title: Conformational polymorphism in a chiral spiro-cis-ansa-bridged cyclotriphosphazene derivative.
abstract: The reaction of spermidine with 2,2,4,4-tetrachloro-6,6-diphenylcyclotriphosphazene produces a mixture of products of which one of the fractions is a spiro-cis-ansa derivative, namely 12-chloro-14,14-diphenyl-2,6,11,13,15,16-hexaaza-1,12-diphosphatricyclo[10.3.1.0(1,6)]hexadeca-12,14-diene, C19H26ClN6P3. Recrystallization of this fraction from different solvents results in the formation of two different crystalline forms. The rod morphology formed in dichloromethane-n-hexane (1:1) produces a triclinic structure with three molecules in the asymmetric unit. These three molecules adopt different conformations as a result of two NH groups flipping in an ansa-bridged ring system. The plate morphology crystals, grown in dichloromethane-n-hexane-ethyl acetate (1:1:1), produce a C-centred monoclinic structure that adopts a conformation that is essentially the same as one of the forms in the triclinic structure.
authors.affiliation: Department of Chemistry, University of Southampton, Southampton SO17 1BJ, England. s.j.coles@soton.ac.uk
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Coles
authors.forename: David B
authors.initials: DB
authors.lastname: Davies
authors.forename: Michael B
authors.initials: MB
authors.lastname: Hursthouse
authors.forename: Hanife
authors.initials: H
authors.lastname: Ibişoğlu
authors.forename: Adem
authors.initials: A
authors.lastname: Kiliç
authors.forename: Robert A
authors.initials: RA
authors.lastname: Shaw
mesh_terms: D001372:Aza Compounds / Q000737:chemistry*; D001713:Biphenyl Compounds / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006575:Heterocyclic Compounds, 3-Ring / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008968:Molecular Conformation
chemical_list: C450025:12-chloro-14,14-diphenyl-2,6,11,13,15,16-hexaaza-1,12-diphosphatricyclo(10.3.1.0(1,6))hexadeca-12,14-diene,; D001372:Aza Compounds; D001713:Biphenyl Compounds; D006575:Heterocyclic Compounds, 3-Ring