Chernyshev Vladimir V, Shkavrov Sergey V, Paseshnichenko Ksenia A, Puryaeva Tamara P, Velikodny Yurii A
Department of Chemistry, M. V. Lomonosov Moscow State University, 119991 Moscow, Russian Federation.
Acta Crystallogr C. 2013 Mar;69(Pt 3):263-6. doi: 10.1107/S0108270113003089. Epub 2013 Feb 5.
The crystal structures of the monoclinic and triclinic polymorphs of zoledronic acid, C5H10N2O7P2, have been established from laboratory powder X-ray diffraction data. The molecules in both polymorphs are described as zwitterions, namely 1-(2-hydroxy-2-phosphonato-2-phosphonoethyl)-1H-imidazol-3-ium. Strong intermolecular hydrogen bonds (with donor-acceptor distances of 2.60 Å or less) link the molecules into layers, parallel to the (100) plane in the monoclinic polymorph and to the (1-10) plane in the triclinic polymorph. The phosphonic acid groups form the inner side of each layer, while the imidazolium groups lie to the outside of the layer, protruding in opposite directions. In both polymorphs, layers related by translation along [100] interact through weak hydrogen bonds (with donor-acceptor distances greater than 2.70 Å), forming three-dimensional layered structures. In the monoclinic polymorph, there are hydrogen-bonded centrosymmetric dimers linked by four strong O-H...O hydrogen bonds, which are not present in the triclinic polymorph.
已根据实验室粉末X射线衍射数据确定了唑来膦酸（C5H10N2O7P2）单斜晶型和三斜晶型的晶体结构。两种晶型中的分子均被描述为两性离子，即1-(2-羟基-2-膦酰基-2-膦酰基乙基)-1H-咪唑-3-鎓。强分子间氢键（供体-受体距离为2.60 Å或更小）将分子连接成层，在单斜晶型中平行于(100)面，在三斜晶型中平行于(1-10)面。膦酸基团形成每层的内侧，而咪唑鎓基团位于层的外侧，向相反方向突出。在两种晶型中，沿[100]平移相关的层通过弱氢键（供体-受体距离大于2.70 Å）相互作用，形成三维层状结构。在单斜晶型中，存在由四个强O-H...O氢键连接的氢键中心对称二聚体，而在三斜晶型中不存在。
