2020-12-232020-12-232019-08-052046-2069http://hdl.handle.net/2133/19544The conformational landscape of 22 different non, mono-, and disubstituted compounds with a fivemembered ring was thoroughly explored by ab initio (MP2) and DFT (B3LYP and M06-2X) methods with the 6-311+G** basis set. Our results showed that the conformational preference of these compounds was governed mainly by the specific characteristics of the substituents, with a minor influence of the level of theory employed. After a detailed analysis of the computational data, we found an interesting preference of the electronegative substituents to take pseudo-axial positions, whereas alkyl groups preferred adopting the pseudo-equatorial locations. Such preferences were pronounced with MP2 and M06-2X and underestimated by B3LYP. Despite each level of theory affording different landscapes in many cases, as a general trend, we noticed that M06-2X afforded much higher correlation with the MP2 results than B3LYP.This is a post-peer-review, pre-copyedit version of an article published in RSC Advances. The final authenticated version is available online at: https://doi.org/10.1039/c9ra03524aapplication/pdf24134–24145engopenAccessDFT CalculationsDensity Functional Theory CalculationsMP2 CalculationsMøller–Plesset Perturbation Theory (MP)SubstituentsarticleUniversidad Nacional de RosarioRoyal Society of ChemistryStortz, Carlos A.Sarotti, Ariel MarceloAttribution-NonCommercial 3.0 Unported (CC BY-NC 3.0)