Smith Graham, Wermuth Urs D
Faculty of Science and Technology, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia.
Acta Crystallogr Sect E Struct Rep Online. 2011 Aug 1;67(Pt 8):m1047-8. doi: 10.1107/S1600536811026614. Epub 2011 Jul 9.
In the structure of title compound, Cs(2)(C(7)H(5)N(2)O(4))(2)(H(2)O)(2), the asymmetric unit contains two independent Cs atoms comprising different coordination polyhedra. One is nine-coordinate, the other seven-coordinate, both having irregular configurations. The CsO(9) coordination polyhedron comprises O-atom donors from three bridging water mol-ecules, one of which is doubly bridging, three from carboxyl-ate groups, and three from nitro groups, of which two are bidentate chelate bridging. The CsO(6)N coordination polyhedron comprises the two bridging water mol-ecules, one amine N-atom donor, one carboxyl-ate O-atom donor and four O-atom donors from nitro groups (two from the chelate bridges). The extension of the dimeric unit gives a three-dimensional polymeric structure, which is stabilized by both intra- and inter-molecular amine N-H⋯O and water O-H⋯O hydrogen bonds to carboxyl-ate O-atom acceptors, as well as inter-ring π-π inter-actions [minimum ring centroid-centroid separation = 3.4172 (15) Å].
在标题化合物[Cs₂(C₇H₅N₂O₄)₂(H₂O)₂]ₙ的结构中，不对称单元包含两个具有不同配位多面体的独立铯原子。一个是九配位，另一个是七配位，两者构型均不规则。CsO₉配位多面体包含来自三个桥连水分子的氧原子供体，其中一个是双桥连的，三个来自羧酸根基团，三个来自硝基，其中两个是双齿螯合桥连。CsO₆N配位多面体包含两个桥连水分子、一个胺氮原子供体、一个羧酸根氧原子供体以及来自硝基的四个氧原子供体（两个来自螯合桥）。二聚单元的扩展形成三维聚合结构，该结构通过分子内和分子间的胺N—H⋯O和水O—H⋯O氢键与羧酸根氧原子受体相互作用而稳定，同时还存在环间π - π相互作用[最小环质心 - 质心间距 = 3.4172 (15) Å]。
