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 64.2° 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) Å, b = 8.853(2) Å, c = 13.753(3) Å, α = β = γ = 90°, Z = 4; (II) a = 12.438(6) Å, b = 8.753(6) Å, c = 13.696(3) Å, α = β = γ = 90°, Z = 4; (III) a = 12.088(6) Å, b = 8.566(4) Å, c = 13.486(8) Å, α = β = γ = 90°, Z = 4.