N-(4-Meth­oxy­benz­yl)phthalimide: a triclinic polymorph

The title compound [systematic name: 2-(4-meth­oxy­benz­yl)­isoindoline-1,3-dione], C(16)H(13)NO(3), represents a triclinic polymorph of the previously reported monoclinic form [Warzecha et al. (2006 ▶). Acta Cryst. E62, o5450–o5452]. The reaction of potassium phthalimide and 4-meth­oxy­benzyl chloride in dimethyl­formamide gave platelet-shaped crystals; these were harvested and then needle-shaped crystals were deposited. The platelet- and needle-shaped crystals correspond to the triclinic and monoclinic forms, respectively. The N—C—C(ar)—C(ar) torsion angles between the ring systems are −82.66 (14) and 95.28 (13)°, resulting in a roof-shaped conformation. In the crystal, mol­ecules are accumulated by offset face–face π–π inter­actions between phthalimide units [centroid–centroid distances = 3.640 (2) and 3.651 (2) Å], with inter­planar distances of 3.321 (1) and 3.435 (1) Å. Weak inter­molecular C(ar­yl)—H⋯O=C and C(alk­yl)—H⋯O=C contacts form C(8) and C(11) infinite chain motifs, respectively.