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化学学报
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化学学报 ›› 1989, Vol. 47 ›› Issue (8): 727-730.    下一篇

研究论文

冠醚配合物热力学性质的研究 X: 用NMR研究15-冠-5-衍生物与钠离子的配位反应

罗勤慧;冯旭东;沈孟长;屠庆云   

  1. 南京大学配位化学研究所
  • 发布日期:1989-08-15

Studies on thermodynamic properties of crown compounds X: Coordination reaction of methyl derivatives of 15-crown-5- with sodium ion by 23Na NMR

LUO QINHUI;FENG XUDONG;SHEN MENGCHANG;TU QINGYUN   

  • Published:1989-08-15

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461

被引次数

1

用^2^3Na NMR研究了15-冠-5(15C5), 2,3-苯并-15-冠-5(B-15C5), 2,3-苯并-6-甲基-15-冠-5(BCl-15C5), 2,3-苯并-8,12-二甲基-15-冠-5(BC2-15C5)在丙酮中与Na^+的配位反应, 由此探索甲基的影响, 实验结果表明, 当在金属盐溶液中加入冠醚, 配体为15C5时, 体系表观化学位移移至低场, 配体为B-15C5, BC1-15C5, BC2-15C5时, 体系在表观化学位移移至高场, 后者与苯并-18-冠-6及其甲基衍生物不同, 这是由于苯环在空间排布不同所致, 用Newton-Raphson法和描坑法(Pit-mapping)拟合实验数据, 发现BC1-15C5和BC2-15C5除形成NaL^+和NaL2^+外还有不稳定的Na3L2^3^+形成。本文对形成过程和生成NaL^+反应的平衡常数lgK11与甲基数的关系亦作了讨论, lgK11与甲基数目n近似成直线关系, 可用下式表示: lgK11=3.50-0.80n, n=0,1,2。

关键词: 钠化合物, 热力学性质, 计算, 核磁共振谱法, 冠式化合物, 丙酮, 平衡常数, 化学位移, 络合反应

The coordination reaction of 2,3-benzo-6-methyl-15-crown-5, 2,3-benzo-8,12-dimethyl-15-crown-5, 2,3-benzo-15-crown-5 and 15-crown-5 with sodium ion was studied by NMR in acetone to probe the effect of Me at crown ring on coordination ability and some regularities. On adding NaI to the crown solution the chem. shifts of 23Na shifted toward low field for 15C5 similar to that of benzo-derivs. of 18C6 but it shifted toward high field for 15C5 with benzo-ring. The difference may be due to orientation of benzo-ring in crowns. Fitting the data by Newton-Raphson and pit-mapping methods the unstable species Na3L23+ was found to form (L=BC1-15C5 and BC2-15C5) besides NaL+ and NaL2+. The formation reaction of Na3L23+ is discussed. A relationship was found between formation constants lg K11 of NaL and n, the no. of methyls, lg K11 = 3.50-0.48n (n = 0, 1, 2).

Key words: SODIUM COMPOUNDS, THERMODYNAMIC PROPERTIES, CALCULATION, NMR SPECTROMETRY, CROWN ETHER COMPOUNDS, ACETONE, EQUILIBRIUM CONSTANT, CHEMICAL SHIFT, COMPLEX REACTION

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