title: 2,4-Diamino-5-(1-naphthyl)-3,5-diaza-1-azoniaspiro[5.5]undeca-1,3-diene chloride.
abstract: The title salt, C(18)H(22)N(5)(+).Cl(-), is a member of a new series of lipophilic 4,6-diamino spiro-s-triazines which are potent inhibitors of dihydrofolate reductase. The protonated triazine ring deviates from planarity, whereas the cyclohexane ring adopts a chair conformation. A rather unusual hydrogen-bonding scheme exists in the crystal. There is a centrosymmetric arrangement involving two amino groups and two triazine ring N atoms, with graph-set R(2)(2)(8) and an N.N distance of 3.098 (3) A, flanked by two additional R(3)(2)(8) systems, involving two amino groups, a triazine ring N atom and a Cl(-) anion, with N.Cl distances in the range 3.179 (2)-3.278 (2) A. Furthermore, the Cl(-) anion, the protonated triazine ring N atom and an amino group form a hydrogen-bonding system with graph-set R(2)(1)(6).
authors.affiliation: Department of Cell Biology and Biophysics, Faculty of Biology, University of Athens, Panepistimiopolis 157 01, Athens, Greece.
authors.forename: Nikolaos C
authors.initials: NC
authors.lastname: Papandreou
authors.forename: Stella
authors.initials: S
authors.lastname: Makedonopoulou
authors.forename: Ekaterini A
authors.initials: EA
authors.lastname: Antoniadou-Vyza
authors.forename: Irene M
authors.initials: IM
authors.lastname: Mavridis
authors.forename: Stavros J
authors.initials: SJ
authors.lastname: Hamodrakas
mesh_terms: D003461:Crystallography; D006860:Hydrogen Bonding; D008958:Models, Molecular; D015394:Molecular Structure; D009281:Naphthalenes / Q000737:chemistry*; D013141:Spiro Compounds / Q000737:chemistry*
chemical_list: C472319:2,4-diamino-5-(1-naphthyl)-3,5-diaza-1-azoniaspiro(5.5)undeca-1,3-diene chloride; D009281:Naphthalenes; D013141:Spiro Compounds