title: Crystal structure determination of mebendazole form A using high-resolution synchrotron x-ray powder diffraction data.
abstract: The crystal structure determination of mebendazole form A, an anthelmintic drug, was performed for the first time by applying the DASH software program to synchrotron X-ray powder diffraction data, and supported by a satisfying Rietveld fit. This polymorph of mebendazole crystallizes in a triclinic (P1) space group, with unit-cell parameters a = 5.5044(2) A, b = 11.2872(2) A, c = 12.5276(5) A, alpha = 66.694(2) degrees, beta = 82.959(2) degrees, gamma = 78.443(2) degrees, V = 699.52(5) A(3), Z = 2, M = 295.293 g mol(-1), rho(calc) = 1.4021 g cm(-3), and rho(meas) = 1.3935(66) g cm(-3), which were obtained by means of the unit-cell formula weight and a picnometric measurement, respectively. The goodness-of-fit and R-factors were, respectively: chi(2) = 1.746, R(F)(2) = 1.69%, R(wp) = 5.72%, and R(p) = 4.37%. A weak nonclassical hydrogen bond involving the atoms N(3)-H(23)...O(11) may be responsible for the greater stability of the polymorphic form A of mebendazole due to the strongest electronegativity of nitrogen.
authors: Laboratório Nacional de Luz Síncrotron, Caixa Postal 6192, CEP: 13083-970, Campinas, SP, Brazil. ffurlanf@gmail.com
authors: Fabio Furlan
authors: FF
authors: Ferreira
authors: Selma Gutierrez
authors: SG
authors: Antonio
authors: Paulo César Pires
authors: PC
authors: Rosa
authors: Carlos de Oliveira
authors: Cde O
authors: Paiva-Santos
mesh_terms: D000465:Algorithms; D000871:Anthelmintics / Q000737:chemistry*; D018360:Crystallography, X-Ray / Q000379:methods*; D008463:Mebendazole / Q000737:chemistry*; D012984:Software
chemical_list: D000871:Anthelmintics; D008463:Mebendazole