Crystalline N-alkyl-N-arylthioureas with ortho hydroxyl and para or meta methyl substituents to the phenyl ring were studied by single crystal X-ray diffraction, IR and solid state C CP MAS NMR. Two different modes of association were found: i) intermolecular NH...S bonds and NH not involved in hydrogen bonding in N-methyl-N(2-hydroxy,5-methylphenyl)thiourea 1, ii) cyclic dimers with two NH...S...

−Poly-Ethylene Glycol (PEG) 300+H2O solutions (PEGWs) has been used as a promising medium for the absorption of SO2. We investigated the UV, FTIR, 1H-NMR, and fluorescence spectra in the absorption processes of SO2 in PEGWs to present an important absorption mechanism. Based on the spectral results, the possibility of intermolecular hydrogen bond formation by hydroxyl oxygen atom in the PEG mol...

The structures of the mono- and the dihalogenated N-unsubstituted 2-aminobenzamides were characterized by means of the spectroscopic (¹H-NMR, UV-Vis, FT-IR, and FT-Raman) and X-ray crystallographic techniques complemented with a density functional theory (DFT) method. The hindered rotation of the C(O)-NH₂ single bond resulted in non-equivalence of the amide protons and therefore two distinct re...

the concept of resonance assisted hydrogen bond (rahb), which usually occurs in b diketons, has a remarkable role in chemistry. these molecules, which contain heteroatom particularly o and n, are species with biological interest in protein folding and dna pairing. therefore, the amplification of hydrogen bonds strength by substituents may be important in life sciences. in the current research, ...

It is found that the 750 cm–1 band in pure tertiary butyl alcohol shows attributes of a complex structure can be interpreted as result superposition several closely located lines belonging to different aggregates alcoholmolecules. As diluted with neutral solvents, width this passes through maximum corresponds concentration mixture comparable contents various most stable solution. The performed ...

the one-dimensional model of lippincott and schroeder for hydrogen bond has been re-examined and it has been shown that o-h bond distance depends on repulsive van der waals and attractive electrostatic potentials.it has been shown that constant b in the van der waals repulsion potential is not transferable to all hydrogen bonds. the possibility of obtaining the semi-empircal parameters in the l...

A combined DFT quantum mechanical and AMBER molecular mechanical potential (QM/MM) is presented for use in molecular modeling and molecular simulations of large biological systems. In our approach we evaluate Lennard-Jones parameters describing the interaction between the quantum mechanical (QM) part of a system, which is described at the B3LYP/6-31+G* level of theory, and the molecular mechani...

Cooperative effects in two-dimensional cyclic networks containing intermolecular three-centered hydrogen bonding interactions of the type H1...A...H2 are investigated by means of ab intio molecular orbital and density functional theory calculations. Ring-like clusters consisting of three and up to nine monomers of the cis-cis isomer of carbonic acid H2CO3 are used as basic models, where each un...

The purpose of this study is to confirm the impact of polar functional groups on inter and intra-molecular hydrogen bonding in haloperidol (HP) and droperidol (DP) and, hence, their effects on dissolution using a new approach. To confirm our theory, a new molecule: deshydroxy-haloperidol (DHP) was designed and its synthesis was requested from a contract laboratory. The molecule was then studied...