In the title compound, C(6)H(5)IO(3)S·C(4)H(9)NO·H(2)O, N,N-dimethylacetamide and 4-iodobenzenesulfonic acidmolecules are linked by an intramolecular C-H⋯O hydrogen bond. In the crystal structure, inter-molecular O-H⋯O, O-H⋯I and C-H⋯O hydrogen bonds link the mol-ecules.

A theoretical study of the peri interactions, both intramolecular hydrogen (HB) and chalcogen bonds (YB), in 1-hydroxy-8YH-naphthalene, 1,4-dihydroxy-5,8-di-YH-naphthalene, and 1,5-dihydroxy-4,8-di-YH-naphthalene, with Y = O, S, and Se was carried out. The systems with a OH:Y hydrogen bond are the most stable ones followed by those with a chalcogen O:Y interaction, those with a YH:O hydrogen bo...

In the title compound, C(11)H(10)ClNO(3), the dihedral angle between the benzene ring and the amide group is 6.6 (10)° and an intramolecular O-H⋯O hydrogen bond occurs. In the crystal, molecules are linked by N-H⋯O hydrogen bonds, generating C(7) zigzag chains.

The title compound, C(12)H(21)NO(4), a γ-aminobutyric acid derivative, crystallizes with two mol-ecules in the asymmetric unit. The crystal structure is stabilized by inter-molecular N-H⋯O and O-H⋯O hydrogen bonds, forming a strand. An intramolecular N-H⋯O hydrogen bond is also observed.

Approximate ab initio molecular orbital methods are used to examine the structural and electronic properties of oxymorphone. The most stable conformation of the molecule is found to include an intramolecular hydrogen bond between the C-14 hydroxyl group and the nitrogen atom in agreement with available experimental data. The total molecular electron density is transformed to a set of localized ...

In mol-ecule of the title compound, C(16)H(14)N(2)O(2), the two aromatic rings form a dihedral angle of 6.93 (3)° and an intramolecular N-H⋯O hydrogen bond occurs. In the crystal structure, inter-molecular O-H⋯O hydrogen bonds link the mol-ecules into zigzag chains running in the [10] direction.

The title compound, C(7)H(4)Cl(2)O(2), exhibits a layer crystal structure; mol-ecules within each layer are linked by weak C-H⋯O inter-molecular hydrogen bonds. There is also an intramolecular O-H⋯O hydrogen bond.

The conformational stability of hexahydropyridobenzodioxin and related derivatives in both protonated and non-protonated forms have been investigated by means of ab initio molecular orbital methods as well as semi-empirical AM1 and PM3 methods. One of the cis conformers (cis2e) has been found to be most stable due to the formation of an intramolecular hydrogen bond, other conformers including t...

The vicinity of a hydrogen bond donor (O–H) and a hydrogen bond acceptor (C=O or C=N– R) in salicylaldehydes and ortho-Schiff bases results in significant structural variations compared to the monosubstituted derivatives that are reflected in the electronic structure and thus in the spectroscopic properties. This interplay between intramolecular hydrogen bonding and multicenter πelectron deloca...

In the title compound, C(16)H(15)ClN(2)O(3)·H(2)O, the water mol-ecule is linked to the Schiff base mol-ecule via an O-H⋯O hydrogen bond. In the Schiff base mol-ecule, an intramolecular O-H⋯N hydrogen bond occurs and the dihedral angle between the two benzene rings is 20.5 (5)°. In the crystal, the Schiff base and water mol-ecules are linked by inter-molecular N-H⋯O and O-H⋯O hydrogen bonds, fo...