A homoleptic, self-assembled [2 x 2] square Cu4 complex exhibiting intramolecular ferromagnetic exchange

被引:35
作者
Xu, ZQ [1 ]
Thompson, LK [1 ]
Miller, DO [1 ]
机构
[1] Mem Univ Newfoundland, Dept Chem, St John, NF A1B 3X7, Canada
来源
JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS | 2002年 / 12期
关键词
D O I
10.1039/b201076n
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
A carboxylic acid-substituted picolinic hydrazone ligand (pcoap) forms a homoleptic [2 x 2] tetranuclear Cu(II)(4) complex with four six-coordinate Cu(II) centers bridged by mu-O alkoxide groups in a square grid structure. The terminal carboxylic groups complete the six-coordinate structures at each copper centre, capping off external coordination positions, with two functioning as carboxylates, and two in neutral carboxylic acid form. Despite very large Cu-O-Cu bridge angles (139.2-140.6degrees), and short Cu-Cu distances (3.97-4.05 Angstrom), which would normally be expected to propagate antiferromagnetic exchange interactions within the grid, strictly orthogonal bridging connections between the metal centers lead to intramolecular ferromagnetic exchange (J = 7.2(3) cm(-1)), and an S = 4/2 magnetic ground state.
引用
收藏
页码:2462 / 2466
页数:5
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