Molecular dynamics (MD) simulations combined with water-water H-bond angle analysis and calculation of solvent accessible surface area and approximate free energy of solvation were used to determine the influence of hydroxyl orientation on solute hydration and surrounding water structure for a group of chemically identical solutes-the aldohexopyranose sugars. Intramolecular hydrogen bond cooper...

Density Functional Theory (DFT) calculations have been carried out using a Polarizable Continuum Model (PCM) in an attempt to investigate the electro-molecular properties of branched-chain glucoside (C14C10-D-glucoside) isomers. The results showed that αconfiguration of pyranoside form is thermodynamically the most stable, while the solution should contain much more β...

in the present work, dft calculations are employed to obtain the optimized structures of 4-acyl pyrazolone tautomers (19 tautomers) using b3lyp/6-311++g** calculations. inaddition, molecular parameters, ir frequencies and relative energies are extracted for alltautomers. the existence of aromatic ring, keto tautomer (versus enol tautomer), n-h bond(versus c-h bond) and c=n double bond (versus n...

Using the freon mixture CDF(3)/CDClF(2) as solvent we have been able to measure the (1)H and (15)N NMR spectra of the doubly (15)N labeled 2,2'-bipyridinium cation (BpyH(+)) at temperatures down to 115 K. The obtained NMR parameters strongly depend on the type of counteranions indicating the formation of ion pairs. In the case of the bulky poorly coordinating tetrakis[3,5-bis(trifluoromethyl)ph...

The title pyrimidine derivative, C7H8N4S, is essentially planar, with a maximum deviation of 0.029 (2) Å from the mean plane of the non-H atoms. In the crystal, mol-ecules are linked by an inter-molecular bifurcated N-H⋯N hydrogen bond between the cyano N atom and the two amino groups, an N-H⋯N hydrogen bond between the two amino groups and a weak C-H⋯π inter-action, forming a three-dimensional...

In the title compound, C10H9N3O3S, the five-membered ring adopts a slightly twisted conformation about the Cm-S (m = methyl-ene) bond. The dihedral angle between this ring and the benzene ring is 7.99 (9)°. A bifurcated intra-molecular N-H⋯(O,S) hydrogen bond helps to establish the near planar conformation of the mol-ecule. In the crystal, mol-ecules are linked by N-H⋯O and O-H⋯O hydrogen bonds...

Various ab initio calculations using the density-functional (DFT), the second order Möller-Plesset perturbation (MP2) and self-consistent reaction field (SCRF) theories were performed on thirteen theoretically possible inositol stereoisomers. Gas phase calculations reveal that the myo- and neo-isomers of inositol (bearing one and two axial hydroxyl groups, respectively) are marginally more stab...

In the title compound, C(18)H(19)FN(2)O, the hydrazide side chain is approximately perpendicular to the central ring [dihedral angle = 76.80 (5)°]. The F atom is disordered over two positions with occupancies of 0.818 (2) and 0.182 (2). The packing consists of chains of mol-ecules parallel to the a axis, connected by a bifurcated N-H⋯(O,N) hydrogen bond and a weak C(phen-yl)-H⋯O hydrogen bond. ...

A (1) (TS) J F,H(O) coupling pathway, dictated by a hydrogen bond, in some 2-fluorobenzoic acids has been observed, while such an interaction does not occur in 2-fluorophenol. Thus, this work reports the conformational analysis of 2-fluorophenylboronic acid (1), in order to evaluate a possible intramolecular OH∙∙∙F hydrogen bond in comparison to an nF→pB interaction, which mimics the quantum nF...

In the title compound, C(10)H(12)N(2)OS(2), the thione and S-methyl groups are syn. An intra-molecular bifurcated O-H⋯(S,N) hydrogen bond occurs.