新型氰基桥联二维配位聚合物{[Fe(salen)]_2[Ni(CN)_4]}_n的合成、晶体结构和磁性质

Synthesis, Crystal Structure and Magnetic Properties of a Cyano-bridged Two-dimensional Coordination Polymer｛[Fe(salen)]_2[Ni(CN)_4]｝_n

将 [Fe(salen)NO3]的甲醇溶液和K2 [Ni(CN) 4 ]·H2 O的水溶液通过H管扩散反应 ,得到了一个新型氰基桥联配位聚合物 { [Fe(salen) ] 2 [Ni(CN) 4 ] } n(H2 salen为N ,N′ 二水杨醛缩乙二胺席夫碱 ) .该化合物属四方晶系 ,空间群P4/ncc,晶胞参数为a =b =1.42 16(2 )nm ,c =1.7471(5)nm ,V =3 53 0 8(12 )nm3,Z =4.该配合物通过Ni—CN—Fe(salen)—NC—Ni链连接形成二维枕形网格结构 ,其中键长Ni—C 0 .1876(3 )nm ,Fe—N 0 .2 170 (3 )nm ,键角Fe—N—C 164.9(3 )°,Ni—C—N178.9(4)° ;金属中心Ni(Ⅱ )和Fe(Ⅲ )分别具有正方形和畸变八面体配位构型 .变温磁化率研究表明 ,配合物存在分子内反铁磁相互作用 ,其Fe(Ⅲ )···Fe(Ⅲ )交换积分为 -0 .0 41cm-

A cyano-bridged coordination polymer, {[Fe(salen)](2)[Ni(CN)(4)]}(n) (salen = N, N'-ethylenebis-(salicylideneimi-nato)-dianion), prepared by slow diffusion of an aqueous solution of K-2[Ni(CN)(4)].H2O and a MeOH solution of [Fe(salen)-NO3] in an H tube, has been characterized by X-ray structure analysis, IR spectra and magnetic measurements. The complex crystallizes in the tetragonal space group P4/ncc with a = b = 1.4216(2) rim, c = 1.7471 (5) nm, V = 3.5308 ( 12) nm(3), Z = 4. The product assumes a two-dimensional network structure consisting of pillow-like octanuclear [-Ni-CN-Fe(salen)-NC-](4) units with dimensions: Ni-C = 0.1876(3) nm, Fe-N = 0.2170(3) nm, Fe-N-C = 164.9(3)degrees, Ni-C-N = 178.9(4)degrees. The two metal atoms Ni(II) and Fe(III) have square and slightly distorted octahedral arrangements, respectively. The variable temperature magnetic susceptibility, measured in the 5 similar to 300 K range, indicates the presence of a weak intralayer antiferromagnetic interaction and gives an Fe(III)...Fe (III) exchange integral of -0.041 cm(-1).