A novel class of naturally occurring halogenated pyrroles, 1,1′-dimethyl-3,3′,4,4′,5,5′-hexabromo-2,2′-bipyrrole, 5,5′-dichloro-1,1′-dimethyl-3,3′,4,4′-tetrabromo-2,2′-bipyrrole, and 1,1′-dimethyl-3,3′,4,4′,5,5′-hexachloro-2,2′-bipyrrole

Crystal structure determinations of the three title hexahalogenated bipyrroles, (I) C10H6Br6N2, (II) C10H6Br4Cl2N2, and (III) C10H6Cl6N2, reveal essentially planar pyrrole rings having dihedral angles of 64.7, 65.1, and 64.2degrees between the least-squares planes, favoring in each case a closer methyl-halogen conformation. All three complexes crystallize in the orthorhombic space group Pbcn with the following cell dimensions: (I) a = 12.654(3) Angstrom, b = 8.853(2) Angstrom, c = 13.753(3) Angstrom, alpha = beta = gamma = 90degrees, Z = 4; (II) a = 12.438(6) Angstrom, b = 8.753(6) Angstrom, c = 13.696(3) Angstrom, alpha = beta = gamma = 90degrees, Z = 4; (III) a = 12.088(6) Angstrom, b = 8.566(4) Angstrom, c = 13.486(8) Angstrom, alpha = beta = gamma = 90degrees, Z = 4.