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化学学报
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化学学报 ›› 1994, Vol. 52 ›› Issue (3): 261-267. 上一篇    下一篇

研究论文

(η^5-C~5H~5)~3Ln.OC~4H~8(Ln=Ce, Er)的合成及晶体结构

陈文启;林观阳;夏巨松;卫革成;张引;金钟声   

  1. 中国科学院长春应用化学研究所
  • 发布日期:1994-03-15

Syntheses and crystal structure of -(η^5-C~5H~5)~3Ln.OC~4H~8(Ln=Ce, Er)

CHEN WENQI;LIN GUANYANG;XIA JUSONG;WEI GECHENG;ZHANG YIN;JIN ZHONGSHENG   

  • Published:1994-03-15

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用无水硝酸铈铵[(NH~4)~2Ce(NO~3)~6]与环戊二烯钠(C~5H~5Na)在四氢呋喃中1:6摩尔比反应, 得到(η^5-C~5H~5)~3Ce.OC~4H~8; 用ErCl~3.nTHF与环辛二烯钾(C~8H~11K)按等摩尔比于-78℃反应, 升至室温, 再按1:2摩尔比加入C~5H~5Na, 得到了(η^5-C~5H~5)~3Er.OC~4H~8。两配合物晶体结构测定结果表明都属单斜晶系P2~1/n空间群。Ce配合物与已测定过的(η^5-C~5H~5)~3Ln.OC~4H~8(Ln=La, Pr,Nd, Gd, Dy, Y, Lu)的晶体结构不是同构物; 而Er配合则是同构物。Ce配合物中的Ce-O、Ce-Cent(环戊二烯环中心)和平均Ce-C(η^5)键长不符合镧系收缩规律, 而Er配合物的键长符合。这说明在(η^5-C~5H~5)~3Ln.OC~4H~8同构系列中的Ce和Dy有两个断点, 但不存在所谓的“钆断现象”, 因为Y, Er, Lu配合物的Ln-O和Ln-C(η^5)和Ln-Centroid距离不大于Gd的相应值。

关键词: 晶体结构测定, 环戊二烯 P, 四氢呋喃, 铈络合物, 铒络合物, 氯化铒, 硝酸铈铵, 环辛二烯钾

reaction of (NH4)2Ce(NO3)6 with sodium cyclopentadienide (C5H5Na) in THF at a molar ratio of 1:6 to give a brown crystal of (h5-C5H5)3Ce譕C4H8; (tricyclopentadienyl)erbium tetrahydrofuranate complex was synthesized by the reaction of ErCl3譶THF with potassium cyclooctadienide (C8H11K) at a molar ratio of 1:1 at -78癈, and then C5H5Na in THF (at molar ratio of ErCl3譶THF to C5H5Na 1:2) was added to the above solution at room temperature to give the pink crystal of (h5-C5H5)3Er譕C4H8. The crystal structure determination of both complexes showed that both crystals belong to monoclinic space group P21/n. The Ce complex structure is different from those of (h5-C5H5)3Ln譕C4H8 (Ln = La, Pr, Nd, Gd, Dy, Y, Lu). They are not isostructural, but the Er complex is isostructural with them. The distance Ce-O, average Ce-C(h5) and Ce-Cent (centroid of cyclopentadienyls) are not consistent with the lanthanide contraction regularity, but those of Er-O, average Er-C(h5) and Er-Cent are consistent with it. It means that there are two discontinuity points at Ce and Dy but no "gadolinium break phenomenon" is observed in the isostructural series of (h5-C5H5)3Ln譕C4H8 because the bond lengths of Ln-O and Ln-C(h5) and the Ln-centroid distance of the elements (Y, Er, Lu) are not greater than those of Gd.

Key words: CRYSTAL STRUCTURE DETERMINATION, CYCLOPENTADIENE P, TETRAHYDROFURAN, CERIUM COMPLEX, ERBIUM COMPLEX, ERBIUM CHLORIDE

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