In the title compound, C(10)H(12)O(4)·H(2)O, the 2,4,5-trimeth-oxy-benzaldehyde mol-ecule is almost planar (rms deviation = 0.0183 Å). There is an R(1) (2)(5) ring motif due to O-H⋯O hydrogen bonding. In the crystal, the mol-ecules are stabilized in the form of one-dimensional polymeric chains extending along [010] due to O-H⋯O hydrogen bonding with adjacent water mol-ecules. The H atoms involv...

The inverse Raman spectrum of bilirubin and bilirubin ditauride were measured under pre-resonant conditions. Spectra in chloroform and dimethyl sulfoxide were assigned by comparison with model compounds and on the basis of the known effects of the solvents on the internal hydrogen bonding in bilirubin. The band assignments were used to interpret the spectra of bilirubin ditauride in aqueous sol...

The influence of hydrogen bonding (HB) and protonation on an intramolecular charge transfer (ICT) compound, such as N,N-dimethyl-4-(phenylimino-methyl)-aniline (NMe2-4PmA) in the ground and excited state with two protic solvents 2,2,2-trifluoroethanol (TFE) and 2,2,2-trichloroethanol (TCE) is investigated. Mono HB and mono protonation complexes with TFE and TCE both in the ground state as well ...

The title half-sandwich rhodium(III) complex, [Rh(C10H15)(C7H7O3S)2(H2O)]·H2O, consists of a π-bonded penta-methyl-cyclo-penta-dienyl group, two σ-bonded tosyl-ate groups and an aqua ligand. The structure displays both inter- and intra-molecular O-H⋯O hydrogen bonding. The inter-molecular hydrogen bonding results in an extended helical chain along a 21 screw axis parallel to c, due to hydrogen ...

In the crystal structure of TBM-trihydrate three waters of crystallization were found to locate dissymmetrically. Thus, one of them forms a chelated ring with the neighboring C=O and N-H of TBM. Two other ones bind each other through hydrogen bonding and two sets of which form a cyclic dimer by hydrogen bonding (namely, water-tetramer). A C=O group binds by hydrogen bonding to each of the tetra...

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...

Arzanol is a naturally-occurring prenylated acylphloroglucinol isolated from Helichrysum italicum and exhibiting anti-oxidant, antibiotic and antiviral activities. The molecule contains an α-pyrone moiety attached to the phloroglucinol moiety through a methylene bridge. The presence of several hydrogen bond donor or acceptor sites makes intramolecular hydrogen bonding patterns the dominant stab...

Formation of C–H H–B dihydrogen bonded complexes of acetylene, fluoroacetylene, chloroacetylene, and cyanoacetylene with borane-trimethylamine were investigated with MP2 and B3LYP methods using 6-311++G(d,p) and aug-cc-pVDZ basis sets. The stabilization energies ranged from 6–20 kJ mol . NBO analysis predicts transfer of charge from r B–H bonding orbital to r* C–H anti-bonding orbital. It was a...

Four halogen and hydrogen bonding rotaxane host systems featuring pyridinium bis-amide-iodotriazole/prototriazole and pyridinium bis-amide-iodotriazolium/prototriazolium axle components have been synthesized by CuAAC-mediated mono-stoppering chloride anion templation and post-rotaxanation methylation reactions. In competitive 45 : 45 : 10 CDCl3-CD3OD-D2O aqueous solvent media, the dicationic ha...

The crystal structure of the title salt, C8H12N(+)·C4H3O4 (-), consists of a 2,5-di-methyl-anilinium cation and an hydrogen maleate anion. In the anion, a strong intra-molecular O-H⋯O hydrogen bond is observed, leading to an S(7) graph-set motif. In the crystal, the cations and anions pack in alternating layers parallel to (001). The ammonium group undergoes inter-molecular N-H⋯O hydrogen-bondi...