A triclinic polymorph of benzanilide: disordered molecules form hydrogen-bonded chains.

In the P-1 polymorph of benzanilide or N-phenylbenzamide, C(13)H(11)NO, the molecules are linked into simple C(4) chains by N-H...O hydrogen bonds. The molecules exhibit orientational disorder, but the donor and acceptor in a given hydrogen bond may occur, independently, in either the major or the minor orientation, such that all four possible N-H.O combinations have very similar geometries. The structure of this P-1 polymorph can be related to that of a previously reported C2/c polymorph.