Supramolecular interactions were studied in two planar model systems, 1,5and 2,6-dibromoanthraquinones, prepared on Au(111) using scanning tunneling microscopy. In both systems, we found rigid triangular structures that consisted of simultaneous halogen bonds and hydrogen bonds, as reported in protein-ligand complexes. We proposed molecular models that were well reproduced by first-principle st...

The crystal structure of the title compound, C(15)H(12)Cl(2)N(2)O(2), contains three intramolecular hydrogen bonds; two C-H⋯O and a nonclassical N-H⋯Cl. The structure is further stabilized by intermolecular N-H⋯O hydrogen bonds and C-H⋯π interactions, resulting in a three-dimensional network. The two benzene rings make an interplanar angle of 58.0 (1)°.

In the structure of DL-proline, C5H9NO2, the molecules are connected via classical intermolecular N-H...O hydrogen bonds involving the amine and carboxyl groups [N...O = 2.7129 (15) and 2.8392 (16) A], and form chains along the b-axis direction and parallel to (-101). The chains are linked into sheets via weak non-classical hydrogen bonds. The conformation of the molecule and its packing are no...

In the title complex, [Co(NCS)(2)(C(6)H(12)N(4))(CH(4)O)(2)(H(2)O)], the six-coordinated Co atom has a slightly distorted octa-hedral geometry. The molecules are linked by intermolecular O-H⋯S and O-H⋯N hydrogen bonds, forming a three- dimensional crystal structure. Intramolecular C-H⋯N and C-H⋯O hydrogen bonds are also present.

Alanine tripeptide is a good model molecule to analyze a conformational distribution of an unstructured peptide backbone, to study a competition between the intraand intermolecular hydrogen-bonding, as well as the favourable solvation conditions. In our work, we used three different spectroscopic techniques, the Raman and infrared (IR) spectroscopy, and the vibrational circular dichroism (VCD) ...

A hydrogen bond for a local-minimum-energy structure can be identified according to the definition of the International Union of Pure and Applied Chemistry (IUPAC recommendation 2011) or by finding a special bond critical point on the density map of the structure in the framework of the atoms-in-molecules theory. Nonetheless, a given structural conformation may be simply favored by electrostati...

Colorless crystals of l-alanine hydrochloride monohydrate, C(3)H(8)NO(2) (+)·Cl(-)·H(2)O, were obtained from a powder sample that had been left standing in a refrigerator for a few years. The structure displays several inter-molecular hydrogen bonds: the hydroxyl O atom is involved in a single hydrogen bond to the chloride anion, while the ammonium group forms one hydrogen bond to the chloride ...

The effect of pressure on the crystal structure of salicylaldoxime has been investigated. The ambient-pressure phase (salicylaldoxime-I) consists of pairs of molecules interacting through oximic OH...O hydrogen bonds; taken with phenolic OH...N intramolecular hydrogen bonds, these dimers form a pseudo-macrocycle bounded by an R4 4(10) motif. The dimers interact principally via pi...pi stacking ...

In the crystal of the title compound, C(11)H(12)O(4), inversion dimers arise from pairs of intermolecular O-H⋯O hydrogen bonds and C-H⋯O bonds further consolidate the packing. There is also a C-H⋯π contact between the benzene ring and the methyl-ene group.

The PACHA (Partial Atomic Charges and Hardnesses Analysis) formalism is applied to various supramolecular assemblies of water molecules. After a detailed study of all available crystal structures for ice polymorphs, we shown that the hydrogen bond strength is roughly constant below 1 GPa and considerably weakened above that value. New hydrogen bond patterns are proposed for ice IV, V, and VI af...