Hydrogen bond studies. LXXXIV. An X-ray diffraction study of the structures of KHCO3 and KDCO3 at 298, 219 and 95 K
Hydrogen bond studies. LXXXIV. An X-ray diffraction study of the structures of KHCO3 and KDCO3 at 298, 219 and 95 K
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氢键研究。
DOI：
10.1107/s0567740874004481
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发表时间：
1974
期刊：
影响因子：
--
通讯作者：
I. Olovsson
中科院分区：
文献类型：
--
作者：
J. O. Thomas;R. Tellgren;I. Olovsson
利用半自动Stoe-Philips Weissenberg衍射仪采集的三维单晶x射线数据，研究了298、219和95K下正常和氘化碳酸氢钾KHCO3和KDCO3的晶体结构。两个单位胞都是单斜的，包含四个公式单元，具有中心对称的空间群P2~/a（选择与先前关于KHCO3的工作一致）。298K时KHCO3的胞格尺寸为：a= 15.1725 (11), b= 5.6283 (5), c= 3.7110 (4) a, fl= 104.631 (6)， V= 306.62 A3；KDCOa: a= 15.1948 (9), b= 5.6307 (3), c= 3.7107 (3) a, fl= 104-567 (5)， V= 307.27 a。kdco3由（HCO3） 2-二聚体和K+离子组成，与它的氘化产物是同构的。中心对称二聚体中每个HCOs离子的重原子在所有温度下都紧密共面，这些面之间的距离为~ 0.22 A。这两个对称的羟基…二聚体中O型氢键在298、219和95K时的长度分别为2′585(2)、2.592(2)和2.591 (2)A。KDCO3中对应的长度分别为：2.607(2)、2.613(2)和2.606 (2)A，说明在3种温度下氘化后长度分别增加了0.022、0.021和0.015 A。最终得到的KHCO3的R (F)值分别为0.037、0.028和0.031。相应的KDCO3值分别为0.034、0.033和0.033。
The crystal structures of normal and deuterated potassium hydrogen carbonate, KHCO3 and KDCO3, have been studied at 298, 219 and 95K using three-dimensional single-crystal X-ray data collected on a semi-automatic Stoe-Philips Weissenberg diffractometer. Both unit cells are monoclinic, containing four formula units and having the centrosymmetric space group P2~/a (chosen to conform with previous work on KHCO3). The cell dimensions at 298K for KHCO3 are: a= 15.1725 (11), b= 5.6283 (5), c= 3.7110 (4) A, fl= 104.631 (6), V= 306.62 A3; and for KDCOa: a= 15.1948 (9), b= 5.6307 (3), c= 3.7107 (3) A, fl= 104-567 (5), V= 307.27 A s. The KHCO3 structure, comprising (HCO3) 2-dimers and K+ ions, is isomorphous with its deuterated counterpart. The heavy atoms of each HCOs ion within the centrosymmetric dimer are closely coplanar at all temperatures, the separation between these planes being~ 0.22 A. The two symmetry-related OH... O hydrogen bonds within the dimer have lengths 2" 585 (2), 2.592 (2) and 2.591 (2) A at 298, 219 and 95K, respectively. The corresponding lengths in KDCO3 are: 2.607 (2), 2.613 (2) and 2.606 (2) A, implying length increases of 0.022, 0.021 and 0.015 A on deuteration at the three temperatures. The final R (F) values obtained for the refinements of KHCO3 were 0.037, 0.028 and 0.031, respectively. The corresponding values for KDCO3 were 0.034, 0.033 and 0.033.