Optical Properties, Thermochromism, and Crystal Structures of the Dimorphs of 2-Iodoanilinium Picrate
Optical Properties, Thermochromism, and Crystal Structures of the Dimorphs of 2-Iodoanilinium Picrate
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2-碘苯胺苦味酸二晶型的光学性质、热致变色和晶体结构
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
S. Kashino
中科院分区：
文献类型：
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作者：
Masashi Tanaka;Hiroaki Matsui;J. Mizoguchi;S. Kashino
苦味酸2-碘苯胺的晶体有三种多晶型。用x射线衍射法测定了单斜晶型（型I）和三斜晶型（型II）的晶体结构。第三种形式的晶体（形式III）是不稳定的。在I型和II型中，2-碘苯胺离子和苦克酸阴离子形成了一个近平面的离子对，具有相似的N-H···O氢键几何形状。在形式I中，由平移相关的对相互堆叠形成分离柱，其中同种离子相互堆叠，而在形式II中，阴离子和阳离子交替堆叠形成连续柱。通过偏振可见光谱、红外吸收光谱和差示扫描量热法研究了晶体的热致变色性。
The crystals of 2-iodoanilinium picrate have three polymorphic forms. The crystal structures of the monoclinic form (form I) and the triclinic form (form II) have been determined by the X-ray diffraction method. The crystals of the third form (form III) are unstable. In forms I and II, 2-iodoanilinium cation and picrate anion form a nearly planar pair of these ions with similar geometry of N–H···O hydrogen bond. In form I the pairs related by a translation are stacked to form the segregated columns, in which the same kinds of ions are stacked with each other, while in form II the anions and cations are alternately stacked to form the continuous columns. The thermochromism of these crystals was studied by measuring the polarized visible and IR absorption spectra and the differential scanning calorimetry.