title: A second monoclinic polymorph of 4,4'-[butane-1,4-diylbis(nitrilo-methyl-idyne)]dibenzonitrile.
abstract: The asymmetric unit of the title Schiff base compound, C(20)H(18)N(4), contains one half-mol-ecule, lying across a crystallographic inversion centre and adopting an E configuration with respect to the C=N bonds. The imino group is coplanar with the benzene ring with a maximun deviation of 0.096 (1) Å for the N atom. Within the molecule, the planar units are parallel but extend in opposite directions from the methylene bridge. In the crystal structure, neighbouring mol-ecules are linked together by weak inter-molecular C-H⋯N hydrogen bonds involving the cyano N atoms, forming R(2) (2)(10) ring motifs.
authors.forename: Reza
authors.initials: R
authors.lastname: Kia
authors.forename: Hoong-Kun
authors.initials: HK
authors.lastname: Fun
authors.forename: Hadi
authors.initials: H
authors.lastname: Kargar