Structure of the 2-isopropylaminoethanol isolated molecule: Conformational analysis and intramolecular interactions

In this paper, a systematic exploration of all the possible conformers of 2-isopropylaminoethanol (2-IPAE) was carried out using the Density Functional Theory (B3LYP) and the 6-311++G(d,p) basis set. At this level, 66 unique conformers within a Gibbs energy range of ca. 31 kJ mol−1 were found in the potential energy surface and their geometrical and thermodynamic properties were determined and discussed. A significant molecular strain was evidenced by the dihedrals and distances between non-bonded hydrogen atoms. According to the geometrical parameters, a O-H···N hydrogen bond was found to be present in the three most stable conformers, representing 68% of the conformational composition at 298.15 K. The energetic and geometrical data derived from the DFT calculations were further complemented by a NBO analysis of the most stable conformers.