新型二维草酸根桥联配合物{[Cu(en)_2]_4[KFe(C_2O_4)_3]_4}_n的合成、结构和磁性

A Novel Two - Dimensional Oxalate - Bridged Complex {[ Cu (en)_ 2 ]_ 4 [ KFe~Ⅲ (C_2O_4) _3 ]_ 4}_n Synthesis, Structure and Magnetic Properties

合成了一个新型草酸根桥联的二维配合物{[Cu(en)_2]_4[KFe(C_2O_4)_3]_4}_n,并进行了晶体结构测试和磁性研究.晶体结构分析显示:K^+离子为罕见的八配位环境,2个C_2O_4^(2-)和2个或1个K^+离子长程桥联2个Fe~Ⅲ离子,形成一个二维网状的[KFe(C_2O_4)_3]_n^(2n-)骨架,[Cu(en)_2]^(2+)单元通过(en)N—H…O(C_2O_4)氢键与[KFe(C_2O_4)_3]_n^(2n-)骨架连接.变温磁化率测量表明:Fe~Ⅲ与Fe~Ⅲ间存在着弱的磁相互作用,J=-0.17cm^(-1).

A novel two - dimensional oxalate - bridged complex {[Cu(en)2]4[ KFe ( C2O4 )3 ]4 }n has been synthesized and structurally and magnetically characterized. In this complex the eight - coordinate environment of K + ions leads to a unique structural arrangement with two C2O42- bridges and two or one K+ ion linking pairs of FeIII ions. As a consequence, a novel 2D [ KFe( C2O4)3 ]n2n- network forms. Another feature of the structure is the presence of hydrogen bonding connecting the Cu(en)22+ entities and [KFe(C2O4)3]n2n- network through (en)N-H…O(C2O4) . The magnetic susceptibility data good fits to the experimental data from room temperature to 4.2K were obtained for J = - 0.17cm-1.