Pseudohalide-bridged five-coordinate Ni(II) or Co(II) complexes with bulky bidentate ligands : Magneto-structural correlationship
Pseudohalide-bridged five-coordinate Ni(II) or Co(II) complexes with bulky bidentate ligands : Magneto-structural correlationship
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DOI：
10.1016/j.ica.2007.12.018
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发表时间：
2008-06
影响因子：
2.8
通讯作者：
H. Kou;Shoko Hishiya;O. Sato
中科院分区：
文献类型：
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作者：
H. Kou;Shoko Hishiya;O. Sato
2，2 ′-联喹啉（biq）和6，6 ′-二甲基-2，2 ′-联吡啶（dmbpy）在氮原子的顺式位阻取代基的双齿配体已被用于过渡金属配合物的合成。合成了六个新的双端叠氮桥联双核配合物[M2（biq）2（μ 1，1-N3）2（N3）2]（M=Ni（1），M=Co（2）），[M2（biq）2（μ 1，1-N3）2Cl 2]（M=Ni（3），M=Co（4）），[M2（dmbpy）2（μ 1，1-N3）2（N3）2]（M=Ni（5），M=Co（6））和一种端-端硫氰酸根桥联的聚合物[Ni（dmbpy）（μ 1，3-SCN）（NCS）]n（7），并通过单晶X射线衍射和磁性研究对其进行了表征。配合物1-6包含由两个末端叠氮化物配体桥接的五配位M（II）离子。桥连M-N-M键角在104.1-105.2°之间。配合物7由一个单硫氰酸根桥联的Ni（II）链组成，其中Ni（II）离子是五配位的。研究表明，大体积配体在五配位结构的形成中起着关键作用。所有配合物显示分子内金属间铁磁耦合与JNiNi和JCoCoof约。根据哈密顿量H^=-2JS^1S^2（对于Ni 2，S1 =S2=1;对于Co 2，S2 = 3/2），可以得到23或13 cm − 1。单SCN−桥链状配合物7具有链内铁磁相互作用，J=3.96（2）cm− 1，D=−4.55（8）cm−1（H^=-2J i =1（S iS^i+1）-D∑i=1[（S^iZ）2-2/3]）.研究了磁结构相关性。
Bidentate ligands 2,2′-biquinoline (biq) and 6,6′-dimethyl-2,2′-bipyridine (dmbpy) with steric hindrance substituents cis to the nitrogen atoms have been used in the synthesis of transition metal complexes. Six new doubly end-on azido-bridged binuclear complexes [M2(biq)2(μ1,1-N3)2(N3)2] (M=Ni (1), M=Co (2)), [M2(biq)2(μ1,1-N3)2Cl2] (M=Ni (3), M=Co (4)), [M2(dmbpy)2(μ1,1-N3)2(N3)2] (M=Ni (5), M=Co (6)) and one end-to-end thiocyanato-bridged polymeric [Ni(dmbpy)(μ1,3-SCN)(NCS)]n(7) have been synthesized and characterized by single crystal X-ray diffraction analysis and magnetic studies. Complexes 1–6 comprise five-coordinate M(II) ions bridged by two end-on azide ligands. The bridging M–N–M bond angles are in the small range 104.1–105.2°. Complex 7 consists of a singly thiocyanate-bridged Ni(II) chain in which Ni(II) ions are five-coordinate. This research suggests that the bulky ligands play a key role in the formation of five-coordinate coordination structure. All complexes display intramolecular intermetallic ferromagnetic coupling with JNiNiand JCoCoof ca. 23 or 13cm−1based on the Hamiltonian H^=-2JS^1S^2(S1=S2=1 for Ni2, or 3/2 for Co2). The singly SCN−-bridged chainlike complex 7 shows intrachain ferromagnetic interaction with J=3.96(2)cm−1and D=−4.55(8)cm−1(H^=-2J∑i=1(SˆiS^i+1)-D∑i=1[(S^iZ)2-2/3]). Magneto-structural correlationship has been investigated.