title: Structural relationships in the solid state of the anti-chagas agent (E)-phenylethenylbenzofuroxan.
abstract: The crystal structure and the vibrational spectrum of a potential drug for Chagas's disease treatment, the (E)-isomer of phenylethenylbenzofuroxan 1 (5(6)(E)-[(2-phenylethenyl)]benzo[1,2-c]1,2,5-oxadiazole N-oxide), are reported. In order to provide insights into structural relationships, quantum mechanical calculations were employed starting from crystal structure. These results have given theoretical support to state interesting structural features, such as the effect of some intermolecular contacts on the molecule conformation and the electronic delocalization decreasing through atoms of the benzofuroxan moiety. Furthermore, the MOGUL comparative analysis in the Cambridge Structural Database provided additional evidences on these structural behaviors of compound 1. Intermolecular contacts interfere on the intramolecular geometry, as, for instance, on the phenyl group orientation, which is twisted by 12.32(6)° from the ethenylbenzofuroxan plane. The experimental Raman spectrum of compound 1 presents unexpected frequency shift and also anomalous Raman activities. At last, the molecule skeleton deformation and the characteristic vibrational modes were correlated by matching the experimental Raman spectrum to the calculated one.
authors.affiliation: Instituto de Física de São Carlos, Universidade de São Paulo, CP 369, Sao Carlos, 13560-970, SP, Brazil.
authors.forename: Felipe Terra
authors.initials: FT
authors.lastname: Martins
authors.forename: Alejandro Pedro
authors.initials: AP
authors.lastname: Ayala
authors.forename: Williams
authors.initials: W
authors.lastname: Porcal
authors.forename: Hugo
authors.initials: H
authors.lastname: Cerecetto
authors.forename: Mercedes
authors.initials: M
authors.lastname: González
authors.forename: Javier
authors.initials: J
authors.lastname: Ellena
mesh_terms: D000981:Antiprotozoal Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000627:therapeutic use*; D001583:Benzoxazoles / Q000138:chemical synthesis / Q000737:chemistry* / Q000627:therapeutic use*; D014355:Chagas Disease / Q000188:drug therapy*; D018360:Crystallography, X-Ray; D003497:Cyclic N-Oxides / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D008954:Models, Biological; D008958:Models, Molecular; D015394:Molecular Structure; D010069:Oxadiazoles / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology / Q000627:therapeutic use; D044367:Phase Transition; D013059:Spectrum Analysis, Raman; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D014961:X-Ray Diffraction
chemical_list: C556666:5(6)-(2-phenylethenyl)benzo(1,2-c)1,2,5-oxadiazole N-oxide; D000981:Antiprotozoal Agents; D001583:Benzoxazoles; D003497:Cyclic N-Oxides; D010069:Oxadiazoles; C014354:benzofuroxan