Crystal and molecular structure ofN-[2-phenyl-glyoxylohydroximoyl]-pyridinium bromide,C13H11N2O2Br

The crystal structure of the title compound, C₁₃H₁₁N₂O₂Br, has been determined by three-dimensional X-ray diffraction data. The crystals are monoclinic,P2₁/c:a=8.3029(9),b=12.798(3),c=12.314(2) Å,=105.94(1)°,Z=4. The structure was solved by Patterson and Fourier methods and refined to anR value of 0.044 for 1924 observed reflections. The phenyl ring shows a mean C-C bond length significantly short, 1.375(4) Å; all other bond lengths and angles have normal values, and a -delocalization is evident within the molecule, with the exclusion of the pyridinium. The two rings are in reciprocaltrans-position [=–170.5(2)°], whereas the oxime and the pyridinium are incis-position [=2.0(3)°]. A hydrogen bridge connects the bromide ion and the oxime [Br^–H: 1.91(2) Å] and there are also two short approaches of the bromide ions with carbon atoms, which ensure the crystalline cohesion.