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 scie...

Catalytic fields illustrate topology of the optimal charge distribution of a molecular environment reducing the activation energy for any process involving barrier crossing, like chemical reaction, bond rotation etc. Until now, this technique has been successfully applied to predict catalytic effects resulting from intermolecular interactions with individual water molecules constituting the fir...

In the title compound, C(12)H(15)ClNO(+)·C(4)H(5)O(6) (-), the cyclo-hexa-none ring adopts a chair conformation. The benzene ring is significantly twisted so that it is in an almost perpendicular position to the C-N bond with a C(Ar)-C(Ar)-C-N torsion angle of -96.5 (5)°. Intermolecular N-H⋯O and O-H⋯O hydrogen bonds are observed in the crystal structure.

In the title compound, C(14)H(8)F(5)NO, the dihedral angle between the planes of the penta-fluoro-phenyl and phenyl rings is 18.34 (5)°. An inter-molecular N-H⋯O hydrogen bond between the amide groups connects these mol-ecules to form an infinite chain through the crystal structure. One weak intermolecular C-H⋯O contact and one π-π interaction [centroid-centroid distance = 3.772 (3) Å] are also...

Two-dimensional infrared photon echo and pump probe studies of the OH stretch vibration provide a sensitive probe of the correlations and couplings in the hydrogen bond network of liquid water. The nonlinear response is simulated using numerical integration of the Schrodinger equation with a Hamiltonian constructed to explicitly treat intermolecular coupling and nonadiabatic effects in the high...

Excess thermo acoustical parameters such as excess intermolecular free length (Lf), excess adiabatic compressibility (), excess free volume (Vf), excess enthalpy (H) have been measured for propylene glycol in Hexanol for various mole fractions at 303K temperature through ultrasonic sudy. These results have been explained on the basis of intermolecular interactions between the components in the...

The title compound, C(13)H(12)N(4)O, crystallizes with two independent mol-ecules in the asymmetric unit. The compound crystallizes as the ZE isomer, where Z and E refer to the configuration around the C=N and N-C bonds, respectively, with an N-H⋯N(py) (py is pyridine) intra-molecular hydrogen bond. The dihedral angles between the least-squares planes through the semicarbazone group and the pyr...

# 2006 International Union of Crystallography All rights reserved In the crystal structure of the title compound, C16H18N2O2, the indole moiety is nearly planar. The two carbonyl groups are almost perpendicular, with a torsion angle of 105.7 (4) , and the single C—C bond linking the two carbonyl groups is 1.515 (5) Å in length. The molecules are linked together by N—H O intermolecular hydrogen ...

In this work we present the synthesis and X-ray single crystal structural characterizat ion of the heterocyclic compound rac-N-acetyl-2-thiohydantoin-leucine. Th is material crystallize in the triclin ic system with space group P-1 (No2), Z=4, with two independent molecu les in the unit asymmetric. The crystal packing is governed by N--H···O hydrogen bond-type intermolecular interactions, formi...