In response to external stimuli the α-d-glucose molecule extensively transforms its H-bonding pattern and conformation. High-pressure reverses the linear compressibility and changes the hierarchy of intermolecular interactions in crystalline α-d-glucose. At 5.40(2) GPa it undergoes an isostructural phase transition rearranging the OH···O hydrogen bonds, promoting the role of CH···O contacts and...

In the title compound, C(20)H(17)ClN(4)O(2)S, the dihedral angle between the two benzene rings is 65.9 (1)°; the corresponding angle between the 4-chloro-phenyl and thia-diazole rings is 3.4 (8)°. The conformations of the N-H and C=O bonds are anti with respect to each other. The enone groups show a trans configuration. The structure displays intermolecular N-H⋯O, C-H⋯N, C-H⋯S and C-H⋯O hydroge...

A new method based on absolutely localized molecular orbitals (ALMOs) is proposed to measure the degree of intermolecular electron density delocalization (charge transfer) in molecular complexes. ALMO charge transfer analysis (CTA) enables separation of the forward and backward charge transfer components for each pair of molecules in the system. The key feature of ALMO CTA is that all charge tr...

The title compound, C(18)H(15)NO, is a Schiff base prepared from an acid-catalyzed condensation reaction between 1-naphthaldehyde and 6-amino-m-cresol. Intra-molecular hydrogen bonding occurs via an O-H⋯N inter-action, generating an S(5) ring motif. Neighboring phenol groups participate in inter-molecular hydrogen bonding through an O-H⋯O inter-action, forming chains. The O atom of the phenol g...

The infrared spectra of CH3Cl + H2O isolated in solid neon at low temperatures have been investigated. The CH3Cl + H2O system is remarkable because of its propensity to form CH3Cl:H2O and CH3Cl:(H2O)n (n > or = 2) complexes. We focus here on the CH3Cl:H2O species. Low concentration studies (0.01-0.5%) and subsequent annealing lead to formation of the 1:1 CH3Cl:H2O complex with O-H. . .Cl-C or O...

Vibrational spectroscopy with inelastic neutron scattering can provide spectra that are more detailed and easier to interpret than optical spectra. The spectral intensity depends on energy transfer and kinetic momentum transfer, allowing determination of the potential function. Experiments reveal that the proton involved in intermolecular hydrogen bonding in N-methylacetamide and polyglycine I ...

Benchmark quality structures and interaction energies have been produced using explicitly correlated coupled cluster methods for a systematic series of hydrogen and halogen bonded complexes: B···HCCH, B···HCl and B···ClF, with six different Lewis bases B. Excellent agreement with experimental structures is observed, verifying the method used to deduce the equilibrium deviation from collinearity...

In this study Klason lignins from Eucalyptus grandis (LEUG) and Pinus taeda (LPIT) were characterized using Fourier transform infrared (FTIR) spectroscopy and thermogravimetry (TGA). The degradation kinetic parameters were determined by TGA using the Kissinger method. Thermogravimetric results showed that LPIT had higher thermal stability and also higher activation energy than LEUG. FTIR result...

The title compound, C(13)H(18)N(2)O(4), crystallizes as discrete mol-ecules associated as N-H⋯O hydrogen-bonded dimers disposed about a crystallographic inversion centre. The structure is the first solid-state structure for a 3-acetyl-pyridone without C-4 to C-6 substituents. The amide subsituent at C-3 is coplanar with the pyridone ring, while the tert-butyl ester group is orthogonal to the py...

A novel class of stereocomplexes is described by the interaction of helically complementary poly(phenylacetylene)s (PPAs) carrying an α-methoxy-α-trifluoromethylphenylacetamide pendant group. The formation of the stereocomplex requires the presence of cis amide bonds on the external crest of the polymer to provide efficient cooperative supramolecular hydrogen bonding between matching enantiomer...