The N-(2-benzoyl-phenyl) oxalyl derivatives are important models for studying of three-centered intramolecular hydrogen bonding in organic molecules. The quantum theoretical calculations for two crystal structures of N-(2-benzoyl-phenyl) oxalyl (compounds I and II) were performed by Density Functional Theory (B3LYP method and 6-311+G* basis set). From the optimized structures, geometric paramet...

Hydrogen bonds are weak, generally intermolecular bonds, which hold much of soft matter together as well as the condensed phases of water, network liquids, and many ferroelectric crystals. The small mass of hydrogen means that they are inherently quantum mechanical in nature, and effects such as zero-point motion and tunneling must be considered, though all too often these effects are not consi...

In the crystal structure of the title compound, C(11)H(14)N(2)OS, the two N-H bonds are anti to each other. There is an intramolecular N-H⋯O hydrogen bond generating an S(6) ring motif.In the crystal, mol-ecules are linked via N-H⋯S hydrogen bonds with an R(2) (2)(8) motif and N-H⋯O hydrogen bonds with an R(2) (2)(12) motif into chains running along [1-10].

In the structures of 5-(1-hydroxyethylidene)-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione, C8H10N2O4, (I), 1,3-dimethyl-5-[1-(propylamino)ethylidene]pyrimidine-2,4,6(1H,3H,5H)-trione, C11H17N3O3, (II), and 5-[1-(2,2-dimethoxyethylamino)ethylidene]-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione, C12H19N3O5, (III), there are no direction-specific intermolecular interactions. The molecules in 5-[1...

It is well known that the existence of hydrogen bonds causes the vibrational spectra for the donor OH bond to broaden. Most times this broadening is attributed to inhomogeneous contributions, however in this paper, we studied the homogeneous contribution coming from the decay lifetime of the OH stretching excitation. Alkane diol, which possesses an OH(b)OH(f) (b and f stand for hydrogen bonded ...

using hartree–fock (hf) and ِِdensity functional theory (dft) calculations the thermodynamic properties such as thermal energy , , thermal enthalpy , , thermal entropy , , thermal gibbs free energy , , heat capacity ,cv, and molecular structures of several species involving in keto↔enol tautomerism related to acetaldehyde (a), 5,5-dimethyl-1,3-cyclohexanedione (dimedone) and  acetylacetone (aa) h...