Crystal structure of a second polymorph of tetrakis(pyridin-2-yl)methane

A second polymorph of the title compound, C 21 H 16 N 4 , is reported. The original polymorph was solved by our group [Matsumoto et al. (2003). Tetrahedron Lett. 44 , 2861–2864] in the monoclinic space group C 2/ c and refined to R = 0.050. Now the crystal structure of a tetragonal polymorph (space group P -42 1 c ) has been solved and refined to R = 0.036. In the crystal, there are no strong intermolecular interactions. Reflecting the high symmetry of the molecular structure, the asymmetric unit is a quarter of the molecule, and the molecule exhibits S 4 symmetry along the c axis in the crystal.