Zaharah Aiyub

N-(Pyrazin-2-yl)aniline.

The two aromatic rings in the title compound, C10H9N3, are inclined at 15.2 (1)° to each other; this opens up the angle at the amino N atom to 130.4 (1)°. The amino N atom forms a hydrogen bond to the 4-N atom of an adjacent molecule to create a chain motif.

Structural Studies of Potassium Hexatitanates Prepared under Hydrothermal and Solid State Conditions

The structural studies of potassium hexatitanates prepared under both hydrothermal and solid state conditions were carried out. Fourier Transform Infra-red spectroscopy (FTIR) results revealed that potassium hexatitanate structure consisted of TiO6 octahedral units irrespective of the preparative conditions and particle size. X-ray diffraction (XRD) results showed that the only potassium hexatitanate phase was detectable and the structure is of the Wadsley-type consisting of chains of Ti-O octahedral sharing edges with tunnels in which the potassium ions are located. From scanning electron microscopy (SEM) results, the different preparative conditions resulted in different particle sizes and morphologies of the potassium hexatitanate formed.

Tetra-μ-acetato-κ8O:O′-bis­{[4-methyl-N-(4-methyl­phen­yl)pyridin-2-amine-κN1]copper(II)}

The title complex, [Cu2(CH3COO)4(C13H14N2)2], features a binuclear molecule, which lies about a crystallographic centre of inversion; the four acetate ions each bridge a pair of CuII atoms. The coordination of the metal atom is distorted octahedral within a donor set defined by four O atoms, the heterocyclic N atom and the second Cu atom. The pyridine ring is twisted with respect to the tolyl ring and forms a dihedral angle of 35.34 (9)°. A bifurcated N—H⋯(O,O) hydrogen bond is present, linking the amine group to two carboxylate O atoms derived from different acetate ions. In the crystal, C—H⋯π interactions link molecules into a supramolecular array in the bc plane.

N-(2-Pyrid-yl)-4-toluidine.

There are two molecules in the asymmetric unit of the title compound, C12H12N2, with dihedral angles between the aromatic rings of 48.35 (12) and 51.02 (12)°. In the crystal structure, both molecules form inversion dimers, linked by pairs of N—H⋯N hydrogen bonds.

N-(Pyrazin-2-yl)-4-toluidine

The two aromatic systems in the title compound, C11H11N3, are inclined by 19.1 (1)°, whilst the angle at the central amino N atom is 130.3 (2)°. The amino group forms a hydrogen bond to the pyrazine N-4 atom of an adjacent molecule, forming a chain motif.

2-(4-Chloro­anilino)pyridine

The two aromatic rings of each of the four independent molecules in the asymmetric unit of the title compound, C11H9ClN2, are approximately coplanar; the four molecules are arranged into two amino–pyridyl N—H⋯N hydrogen-bonded pairs. The structure has a 15% twin component related by a twofold rotation about [100].

N-(4-Methyl-2-pyrid-yl)-p-toluidine.

In the title compound, C13H14N2, the dihedral angle between the aromatic rings is 48.1 (1)° and the bridging C—N—C bond angle is 127.24 (12)°. In the crystal, intermolecular N—H⋯N hydrogen bonding about a center of inversion generates a hydrogen-bonded dimer.

Tetra-μ-acetato-κ8O:O′-bis­{[4-methyl-2-(m-tolyl­amino)pyridine-κN]copper(II)}

In the crystal structure of the title binuclear complex, [Cu2(CH3COO)4(C13H14N2)2], the four acetate groups each bridge a pair of CuII atoms. The coordination of the metal atoms is distorted square-pyramidal, with the bonding O atoms comprising a square basal plane and the coordinating N atom of the N-heterocycle occupying the apical position. In the two N-hetercycle ligands, the benzene rings are twisted with respect to the pyridine rings, making dihedral angles of 53.1 (2) and 54.2 (2)°. Intramolecular N—H⋯O hydrogen bonding is present between the imino and carboxy groups. The crystal studied was a non-merohedral twin with a minor twin component of 21.4%.

N-(Pyrimidin-2-yl)aniline

There are two molecules in the asymmetric unit of the title compound, C10H9N3, with inter-ring dihedral angles of 31.1 (1) and 35.3 (1)°. The bridging C—N—C bond angles are 128.2 (1) and 129.1 (1)°. In the crystal, the two independent molecules are linked into a dimer by two N—H⋯N hydrogen bonds.

4-Methyl-N-(3-methyl­phen­yl)pyridin-2-amine

The title amine, C13H14N2, is twisted with a dihedral angle between the rings of 60.07 (9)°. The amine N—H group and pyridine N atom are syn allowing for the formation of centrosymmetric eight-membered {⋯HNCN}2 synthons via N—H⋯N hydrogen bonds. The two-molecule aggregates are sustained in the three-dimensional crystal packing via C—H⋯π and π–π interactions [centroid–centroid distance for pyridyl rings = 3.7535 (12) Å]