The title compound, C(11)H(13)N(3)O, is a derivative of the anti-tuberculosis drug isoniazid [systematic name: pyridine-4-carbohydrazide]. The crystal structure consists of repeating hydrogen-bonded chains parallel to the b axis. Adjacent mol-ecules in the chains are linked by bifurcated N-H⋯(O,N) hydrogen bonds, which form an R(1) (2)(5) ring motif.

The title mol-ecule, C(16)H(24)O(8)S, is a dihydro-agrofuran derivative and has a heteropolycyclic structure. One cyclohexane ring exhibits a chair conformation and the other a non-chair conformation. In the crystal structure there is an inter-molecular C-H⋯O hydrogen-bonding inter-action to stabilize the packing.

In the title benzoyl-hydrazide derivative, C15H14N2O2, the dihedral angle between the planes of the two phenyl rings is 12.56 (9)°. The azomethine double bond adopts an E configuration stabilized by an N-H⋯O hydrogen bond. In the crystal, the components are linked by C-H⋯O inter-actions to form chains along the b axis.

The title compound, C(16)H(12)O(5)S, is a derivative of coumarin. The dihedral angle between the coumarin ring system and the phenyl ring is 65.9 (1)°. In the crystal structure, mol-ecules are linked by weak C-H⋯O hydrogen bonding to form molecular ribbons.

The nine-membered fused-ring system of the title pyridazine derivative, C(7)H(7)N(3)OS, is almost planar (r.m.s. deviation 0.012 Å). In the crystal, the amino H atom forms a hydrogen bond to the ketonic O atom of a neighboring mol-ecule to generate a centrosymmetric dimer.

The chiral title compound, C(7)H(12)O(2), a lactone derivative, features a seven-membered ring that adopts a chair conformation. The crystal structure is stabilized by weak C-H⋯O inter-actions occurring in the (100) plane. The absolute configuration was assigned on the basis of the enantioselective synthesis.

In the title boron-dipyrromethene derivative, C17H16BF2N3, the benzene ring and the boron-dipyrromethene mean plane form a dihedral angle of 55.82 (8)°. In the crystal, pairs of C-H⋯F inter-actions link the mol-ecules, forming inversion dimers. Further C-H⋯F inter-actions link the dimers into a three-dimensional network.

The half-sandwich tamoxifen derivative, Mn(CO)(3)(η(5)-C(5)H(4)(Et)C=C(C(6)H(5))(2)), gives a radical cation which is charge-delocalized between the "cymantrenyl" and diphenylethene moieties and undergoes facile metal-carbonyl substitution reactions. Mn and Re complexes with finely tuned redox potentials can be obtained for cancer cell inhibition studies.

In the title sulfonamide derivative, C(14)H(13)F(2)NO(4)S, the dihedral angle between the benzene rings is 66.05 (9)°. The crystal structure is stabilized by weak inter-molecular N-H⋯O hydrogen bonds involving the amine and meth-oxy groups, which link the mol-ecules into a one-dimensional chain. No significant inter-chain contacts are observed.

In the title compound, C(18)H(40)N(2)O(2)S(2), a vicinal diamine derivative, the crystal structure is stabilized by two intra-molecular N-H⋯O hydrogen bonds. The distance between the two kernel chiral C atoms is 1.580 (2) Å.