Crystal and molecular structure of 8,12-diethyl-2,3,7,13,17,18-hexamethylcorrole

The crystal structure of 8,12-diethyl-2,3,7,13,17,18-hexamethylcorrole has been elucidated by X-ray crystallographic analysis and the geometry of the macrocyclic ring system has been found to be not strictly planar. The distortions are probably caused by short N–N contacts brought on by the direct C(1)–C(19) link. The ‘ruffling’ of the pyrrole rings is similar to that found in some substituted porphyrins, although individual ring geometries have been altered by the inner crowding. Crystallographic evidence suggests that the three inner hydrogen atoms are statistically distributed among the four nitrogen atoms. Packing is in the ‘parallel disc’ mode and is specific for the molecular distortion.