Study of Water and Dimethylformamide Interaction by Computer Simulation

Abstract

Monte Carlo simulations of water-dimethylformamide (DMF) mixtures were performed in the isothermal and isobaric ensemble at 298.15 K and 1 atm. The intermolecular interaction energy was calculated using the classical 6-12 Lennard-Jones pairwise potential plus a Coulomb term. The TIP4P model was used for simulating water molecules, and a six-site model previously optimised by us was used to represent DMF. The potential energy for the water-DMF interaction was obtained via standard geometric combining rules using the original potential parameters for the pure liquids. The radial distribution functions calculated for water-DMF mixtures show well characterised hydrogen bonds between the oxygen site of DMF and hydrogen of water. A structureless correlation curve was observed for the interaction between the hydrogen site of the carbonyl group and the oxygen site of water. Hydration effects on the stabilisation of the DMF molecule in aqueous solution have been investigated using statistical perturbation theory. The results show that energetic changes involved in the hydration process are not strong enough to stabilise another configuration of DMF than the planar one.

The Impact of Synthesis Method on the Properties and CO2 Sorption Capacity of UiO-66(Ce)

“…That reaction is impossible to avoid in the presence of water, which was used as one of the solvents in this work. As was calculated [36], hydrogen bonds between water and amides are stronger than water molecules. The rate of DMF hydrolysis increases with temperature; therefore, the risk of cerium formate crystallization was higher during hydrothermal syntheses of UiO-66(Ce), than during sonochemical procedure.…”

Structure and weak hydrogen bonds in liquid acetaldehyde

“…The features of weak hydrogen bonds and the criteria used to classify them have been extensively discussed very recently by many authors [46][47][48][49][50][51][52][53][54][55][56][57] and have already been used by us in previous works. 12,14 It is important to recall that hydrogen bonds are additive interactions 45 and, because of this characteristic, even weak hydrogen bonds can play an important role in stabilising the structure of a material. This can be the reason behind the observation that the methyl carbon is closer to oxygen than the carbonyl carbon.…”

“…12,13 Results on thermodynamics and structural aspects have been published. [12][13][14][15] The study has been centred in amides, since these molecules are suitable models for peptide moieties, and dimethyl sulfoxide because these liquids are popular solvents in organic chemistry with stressed effects in reaction kinetics. 16 In this work, new additive pairwise potential has been parameterised for acetaldehyde.…”

“…Soc. systems, and extend the data earlier published. 12,14 In a future paper, thermodynamics results for aqueous solutions of acetaldehyde, formamide and methylformamide will be reported. The results presented here were obtained by Monte Carlo simulation, 17 which, along with molecular dynamics, 18 is a very popular computational method in this area.…”

Engineering multistructure poly(vinylidene fluoride) membranes modified by polydopamine to achieve superhydrophilicity, excellent permeability, and antifouling properties

“…In addition, the repulsive interaction between the hydrophobic groups (CH) of DMF and water induces an energy release. 41 Therefore, DMF/water system (M3) also shows the typical finger-like structure owing to the large heat of mixing between DMF and water. The exothermic heat of DMAc/water is smaller, so M2 only has the short finger-like macrovoids in the top layer.…”