Weak hydrogen bonding competition between O–H⋯π and O–H⋯Cl

Abstract

The weak intermolecular interaction between 2,2,2-trifluoroethanol (TFE) and 3-chloro-2-methyl-1-propene (CMP) has been investigated by gas phase FTIR spectroscopy and DFT calculations. CMP offers two hydrogen bond docking sites to the hydrogen bond donor: the chlorine atom (O-H/Cl) and the C]C p electron system (O-H/p). DFT calculations suggest that MeOH approaches CMP in five different orientations. The structural, energetic, and spectroscopic parameters of the most stable structures in each orientation were studied, and their binding energies range from À25.5 to À19.5 kJ mol À1. The docking to the p system is at least 1 kJ mol À1 more favored than the docking to the chlorine atom. The equilibrium constant for complexation (2.3 Â 10 À2 ) was determined from the experimental and calculated intensity of the OH-stretching transition. The Gibbs free energy of formation was found to be 9.3 kJ mol À1. The nature of the non-covalent interaction was analyzed with the atoms in molecules (AIM) method.

Conformational preferences in a series of α-hydroxy ketone derivatives: interplay of conformational energies and lattice cohesive energies

“…Although the nature and significance of C–H⋯π interactions have been well studied, 49–52 our analysis quantifies the interaction strengths of the dimers formed by these weak hydrogen bonds. It is also notable that the O–H⋯π interaction 53–57 distances of 2.513 Å and 2.755 Å observed in structures 1 and 3 respectively are well within the distance range observed for such interactions in the literature. A survey of the O–H⋯π and C–H⋯π interaction distances in the CSD for crystal structures refined using neutron diffraction data are given in the ESI †…”

Looking for the Azeotrope: A Computational Study of (Ethanol)6–Water, (Methanol)6–Water, (Ethanol)7, and (Methanol)7 Heptamers

“…In this respect, molecular structure calculations can be a useful tool to provide a reliable description of the different weak interactions, including the very common and important OH···O HBs, which contribute to the stability of these clusters. For example, making use of the quantum theory of atoms in molecules (QTAIM) and/or noncovalent interactions reduced density gradient (NCI-RDG), several more weak interactions are being revealed and analyzed (strength, stability, directionality) in clusters stabilized by weak interactions such as CH···O, NH···O, OH···π, OH···Cl, π···π, and H···H. ,,− …”

Exploration of the Synergy Between 2D Nanosheets and a Non-2D Filler in Mixed Matrix Membranes for Gas Separation

“…. O was reported to be much higher (20∼30 kJ mol −1 ) (Zhao et al, 2017). Therefore, it is reasonable to speculate that the hydrogen bonding between PEO and hydroxyl group-containing fillers will affect the formation of CO 2 -ether complex, which may decrease both the solubility coefficient and solubility selectivity.…”