Second monoclinic polymorph of 4-[(1H-benzimidazol-1-yl)methyl]benzoic acid

Recently, we reported the first monoclinic [Kuai & Cheng (2011). Acta Cryst., E67, o2787] and the orthorhombic polymorph [Kuai & Cheng (2011). Acta Cryst., E67, o3014] of the title compound, C(15)H(12)N(2)O(2). Another monoclinic polymorph was obtained accidentally by the hydrothermal reaction of the title compound with manganese chloride in the presence of potassium hydroxide at 413 K. The asymmetric unit consists of four independent molecules. In the crystal, O-H center dot center dot center dot N hydrogen bonds link the independent molecules into four separate chains parallel to the b axis.