CRYSTAL-STRUCTURE OF CYCLOTRIMETHYLENE-TRINITRAMINE
CRYSTAL-STRUCTURE OF CYCLOTRIMETHYLENE-TRINITRAMINE
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DOI：
10.1107/s0567740872007046
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发表时间：
1972-01-01
期刊：
影响因子：
--
通讯作者：
PRINCE, E
中科院分区：
文献类型：
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作者：
CHOI, CS;PRINCE, E
本文用单晶中子衍射数据对环三亚甲基三硝胺（RDX）CzH 6 N606的结构进行了修正。836个独立反射的最终加权R指数为0.021。晶体属正交晶系，空间群Pbca，a= 13”182（2），B= 11”574（2），c= 10-709（2）A，Z= 8。该分子由褶皱环中交替的CH 2和N-NO2基团组成。碳原子的环境基本上是四面体的，并且N-NO2基团是平面的。该分子具有垂直于由三个碳原子限定的平面的近似镜像对称的平面。热运动可以描述为刚体运动的环和单独的刚体运动的硝基groups.Introduction化合物环三亚甲基-三硝胺，C3 H6 N606，也被称为Cyclonite，或由代码指定RDX，是一种众所周知的炸药。有两种已知的多晶型，称为RDX（I）和RDX（II）（McCrone，1950）。RDX（II）的结构还没有确定，因为由于其极不稳定性，即使在短时间内也难以获得和保存良好的晶体。本文介绍了RDX（Ⅰ）结构的改进，以下简称RDX。黑索今的晶体结构首先由Hultgren（1936）研究。他报告说，它具有正交对称性，每个晶胞有8个分子，最可几空间群为V~ S（Pbca）。Mc-Crone（1950）报道了完整的晶体形态。Harris和Reed（1959）利用三维X射线照相数据重新研究了RDX的晶体结构。他们确定了除了氢位置之外的完整晶体结构。本研究通过确定氢的位置和细化整体结构细节来完成晶体结构。
The structure of cyclotrimethylene-trinitramine (RDX), CzH6N606, has been refined from single-crystal neutron-diffraction data. The final weighted R index for 836 independent reflections is 0.021. The compound crystallizes in the orthorhombic space group Pbca, a= 13" 182 (2), b= 11" 574 (2), c= 10-709 (2) A, Z= 8. The molecule consists of alternate CH2 and N-NO2 groups in a puckered ring. The environment of the carbon atoms is essentially tetrahedral, and the N-NO2 groups are planar. The molecule possesses a plane of approximate mirror symmetry perpendicular to the plane defined by the three carbon atoms. The thermal motion may be described by rigid-body motion of the ring and separate rigid-body motion of the nitro groups.Introduction The compound cyclotrimethylene-trinitramine, C3H6N606, also known as Cyclonite, or by the code designation RDX, is a well known explosive. There are two known polymorphic forms, designated RDX (I) and RDX (II)(McCrone, 1950). The structure of RDX (II) has not been determined because of the dif-ficulty of obtaining and preserving well formed crys-tals, even for short periods, owing to its extreme insta-bility. This paper describes the refinement of the struc-ture of RDX (I); it will be referred to hereafter simply as RDX. The crystal structure of RDX was first investigated by Hultgren (1936). He reported that it possesses or-thorhombic symmetry, with eight molecules per unit cell and most probable space group V~ S (Pbca). A com-plete crystal morphology has been reported by Mc-Crone (1950). The crystal structure of RDX was re-investigated by Harris & Reed (1959) using three-di-mensional X-ray photographic data. They determined the complete crystal structure except for the hydrogen positions. The present study was undertaken to com-plete the crystal structure by determining the hydrogen positions and refining overall structural details.