In the title racemic compound, C(26)H(32)N(2)O(3), an intra-molecular O-H⋯N hydrogen bond is formed between the phenolic OH group and the tertiary amine N atom. Another O-H⋯N hydrogen bond that is formed between the OH group and the pyridine N atom links the mol-ecules into a polymeric chain extending along the a axis. The structure is further stabilized by intramolecular and intermolecular C-H...

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) ...

At 150 K, the title compound, C(9)H(11)NO(4)S, crystallizes in the orthorhombic form as a zwitterion and has a low gauche conformation [chi = -46.23 (16) degrees] for an acyclic cysteine derivative. A difference in bond length is observed for the alkyl C-S bond [1.8299 (15) A] and the aryl C-S bond [1.7760 (15) A]. The -NH(3)(+) group is involved in four hydrogen bonds, two of which are intermo...

Intermolecular hydrogen bonds of the type N–H...N in crystals of imidazole and its 4-substituted and 4,5-disubstituted derivatives were studied by N CP/MAS NMR and an ab initio molecular orbital (MO) calculation. In the N CP/MAS NMR spectrum of each of the imidazole derivatives, two peaks due to the two different functional groups, >NH and =N-, were observed. The value of the N isotropic chemic...

We report a real-space visualization of the formation of hydrogen bonding in 8-hydroxyquinoline (8-hq) molecular assemblies on a Cu(111) substrate, using noncontact atomic force microscopy (NC-AFM). The atomically resolved molecular structures enable a precise determination of the characteristics of hydrogen bonding networks, including the bonding sites, orientations, and lengths. The observati...

Infrared-ultraviolet double resonance spectroscopy has been applied to study the infrared spectra of the supersonically cooled gas phase complexes of formic acid, acetic acid, propionic acid, formamide, and water with 9-hydroxy-9-fluorenecarboxylic acid (9HFCA), an analog of glycolic acid. In these complexes each binding partner to 9HFCA can function as both proton donor and acceptor. Relative ...

A combined experimental and theoretical study of one oxaphosphinane derivative was made on the basis of a topological analysis of its electron density distributions. The electron density was determined from a high-resolution X-ray diffraction data set measured with synchrotron radiation at 100 K, whereas theoretical calculations were performed using density functional theory (DFT) methods at th...

In the crystal structure of the title compound C(15)H(27)N(3)O(4), the mol-ecule is located on a twofold axis and the asymmetric unit contains one half-mol-ecule, with one N and one C atom lying on the rotation axis. The pyridine ring is the hydrogen-bond acceptor, while two hydroxyl O atoms act as hydrogen-bond donors in intra-molecular O-H⋯N and intermolecular O-H⋯N and O-H⋯O hydrogen bonds, ...

The title compound, C(16)H(16)N(2)O, which contains a double bond connecting an azabicyclic ring system to an indol-3-ylmethylene group, crystallizes from a solution in ethyl acetate. The geometries of the two crystallographically independent molecules are nearly identical. The crystal packing of the title compound involves two types of intermolecular hydrogen bond.

Ab initio and density functional theory (DFT) calculations on some model systems are presented to assess the extent to which intermolecular hydrogen bonding can affect the planarity of amide groups. Formamide and urea are examined as archetypes of planar and non-planar amides, respectively. DFT optimisations suggest that appropriately disposed hydrogen-bond donor or acceptor molecules can induc...