title: Two isomeric pairs of dihydrobenzopyrazoloquinazolines: centrosymmetric dimers, chains and sheets built from C-H...N and C-H...pi(arene) hydrogen bonds and pi-pi stacking interactions.
abstract: Molecules of 5-methyl-2-phenyl-6,7-dihydrobenzo[h]pyrazolo[1,5-a]quinazoline, C21H17N3, (I), are linked into chains by a combination of a C-H...pi(arene) hydrogen bond and a pi-pi stacking interaction; in the closely related 5-methyl-2-(4-methylphenyl)-6,7-dihydrobenzo[h]pyrazolo[1,5-a]quinazoline, C22H19N3, (II), there are no hydrogen bonds and the molecules are linked into centrosymmetric dimers by a pi-pi stacking interaction. 7-Methyl-10-phenyl-5,6-dihydrobenzo[h]pyrazolo[5,1-b]quinazoline, C21H17N3, (III), is isomeric with (I), and the molecules of (III) are linked into sheets by a combination of C-H...N and C-H...pi(arene) hydrogen bonds. 7-Methyl-10-(4-methylphenyl)-5,6-dihydrobenzo[h]pyrazolo[5,1-b]quinazoline, C22H19N3, (IV), is isomeric with (II), and molecules of (IV) are linked into centrosymmetric dimers by a C-H...pi(arene) hydrogen bond, augmented by pi-pi stacking interactions.
authors.affiliation: Grupo de Investigación de Compuestos Heterocíclicos, Departamento de Química, Universidad de Valle, AA 25360 Cali, Colombia.
authors.forename: Jaime
authors.initials: J
authors.lastname: Portilla
authors.forename: Jairo
authors.initials: J
authors.lastname: Quiroga
authors.forename: Justo
authors.initials: J
authors.lastname: Cobo
authors.forename: Manuel
authors.initials: M
authors.lastname: Nogueras
authors.forename: John N
authors.initials: JN
authors.lastname: Low
authors.forename: Christopher
authors.initials: C
authors.lastname: Glidewell
mesh_terms: D018360:Crystallography, X-Ray; D019281:Dimerization; D006860:Hydrogen Bonding; D007536:Isomerism; D008958:Models, Molecular; D011799:Quinazolines / Q000737:chemistry*
chemical_list: D011799:Quinazolines