title: Crystal structure of dimethyl 3,3'-[(4-fluoro-phen-yl)methyl-ene]bis-(1H-indole-2-carboxyl-ate).
abstract: In the title compound, C27H21FN2O4, the mean planes of the indole ring systems (r.m.s. deviations = 0.0263 and 0.0160 Å) are approximately perpendic-ular to one another, making a dihedral angle of 84.0 (5)°; the fluoro-benzene ring is twisted with respect to the mean planes of the two indole ring systems at 89.5 (5) and 84.6 (3)°. In the crystal, pairs of N-H⋯O hydrogen bonds link the mol-ecules into inversion dimers, which are further linked by N-H⋯O hydrogen bonds into supra-molecular chains propagated along the b-axis direction. Weak C-H⋯π inter-actions are observed between neighbouring chains.
authors.affiliation: Chemical Engineering Department, Nanjing Polytechnic Institute, Nanjing 210048, People's Republic of China.
authors.forename: Hong-Shun
authors.initials: HS
authors.lastname: Sun
authors.affiliation: Chemical Engineering Department, Nanjing Polytechnic Institute, Nanjing 210048, People's Republic of China.
authors.forename: Yu-Long
authors.initials: YL
authors.lastname: Li
authors.affiliation: Chemical Engineering Department, Nanjing Polytechnic Institute, Nanjing 210048, People's Republic of China.
authors.forename: Hong
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Chemical Engineering Department, Nanjing Polytechnic Institute, Nanjing 210048, People's Republic of China.
authors.forename: Ning
authors.initials: N
authors.lastname: Xu
authors.affiliation: Chemical Engineering Department, Nanjing Polytechnic Institute, Nanjing 210048, People's Republic of China.
authors.forename: Hong
authors.initials: H
authors.lastname: Xu
keywords: C—H⋯π inter­actions; MRI contrast agent; N—H⋯O hydrogen bonds; bis-indolymethane; crystal structure; indole