Hydrogen Bonding in Substituted Formic Acid Dimers

Abstract

The hydrogen-bonded dimers of formic acid derivatives XCOOH (X = H, F, Cl, and CH3) have been investigated using density functional theory (B3LYP) and second-order Møller-Plesset perturbation (MP2) methods, with the geometry optimization carried out using 6-311++G(2d,2p) basis set. The dimerization energies calculated using aug-cc-pVXZ (with X = D and T) basis have been extrapolated to infinite basis set limit using the standard methodology. The results indicate that the fluorine-substituted formic acid dimer is the most stable one in comparison to the others. Topological analysis carried out using Bader's atoms in molecules (AIM) theory shows good correlation of the values of electron density and its Laplacian at the bond critical points (BCP) with the hydrogen bond length in the dimers. Natural bond orbital (NBO) analysis carried out to study the charge transfer from the proton acceptor to the antibonding orbital of the X-H bond in the complexes reveals that most of the dimers are associated with conventional H-bonding except a few, where improper blue-shifting hydrogen bonds are found to be present.

Structure of Mixed Carboxylic Acid Terminated Self-Assembled Monolayers: Experimental and Theoretical Investigation

“…76 The slightly shorter value obtained for the MPA dimer is due to the standard 6-31+G-(d,p) basis set that we employed, whereas the basis sets used in ref 76 have more diffuse and polarization functions.…”

“…For example, the B3LYP/6-311++G(2d,2p) and MP2/ 6-311++G(2d,2p) methods yield interaction energies of 18.53 and 16.66 kcal/mol for the CH 3 COOH dimer. 76 When the interaction energy is extrapolated to an infinite basis set, the MP2 method yields a value of 17.57 kcal/mol. This implies that the cyclic dimers of carboxylic acids have strong hydrogen bonds of around 8 kcal/mol.…”

Structure and NLO properties of halogen (F, Cl) substituted formic acid dimers

“…Earlier studies by Marushkevich et al [72] and Senthilkumar et al [73] also confirm that the trans-trans dimers interact strongly.…”

Effect of alkyl chain on the NLO property of nonylphenol isomers: a DFT study

“…Further, the values of the electron density and the Laplacian of the electron density for the HÁÁÁp interactions are positive and lie well within the hydrogen bond criteria for the q (0.002-0.34) and r 2 q(0.017-0.13) a.u., respectively [49][50][51][52][53][54]. This shows that all the C-HÁÁÁp interactions have hydrogen bond character.…”