鑭系金屬與1,2,4,5-苯四酸配子之自組裝合成、結構與性質探討; Self-assembly, Structure and Properties of Lanthanide Complexes with 1,2,4,5-Benzenetetracarboxylate

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/43735

Title:	鑭系金屬與1,2,4,5-苯四酸配子之自組裝合成、結構與性質探討;Self-assembly, Structure and Properties of Lanthanide Complexes with 1,2,4,5-Benzenetetracarboxylate
Authors:	余立中;Li-chung Yu
Contributors:	化學研究所
Keywords:	金屬有機配位聚合物;鑭系金屬;自組裝;MOFs;self-assembly;lanthanides
Date:	2010-07-23
Issue Date:	2010-12-08 14:17:35 (UTC+8)
Publisher:	國立中央大學
Abstract:	本文使用鑭系金屬離子和bezene-1,2,4,5-tetracarboxylic acid經由自組裝的方式合成出{[Sm2(btec)1.5(H2O)5]•10H2O}n (1)、{[Gd2(btec)1.5(H2O)5]•9H2O}n (2)、{[La2(btec)1.5(H2O)4]•3H2O}n (3) 、{[Ce2(btec)1(H2btec)1(H2O)4]•4H2O}n (4)、{[Gd(btec)0.5(H2btec)0.5(H2O)1]•2H2O}n (5)、{[Dy(btec)0.5(H2btec)0.5(H2O)1]•2H2O}n (6)、{[Ho(btec)0.5(H2btec)0.5(H2O)1]•2H2O}n (7)、{[Dy4(btec)3(H2O)8]•4H2O}n (8)、{[Ho4(btec)3(H2O)8]•4H2O}n (9)等九個化合物。化合物1、2具有相似的固態結構，是以九配位的金屬中心形成具有雙核金屬簇的三維結構，結構中有二維的通道。化合物3是以九配位及十配位的金屬中心形成具有四核金屬簇的三維結構，四核金屬簇是以四個金屬離子為頂點以氧橋連接形成四邊型的結構。化合物4是以九配位及十配位的金屬中心形成具有金屬鍊的二維結構，結構中苯四酸有兩種配位模式，其中最特別的是以使用1、5號位的羧酸基鍵結四個金屬離子，但保留了2、4號位置的羧酸基未鍵結任何金屬離子且羧酸基上的氫未脫去，形成文獻中未見的µ4-橋接配位模式。化合物5、6、7具有相似的固態結構，以九配位的金屬中心形成金屬鍊的三維結構。化合物8、9具有相似的固態結構，以八配位及九配位的金屬中心形成具有四核金屬簇的三維結構，四核金屬簇以Z字型的方式，以金屬為四個節點再以氧橋連接。以上化合物經由TGA鑑定，皆具有高的熱穩定性，達400∼500 ℃才開始崩塌瓦解。由直流磁化率χmT的數據及擬合中可知化合物5∼9整體的行為表現是反鐵磁性，但是由交流磁化率數據的虛數部分發現有磁緩現象，這是鑭系金屬化合物少見的磁性特質，此磁緩現象應是來自於結構中單一金屬離子或單一金屬鍊（簇）激發態所展現的行為。 A series of lanthanide complexes, {[Sm2(btec)1.5(H2O)5]•10H2O}n (1)、{[Gd2(btec)1.5(H2O)5]•9H2O}n (2)、{[La2(btec)1.5(H2O)4]•3H2O}n (3) 、{[Ce2(btec)1(H2btec)1(H2O)4]•4H2O}n (4)、{[Gd(btec)0.5(H2btec)0.5(H2O)1]•2H2O}n (5)、{[Dy(btec)0.5(H2btec)0.5(H2O)1]•2H2O}n (6)、{[Ho(btec)0.5(H2btec)0.5(H2O)1]•2H2O}n (7)、{[Dy4(btec)3(H2O)8]•4H2O}n (8)、{[Ho4(btec)3(H2O)8]•4H2O}n (9), were synthesized. The crystal structure diffraction analysis showed that complexes 1 and 2 are isostructure, and reveals a three-dimensional framework for the construction of two nine-coordinated metal centers. In the complexes 1 and 2, the two-dimensional channels are obtained. Complex 3 also shows a three-dimensional framework with the quadrilateral tetranuclear building units comprising of both ten- and nine-coordinated lanthanum centers. Complex 4 is a two-dimensional structure comprising of 1D cerium chain. The metal chains in the complex 4 are composed both of ten- and nine-coordinated cerium centers bridged by carboxylate groups of btec ligand. Complexes 5－7 show isostructural of three-dimensional frameworks constructing from lanthanide metal chains, which contains nine-coordinated metal centers bridged by carboxylate groups of btec ligand. The zigzag tetranuclear complexes 8－9 are also isostructure and display a three dimensional framework comprising of both nine- and eight-coordinated metal centers. The results of TGA studies indicated that complexes 1－8 are high thermal stability and their frameworks remain stable under heat treatment to 400－500 ℃. The magnetic results of complexes 5－9 indicate antiferromagnetic and spin-orbital coupling dominated between the metal ions in complexes 5－9. Surprisiely, slow magnetic relaxation was observed for complexes 6－9. The slow magnetic relaxation may be arise from the single-ion behavior of the metal ions or the exciting state of single metal chain rather than from the spin－spin coupling interaction between the metal ions.
Appears in Collections:	[Graduate Institute of Chemistry] Electronic Thesis & Dissertation

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