title: Hydrogen bonding interaction of diphenylhydantoin and 9-ethyladenine.
abstract: A hydrogen-bonded complex of diphenylhydantoin (DPH) and 9-ethyladenine (EtAd) crystallizes from 2,4-pentanedione with the asymmetrical unit consisting of two DPH molecules, one EtAd molecule, and one solvent molecule. The crystal structure was solved by direct methods and refined to a residual of R = 0.054. Structure determination reveals that one DPH hydrogen-bonds to EtAd in a Watson-Crick scheme while the second DPH N(3)--H bonds to EtAd N(3) to form a 2:1 DPH-EtAd complex. Comparisons are made with barbiturate-adenine complexes and with an earlier postulation of a 1:1 DPH-EtAd complex derived from NMR and IR data. The 2,4-pentanedione molecule adopts the keto-enol configuration with an asymmetrical intramolecular hydrogen bond.
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000378:metabolism; D003460:Crystallization; D006860:Hydrogen Bonding; D008958:Models, Molecular; D010672:Phenytoin / Q000378:metabolism*
chemical_list: C001172:9-ethyladenine; D010672:Phenytoin; D000225:Adenine