2,2′-(1,4-Phenyl­enedivinyl­ene)diquinolin-8-ol

The title compound, C₂₈H₂₀N₂O₂, has a crystallographic inversion centre, and an intra­molecular O—H...N hydrogen bond may have an effect on some bond lengths and angles.

3,6-Bis(4-methoxy­benz­yloxy)pyridazine

In the crystal structure of the title compound, C₂₀H₂₀N₂O₄, the mol­ecules are linked by a weak inter­molecular C—H...N hydrogen bond. The molecule has crystallographic twofold rotation symmetry.

1-[4-(4-Methyl­pyrimidin-2-yl)piperazin-1-ylmeth­yl]-1H-benzotriazole

The title compound, C₁₆H₁₉N₇, is a potent new herbicide. X-ray analysis reveals that the piperazine ring adopts a chair conformation and weak C—H...N hydrogen bonds link the mol­ecules into a chain along the a axis.

3-(2-Chloro­phen­yl)-N-(2-cyano-4-meth­yl-2-pent­yl)-5-methyl­isoxazole-4-carboxamide

The title compound, C₁₈H₂₀ClN₃O₂, is a potent new herbicide. X-ray analysis reveals that the benzene ring is twisted away from the isoxazole ring by 67.7 (1)°. The crystal packing is stabilized by inter­molecular N—H...N and C—H...O hydrogen bonds.