Benzyl ether protected polyhydroxylated alkene compounds containing allylic alcohol, ether or ester functionality undergo a stereospecific cyclisation reaction upon treatment with TFA-acetonitrile-toluene with inversion of configuration at the allylic position and loss of a benzyl ether to give tetrahydrofurans.

The title compound, C(15)H(13)N(3)O(4), was synthesized by the reaction of equimolar quanti-ties of 2-methoxy-benzaldehyde and 2-nitro-benzohydrazide in methanol. The dihedral angle between the two substituted benzene rings is 68.3 (2)°. In the crystal structure, inversion dimers linked by pairs of N-H⋯O hydrogen bonds occur.

The title compound, C28H40N2, was obtained from the condensation reaction of 4-tert-butyl-2,6-di-methyl-aniline and butane-2,3-dione. The mol-ecule lies on an inversion centre. The C=N bond has an E conformation. The plane of the benzene ring is almost perpendicular to the 1,4-di-aza-butadiene mean plane [dihedral angle = 89.8 (9)°].

The title compound, C21H26N4S, was synthesized by the condensation reaction of 4-iso-propyl-benzaldehyde with thio-carbohydrazide in ethanol. The planes of the two benzene rings in the mol-ecule are inclined at 22.6 (1)°. In the crystal, pairs of inter-molecular N-H⋯S hydrogen bonds link the mol-ecules into inversion dimers.

The title compound, P(C10H7)3·0.5CHCl3, was isolated after the unsuccessful reaction of KSeCN and tris-(naphthalen-1-yl)phosphane. The solvent mol-ecule is disordered about an inversion center. The effective cone angle of the phosphine is 203°. In the crystal, weak C-H⋯Cl and C-H⋯π inter-actions are observed.

The title compound, C(10)H(11)N(3)O(3), was prepared by the reaction of acetohydrazide and 1-(4-nitro-phen-yl)ethanone. The asymmetric unit contains two crystallographically independent mol-ecules. Inversion-related mol-ecules form dimers, in which two N-H⋯O hydrogen bonds generate an inter-molecular R(2) (2)(8) ring.

Reaction of nickel(II) chloride with sodium dicyanamide and pyridazine leads to single crystals of the title compound, [Ni{N(CN)(2)}(2)(C(4)H(4)N(2))(4)], in which the Ni(II) cation is octa-hedrally coordinated by two dicyanamide anions and four pyridazine ligands into a discrete complex that is located on a center of inversion.

The title compound, C(12)H(17)N(3)S, was prepared by the reaction of 4-ethyl-thio-semicarbazide and 3,4-dimethyl-benzaldehyde. The dihedral angle between the thiourea unit and the benzene ring is 7.09 (8)°. In the crystal, inversion dimers linked by pairs of N-H⋯S hydrogen bonds occur.

In the title compound, C(10)H(13)NO(2), synthesized by the reaction of 2-hy-droxy-3-eth-oxy-benzaldehyde with methyl-amine, there is an an intra-molecular O-H⋯N hydrogen bond involving the hy-droxy substituent and the amino N atom. In the crystal, mol-ecules form inversion dimers connected by pairs of C-H⋯O hydrogen bonds.

The reaction between benzyl-triethyl-ammonium chloride and dimethyl-tin dichloride yields the title salt, [(C(6)H(5)CH(2))(C(2)H(5))(3)N](2)[SnCl(6)]. The Sn(IV) atom, located on a center of inversion, exists in an octa-hedral coordination environment. The cation links with the anion via weak C-H⋯Cl hydrogen bonding.