2-Cyano-3-(4-hydroxy­phenyl)­propenoic acid

The title compound, C₁₀H₇NO₃, has the cyano, carboxyl­ic acid and phenol groups in a trans configuration with respect to the C=C double bond. Intramolecular O—H...N and eight-membered O—H...O hydrogen-bonding interactions form an infinite two-dimensional layer structure.

trans-1,2-Bis(4-pyrid­yl)ethyl­ene monohydrate

In the title compound, C₁₂H₁₀N₂·H₂O, inter­molecular O—H...N hydrogen bonds are highly effective in forming a one-dimensional chain. In addition, the presence of C—H...O hydrogen bonds helps to build a three-dimensional supramolecular network, thereby stabilizing the crystal structure.