformational populations of minima for these three substituted cyclohexanes were calculated by Boltzmann distribution over 300-2500 K. Additionally, the conformational inversion-topomerization pathways for them were thoroughly investigated. The complete characterization involved in their potential energy surfaces are clearly presented by three or two-dimensional schemes. (C) 2018 Elsevier Ltd. All rights reserved.