Density functional theory simulations of two‐dimensional infrared spectra for hydrogen‐bonded acetic acid dimers

Abstract

Two-dimensional coherent infrared spectra are simulated based on density functional theory calculations to analyze vibrational couplings in hydrogenbonded acetic acid dimers. Anharmonic sixth-order force fields covering up to threebody interactions are calculated for up to 11 normal modes. Three mechanisms for vibrational coupling within the two intermolecular hydrogen bonds are considered: anharmonic coupling of the high-frequency OOH stretching mode to low-frequency modes, Fermi resonance coupling the of OOH stretching mode to fingerprint mode combination tones, and a combination of both. Predicted coherent two-dimensional infrared spectra show distinct signatures for the different coupling mechanisms.

Car-Parrinello and path integral molecular dynamics study of the hydrogen bond in the chloroacetic acid dimer system

“…9 Dreyer et al have investigated the complex line shape of the O-H stretching band in the gas phase cyclic dimer of acetic acid through a combined coherent femtosecond IRpump-IR-probe spectroscopy and quantum mechanical modeling study. 3,4 In particular, this work identified two modes which couple strongly to O -H, which are the hydrogen bond bending ͑␦ dimer ͒ and stretching ͑ dimer ͒ modes, at wave numbers of 145 and 170 cm −1 , respectively. Both of these low energy normal modes of vibration modulate the hydrogen bond distance strongly.…”

“…Experimental evidence is hard to obtain, as the observation of ultrafast vibrational dynamics requires the use of advanced methods based on multidimensional nonlinear coherent laser spectroscopies. There have been several recent studies on cyclic carboxylic acid dimers [3][4][5] and other simple systems, 6,7 which have given rise to the discovery that the O-H stretching motions are coupled anharmonically to lower frequency vibrational modes, that are in turn responsible for modulating the length of the hydrogen bond. This basic structural mechanism establishes a continuum of potential energy surface ͑PES͒ shapes, from the double well at hydrogen bond lengths around 2.6 Å, to the single well around 2.4 Å.…”

Hydrogen-bonded assembly and binding affinity of the multi-point acceptor and isophthalic acid

“…Research on the hydrogen-bonded assembly has brought out a multitude of new materials for the advanced scientific and technological realm [1][2][3][4][5]. Hydrogen bonding is particularly significant to the study on the molecular recognition in the living organism [6,7].…”

“…Bielawski et al [4] prepared the hydrogen-bonding complex formed by oligophenyleneethynylene and isophthalic acid, and studied the effects of different polar solvents upon association constants. Dreyer et al [5] researched into the hydrogen bonding interaction of the dimer formed by two acetic acid molecules using density function theory, in addition to the different vibrating and coupling mechanisms via IR spectra. Inouye et al [6] proved that the multi-pyridine macrocyclic acceptor could recognize a furan nucleotide via hydrogen bonds, and determined the stabilization constant as well as thermodynamic parameters.…”

First-Principles Approach to Vibrational Spectroscopy of Biomolecules

“…Anharmonic force constants up to sixth order with up to three different normal mode indices have been included into predictions of 2D-IR spectra of acetic acid dimers based on DFT calculations [104]. The calculation of fundamental frequencies and anharmonic vibrational constants may be achieved either by vibrational self-consistent field methods or by vibrational perturbation theory (see [105] for a comparison of both).…”