title: N-[2-[(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dien-1-ylidene)amino]phenyl]-N-(5,7-dinitroquinolin-8-yl)-1-phenylmethanesulfonamide: the nature of intramolecular shortened contacts.
abstract: The title compound, C(36)H(35)N(5)O(7)S, is found to exist in a non-spirocyclic (ring-opened) form in the crystal, although equilibrium of ring-opened and ring-closed forms (or so-called ring-chain isomerization) is possible in solution. The 4-oxocyclohexa-2,5-diene ring has a flattened sofa conformation. The N.C intramolecular separation of the atoms which would be directly bonded in a ring-closed form is quite short [2.813 (5) A]. Topological analysis of charge density based on density-functional-theory calculations was used for consideration of shortened intramolecular contacts and indicates a strong attractive bonding interaction between these N and C atoms in the crystal structure.
authors.affiliation: Department of Chemistry and Biochemistry, 251 Nieuwland Science Hall, University of Notre Dame, Notre Dame, Indiana 46556, USA. oborbulevych@yahoo.com
authors.forename: Oleg Ya
authors.initials: OY
authors.lastname: Borbulevych
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Kurbatov
authors.forename: Sergey N
authors.initials: SN
authors.lastname: Borisenko
authors.forename: Lev P
authors.initials: LP
authors.lastname: Olekhnovich