Abstract
The compound diisopropyl 11-(4-phenylbenzoyl)-pyrrolo[1,2-a][1,10]phenanthroline-9,10-dicarboxylate 1 contains a pyrrole ring bearing three bulky substituents. X-ray analysis was undertaken to establish the effect of this substitution on the helical distortion reported previously for molecules in this class. Compound 1 crystallizes in the space group P1 with a = 12.0300(2)Å, b = 16.1897(3)Å, c = 17.0965(4)Å, α = 109.934(1)°, β = 102.655(1)°, γ = 99.678(1)° and Z = 4. The extent of helical distortion is significant and comparable in the two crystallographically independent molecules, the average angle between the pyrrole ring plane and the terminal pyridine ring being ∼20°.
