title: N-(o-chlorophenyl)-2,5-dimethylpyrrole-3-carbaldehyde.
abstract: Crystal structure analysis of the title compound, C(13)H(12)ClNO, reveals three crystallographically independent molecules in the asymmetric unit. The main conformational difference between these molecules is the orientation of the phenyl rings with respect to the pyrrole rings. The coplanar arrangement of the aldehyde groups attached to the pyrrole rings influences the pyrrole-ring geometry. The C2-C3 and N1-C5 bonds are noticeably longer than the C4-C5 and N1-C2 bonds. Two independent molecules of the title compound form dimers via intermolecular C-H.O hydrogen bonds [D.A = 3.400 (3) A and D-H.A = 157 degrees ]. The perpendicular orientation of the phenyl and pyrrole rings of one independent molecule and its symmetry-related molecule allows C-H.pi interactions, with an H.centroid distance of 2.85 A and a C-H.pi angle of 155 degrees. The distances between the H atom and the pyrrole-ring atoms indicate that the C-H bond points towards one of the bonds in the pyrrole ring.
authors.affiliation: Laboratory of Organic Chemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, HR-10000 Zagreb, Croatia.
authors.forename: Marijana
authors.initials: M
authors.lastname: Jukić
authors.forename: Mario
authors.initials: M
authors.lastname: Cetina
authors.forename: Jasna
authors.initials: J
authors.lastname: Vorkapić-Furac
authors.forename: Amalija
authors.initials: A
authors.lastname: Golobic
authors.forename: Ante
authors.initials: A
authors.lastname: Nagl