Intra- and Intermolecular Hydrogen Bonding in 2-Phosphinylphenol:  A Quantum Chemical Study

Abstract

A computational study of 2-phosphinylphenol has been carried out to investigate intramolecular hydrogen bond formation and its consequences in the rest of the molecule. This is an extension of both our synthetic work on organophosphorus derivatives of diphenyl ether and our experimental and computational structure analyses of salicylaldehyde, 2-nitrophenol, and related molecules. Full optimization of the 2-phosphinylphenol geometries was carried out both at the HF/6-31+G** level and, to include electron correlation, at the MP2/6-31G* level. The stabilization energy of the intramolecular hydrogen bonding in 2-phosphinylphenol (28.4 kJ/mol by isodesmic calculation) is smaller than that of the intermolecular hydrogen bonding in the dimer of 2-phosphinylphenol, also computed in this work to be 59.1 kJ/mol per hydrogen bond from the counterpoise interaction energy or 57.4 kJ/mol by BSSE-corrected isodesmic calculation. The closure of the six-membered ring with the intramolecular hydrogen bond apparently introduces energy-costing constraints. The geometrical changes in 2-phosphinylphenol accompanying the formation of the hydrogen bond are similar to those observed in 2-nitrophenol and salicylaldehyde, characterized as resonance-assisted hydrogen bonding. In addition to the lowest energy monomer with the hydrogen bond, two further stable minima of higher energy with no hydrogen bonding were found for 2-phosphinylphenol.

Structural Characteristics of Intramolecular Hydrogen Bonding in Benzene Derivatives

“…30 (ii) The barrier to internal rotation of the BX n groups in the hydrogen-bonded derivatives increases considerably with respect to that of the BX n parents. [7][8][9]17,31 (iii) The simultaneous HB interactions in the resorcinol derivatives of NO 2 and CF 3 result in about twice as large changes in the common geometrical parameters (C-N and C-C bonds, O-N-O and F-C-F angles, etc.) than in the respective phenol derivatives containing a single interaction.…”

“…22 Changes in the reference geometry upon introduction of the diffuse functions were found to be negligible. 13,17 Moreover, these marginal geometrical changes are not reflected in the computed single-point energies, as revealed by test calculations on 2-nitrophenol and 2-trifluoromethylphenol. 12…”

Hydrogen Bonding in Monomers and Dimers of 2-Aminoethanol

“…Ab initio studies can be of value in describing the competition between inter- and intramolecular hydrogen bonds and the cooperative character of such interactions. Many studies on clusters of other molecules capable of intermolecular hydrogen bond formation have been reported. − However, high-level computational studies of molecular complexes where both inter- and intramolecular hydrogen bonds are present are relatively rare. , …”

“…[25][26][27][28][29][30] However, high-level computational studies of molecular complexes where both inter-and intramolecular hydrogen bonds are present are relatively rare. 31,32 This study focuses on the conformational analysis of isolated molecules of AE as well as selected AE dimers by using density functional theory (DFT) and an extended basis set, with the main emphasis on the intra-and intermolecular hydrogenbonding interactions. Natural bond orbital (NBO) theory was applied to analyze hydrogen-bonded conformers in terms of orbital interactions.…”

Theoretical Study of Hydrogen Bond Formation in Trimethylene Glycol-Water Complex

“…Several theoretical studies of hydrogen bond interaction have been carried out for different systems like water complex [12,13], dichlorine monoxide-hydroxyl radical system [14], tetrahydrofuranwater complex [15,16], and methanol-water complex [17]. In one word, the literature of quantum chemical analysis of hydrogen bond interaction for various complex is well enriched [18][19][20][21][22][23]. Electronic structure-based studies on hydrogen bond formation between a molecule having two hydroxyl groups (like trimethylene glycol) and water have 2 ISRN Physical Chemistry not been reported in the literature.…”