A family of closely related zinc porphyrin-pyridine complexes were used to examine the influence of linker preorganization on supramolecular effective molarities for formation of intramolecular H-bonds. Each pyridine ligand was equipped with a side-chain containing two H-bond acceptors, one on the end of the chain (terminal) and one in the middle of the chain (linker). These H-bond acceptors ma...

Three N-substituted 5-chlorosalicylamides (4-chlorophenyl, 2a; benzyl, 2b; phenethyl 2c) differing in the length of the 'linker' between the benzene ring and the amide moiety were prepared in order to compare their supramolecular architecture. The intramolecular NH··O(H) hydrogen bond and the intermolecular C=O··H–O hydrogen bond were found in the crystal structure of 2a and 2c thus forming an ...

In the title salt, C(9)H(12)NO(2) (+)·NO(3) (-), the cation and anion are linked by a bifurcated N-H⋯(O,O) hydrogen bond. The crystal packing is stabilized by inter-molecular N-H⋯O, O-H⋯O and C-H⋯O hydrogen bonds, which connect neighbouring cations and anions, resulting in a two-dimensional network.

In the title compound, C(15)H(13)NO(4)·H(2)O, the Schiff base exists in a zwitterionic form and a bifurcated intra-molecular N-H⋯(O,O) hydrogen bond generates two S(6) rings. The dihedral angle between the two benzene rings is 25.8 (2)°. The crystal structure is stabilized by inter-molecular O-H⋯O hydrogen bonds.

In the crystal structure of the title compound, C(16)H(14)O(6)·H(2)O, the dihedral angle between the benzene rings is 60.8 (3)°. Mol-ecules are linked through a bifurcated O-H⋯O hydrogen bond, forming a zigzag chain along the b axis. The chains are further linked by O-H⋯O hydrogen bonds mediated by water mol-ecules.

In the title compound, C(18)H(19)FN(2)O, the hydrazide side chain is approximately perpendicular to the central ring [dihedral angle = 76.80 (5)°]. The F atom is disordered over two positions with occupancies of 0.818 (2) and 0.182 (2). The packing consists of chains of mol-ecules parallel to the a axis, connected by a bifurcated N-H⋯(O,N) hydrogen bond and a weak C(phen-yl)-H⋯O hydrogen bond. ...

Molecular structure, isomerism, conformational stability and intramolecular hydrogen bonding (IHB) of cis-enol forms of 1-(n-pyridyl)butane-1,3-diones (nPBD) (n = 2, 3, or 4) have been investigated by means of density functional theory (DFT) calculations. Energy differences for all possible nPBD cis-enol forms of isomers with respect to the most stable form of the correspondin...

The title compound, C(16)H(16)ClNO(3), is a Schiff base displaying a trans configuration of the C=N double bond. In the crystal structure, inter-molecular C-H⋯N and bifurcated C-H⋯(O,O) hydrogen bonds are observed.

In the the title compound, C(6)H(5)BrN(2)O, an intra-molecular N-H⋯N hydrogen bond generates an S(5) ring. In the crystal structure, inter-molecular bifurcated N-H⋯(O,O) hydrogen bonds link the mol-ecules, leading to sheets propagating in (100).