HEXA-N-PYRROLEBENZENE, TETRA-N-PYRROLEETHYLENE, AND RELATED COMPOUNDS. Frank R. Fronczek, Alfonso Dávila, Tamara R. Nauman, and Mark L. McLaughlin, Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA.

Hexa-N-pyrrolebenzene (I) has a propeller conformation, with pyrrole rings forming dihedral angles with the benzene plane ranging 49.2(1)-67.9(1)deg.. Tetra-N-pyrroleethylene (II) lies on a crystallographic twofold axis, and pyrrole rings form dihedral angles of 51.9(1) and 46.5(1)deg. with the plane of the double bond. In III, the pyrrole rings form dihedral angles of 36.2(1) and 56.0(1)deg. with the plane of the double bond. IV lies on an inversion center, and the C=C carbon atoms are disordered into two sets of sites with relative populations ca. 2:1. The pyrrole plane forms a dihedral angle of 67.7(1)deg. with the plane of the double bond.

I has Z=4 in Pna2₁, R=0.047; II has Z=4 in C2/c, R=0.041; III has Z=4 in P2₁/c, R=0.055; IV has Z=2 in P2₁/n, R=0.031.