复合型POM：3，5－DNBA的晶体结构

Crystal Structure of Complex POM:3,5-DNBA

３－甲基－４－硝基吡啶－１－氧（ＰＯＭ）与３，５－二硝基苯甲酸（３，５－ＤＮＢＡ）的复合型晶体从乙醇与丙酮的混合溶液中培养获得，其组成为１：１，己被元素分析和ｘ射线衍射实验所证实；其熔点由ＤＳＣ热分析测得，为１２２．６℃。该晶体化合物属单斜晶系，空间群为Ｐ２１／ｎ，单胞参数为：ａ＝０．９５５３（２）ｎｍ，ｂ＝０．５７７５（４）ｎｍ，ｃ＝２．７９６２（４）ｎｍ，β＝９９．０３（１）°，ｖ＝１．５２４（１）ｎｍ３，ｚ＝４，Ｄｃ＝１．６０ｇ／ｃｍ３，λ（Ｍｏｋα）＝０．０７１０７３ｎｍ，μ＝１．２９ｃｍ－１，Ｆ（０００）＝７５２，最终Ｒ＝０．０５１，Ｒｗ＝０．１６５［ｗ＝１／σ２（Ｆ）］，其中１８０２个可观察衍射点参与结构计算，复合型分子中存在一个氢键。

Single crystals of complex 3-methyl-4-nitropyridine-1-oxidc(POM):3,5-dinitrobenzoic acid(3,5-DNBA) have been grown and obtained from solution using a 5:4mixture of ethand and acetone. Formation of an equimolar complex is confirmed by clementary analyses and x-ray diffraction studies.The melting point determined by differential seanning calorimetry is 122.6℃.The complex crystallizes in the monoclinic space group P21/n,a=0.9553(2) nm,b= 0.5775(4) nm,c=2.7962(4) nm, β=99.03(1)°,v=1.524(1)nm3, z=4, Dc=1.60 g/cm3.λ(Mokα=0.071 073 nm,μ=1.29 cm-1, F(000) = 752,final R=0.051, Rw=0. 065[w=1/σ2(F)] for 1 802 observed reflections [I≥3σ(I)].There is one hydrogen bond between the hydrogen of the carboxyl group of 3,5-dinitrobenzoic and the oxygen atom of POM in the complex(a-c plane).