2-Sulfanyl-idene-1,2-dihydro-pyridine-3-carbohydrazide.

All non-H atoms of the title compound, C(6)H(7)N(3)OS, which exists in the thione form, lie in a common plane (r.m.s. of non-H atoms = 0.08 Å). The amino group of the -NH-NH(2) substituent forms an intra-molecular hydrogen bond to the S atom. The terminal -NH(2) group is pyramidally coordinated; it forms a weak N-H⋯O and a weak N-H⋯S hydrogen bond. Furthermore, the N atom is an acceptor for a C-H⋯N contact. The amino group of the ring is a hydrogen-bond donor to the carbonyl O atom of an adjacent mol-ecule, this inter-action giving rise to a linear chain motif running along the b axis.

N-(2-Hydroxy-phen-yl)-4-nitro-phthalimide.

Mol-ecules of the title compound, C(14)H(8)N(2)O(5), are linked by a hydr-oxy-amide O-H⋯O hydrogen bond into a linear chain. The hydr-oxy group is disordered over two positions of the benzene ring in an approximate 0.57:0.43 ratio.

2-(3,5-Di-tert-butyl-4-hydroxy-benzyl-sulfan-yl)nicotinic acid.

Two mol-ecules of the title compound, C(21)H(27)NO(3)S, are disposed about a center of inversion, generating an O-H⋯O hydrogen-bonded dimer.

Di-n-butyl-ammonium 2-(3,5-di-tert-butyl-4-hydroxy-benzyl-sulfan-yl)nicotinate.

The asymmetric unit of the title compound, C(8)H(20)N(+)·C(21)H(26)NO(3)S(-), contains two indpendent ion pairs which are disposed about a psuedo-inversion center, generating an ammonium-carboxylate N-H⋯O hydrogen-bonded four-component cluster. In the crystal structure, adjacent clusters are linked by hydr-oxy-carboxylate O-H⋯O hydrogen bonds, forming a chain.