Crystal structure of a second monoclinic polymorph of 3-methoxybenzoic acid with Z′ = 1

Abstract

A new polymorphic form of the title compound, C8H8O3, is described in the centrosymmetric monoclinic space group P21/c with Z′ = 1 as compared to the first polymorph, which crystallizes with two conformers (Z′ = 2) in the asymmetric unit in the same space group. In the crystal of the second polymorph, inversion dimers linked by O—H...O hydrogen bonds occur and these are linked into zigzag chains, propagating along the b-axis direction by C—H...O links. The crystal structure also features a weak π–π interaction, with a centroid-to-centroid distance of 3.8018 (6) Å. The second polymorph of the title compound is less stable than the reported first polymorph, as indicated by its smaller calculated lattice energy.

Keywords

• crystal structure
• polymorph
• hydrogen-bond
• 3-methoxybenzoic acid