Crystal structures of complexes between alkali-metal salts and cyclic polyethers. Part II. Complex formed from sodium bromide and 2,3,11,12-dibenzo-1,4,7,10,13,16-hexaoxacyclo-octadeca-2,11-diene (‘di-benzo-18-crown-6’)
Crystal structures of complexes between alkali-metal salts and cyclic polyethers. Part II. Complex formed from sodium bromide and 2,3,11,12-dibenzo-1,4,7,10,13,16-hexaoxacyclo-octadeca-2,11-diene (‘di-benzo-18-crown-6’)
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碱金属盐和环状聚醚之间的络合物的晶体结构，由溴化钠和2,3,11,12-二苯并-1,4,7,10,13,16-六氧杂环-十八-2形成。 11-二烯（二苯并-18-冠-6）
DOI：
10.1039/j29710001440
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发表时间：
1971
期刊：
影响因子：
--
通讯作者：
M. Truter
中科院分区：
文献类型：
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作者：
M. Bush;M. Truter
溴化钠在甲醇中与环醚二苯并-18-冠-6（L）反应，得到式NaBrL·2 H2O的晶体。三维X射线晶体结构分析表明，晶体中存在两种钠络合物：（A）络合阳离子，（B）络合离子对。在这两种情况下，钠离子都有一个六方双锥环境，在赤道平面上有六个氧原子从L开始;在（A）中，顶点被2.31和2.27 A处的水分子占据，而在（B）中，一个顶点被2.35 A处的水分子占据，另一个顶点被2.82 A处的溴离子占据。非配位的水分子和非配位的溴离子以及配位的水分子和溴离子的氢键作用导致了一条平行于晶体的B轴的链，两个配合物沿该链交替沿着排列。两个环醚分子都具有正常的键长和键角，并且具有与先前在（Rb 0·55，Na 0·45）NCS配合物中发现的相同的构象。钠-氧（醚）距离平均值为2·705 A（A）中的（2.64 - 2.84 A）和（2.72 A）（B）中的（2·54-2·89 A）。两个分子式单元C20 H24 O 6，NaBr，2 H2O构成单斜晶胞中的不对称单元，a= 10·558，B= 14·036，c= 30·677 A，β= 91·3°，空间群P21/c。用四圆衍射仪测量强度。非氢原子的位置来自帕特森和傅立叶合成，它们的参数通过全矩阵最小二乘法进行了修正，最终R为0.083，用于2880次观测。
Sodium bromide reacts in methanol with the cyclic ether dibenzo-18-crown-6(L) to yield crystals of formula NaBrL,2H2O. Three-dimensional X-ray crystal structure analysis has shown that there are two kinds of sodium complex in the crystal, (A) a complexed cation, and (B) a complexed ion-pair. In both, the sodium ions have a hexagonal bipyramidal environment, with six oxygen atoms from L in the equatorial plane; the apices are occupied by water molecules at 2·31 and 2·27 A in (A), while one apex is occupied by a water molecule at 2·35 A, and the other by a bromide ion at 2·82 A in (B). Hydrogen bonding involving the unco-ordinated molecule of water and the unco-ordinated bromide ion, as well as the co-ordinated water molecules and bromide ion, results in a chain parallel to the b axis of the crystal with the two complexes alternately along it. Both molecules of cyclic ether have normal bond lengths and angles and the same conformation as found previously in the (Rb0·55, Na0·45)NCS complex. Sodium–oxygen (ether) distances average 2·705 A(2·64–2·84 A) in (A), and 2·72 A(2·54–2·89 A) in (B).Two formula units, C20H24O6, NaBr, 2H2O, comprise the asymmetric unit in a monoclinic unit cell with a= 10·558, b= 14·036, c= 30·677 A, β= 91·3°, and space group P21/c. Intensities were measured with a four-circle diffractometer. Non-hydrogen atoms were located from Patterson and Fourier syntheses and their parameters were refined by full-matrix least-squares methods to a final R of 0·083 for 2880 observations.