2,2′-Di­propyl­malonic acid: intermolecular association via strong O—H...O hydrogen bonds

The molecular structure of the title compound, C₉H₁₆O₄, is described by a trans-planar configuration of the propyl chains. The mol­ecule has an approximate pseudo-twofold rotation axis in the crystal structure. The mol­ecules are interconnected by strong O—H...O hydrogen bonds and form an R₂²(8) ring structure.

2,2'-Diamino­dibenzyl: a rare case of crystallographically non-compliant mol­ecular symmetry

The title compound, C₁₄H₁₆N₂, adopts a trans-planar conformation. However, the mol­ecule, which possesses C_i point group symmetry, crystallizes in the non-centrosymmetric space group P2₁2₁2₁. In the crystal structure, the mol­ecular symmetry is only approximately retained. The crystal packing is predominantly stabilized by N—H...N hydrogen bonds. Weak C—H...π inter­actions also contribute to the stability.