3,6,13,16-tetrabromo-2,7,12,17-tetrapropylporphycene

The title compound [systematic name: 3,10,13,20-tetrabromo-4,9,14,19-tetrapropyl-21,22,23,24-tetraazapentacyclo[16.2.1.- 1(2,5).1(8,11).1(12,15)]tetracosa-2(22),3,5,7,9,11,13,15(24),16,18,20-undecaene], C32H34Br4N4, crystallizes in two distinct crystalline forms, viz. monoclinic prisms and triclinic plates, and the first of these is described here. The molecule of the prismatic form has a centre of symmetry and a more warped structure than that of the triclinic plate-like form. The shape of the central N-4 cavity is rectanglar, enlarged in the direction of the methine-bridge C atoms, and the N ... N distances are 2.713 (3) and 2.818 (3) Angstrom.