双臂套索冠醚双核铜(Ⅱ)配合物的磁性质研究

Studies on the Magnetic Properties of Binuclear Copper(Ⅱ) Complex of a Bibracchial Lariat Ether

测定了双臂套索冠醚双核铜（Ⅱ）配合物［Ｃｕ２Ｌ（ＯＨ）］（ＣｌＯ４）３Ｍｅ２ＣＯ（Ｌ＝Ｎ，Ｎ′－二（８－喹啉甲基）－１，４，１０，１３－四氧－７，１６－二氮环八环）的变温磁化率（４～３００Ｋ），所加场强为５．０×１０５Ａ／ｍ．拟合了变温磁化率数据，得到Ｊ＝－２７９．４ｃｍ－１；加上分子场校正后，得Ｊ＝－２５７．７ｃｍ－１，Ｚｊ′＝－３０．１ｃｍ－１．拟合结果表明，分子间存在反铁磁性交换作用，而分子内的磁交换（Ｊ＜５００ｃｍ－１）还未大到使其反铁磁性交换作用变为抗磁性．用自旋倾斜体系解释了其反常的χｍ－Ｈ图．晶体结构和Ｃｕ２＋３ｄ轨道的分析表明，磁交换作用是通过ＯＨ桥进行的．比较了另外２个类似的双核铜（Ⅱ）大环ＯＨ桥联配合物。

The variable temperature(4￣300 K) magnetic susceptibility of binuclear copper(Ⅱ) complex of the bibracchial lariat ether Cu 2L(OH) (ClO 4) 3Me 2CO(L= N,N ′ bis(8 quinolylmethyl) 1,4,10,13 tetraoxa 7,16 diazacyclooctadecane) (1) was measured in an appropriate magnetic field of 500 000 A/m. The strongly antiferromagnetic interaction constants are as follows: J =-257.7 cm -1 , Zj′ =-30.1 cm -1 . It is shown that there is an antiferromagnetic interaction between molecules. The | J | value (<500 cm -1 ) is not large enough to lead to the diamagnetic coupling. The plot of χ m H , which is different from the normal plot of χ m H , is explained through the spin canting phenomenon. By analyzing the crystal structure of the complex and 3 d orbitals of two Cu 2+ cations, we suggest that the exchange path is through OH bridge. Compared with the other two analogous binuclear copper(Ⅱ) complexes coordinated by macrocycle ligand and bridged by OH, we analyzed the correlation between J value and the overlap of orbitals.