双核镍(Ⅱ)配合物的合成、晶体结构和磁性质

Synthesis, Crystal Structure and Magnetic Properties of Dinuclear Nickel(Ⅱ) Complex

合成了通过N-N键桥联的不对称的N2O3席夫碱配体(H3L)的镍髤配合物[Ni2(HL)2]2(DMF)8(H2O)2(1)。配合物晶体属于三斜晶系,空间群为P1,a=1.2735(2)nm,b=1.3604(3)nm,c=1.4276(3)nm,α=85.358(4)°,β=63.513(3)°,γ=79.545(4)°,V=2.1768(7)nm3,Z=1,F(000)=980,R1=0.0736。配合物1的不对称单元中含有两个双核结构Ni2(HL)2(DMF)2(H2O)2(Ⅰ)和Ni2(HL)2(DMF)4(Ⅱ)以及两个DMF溶剂分子。通过酚基氧原子桥联的镍-镍距离分别为:Ni(1)-Ni(1A),0.3084nm;Ni(2)-Ni(2B),0.3103nm(对称操作:A:1-x,2-y,-z;B:1-x,1-y,1-z)。金属镍髤离子采取扭曲的八面体配位构型,一个配体的NO2三齿配位单元和另一个配体的酚基氧原子位于赤道面位置,两个溶剂分子占据轴向位置。晶体中存在着分子内以及分子与溶剂分子间的两种氢键作用。配合物1的变温磁化率测定表明,Ni髤离子之间的反铁磁耦合作用在它的磁性质中起主导作用。

Asymmetrical pentadentate Schiff-base ligand H3L with two coordination compartments linked by a single N-N bridge and its nickel(Ⅱ) complex [Ni2(HL)2]2(DMF)8(H2O)2 (1) have been synthesized. Crystal data: triclinic, space group P1, a=1.273 5(2) nm, b=1.360 4(3) nm, c=1.427 6(3) nm, α=85.358(4)°, β=63.513(3)°, γ=79.545(4)°, V=2.176 8(7) nm3, Z=1, F(000)=980, R1=0.073 6 for 5 475 observed reflections [I≥2σ(I)]. An asymmetric unit of complex 1 comprises two binuclear structures Ni2(HL)2(DMF)2(H2O)2 (Ⅰ) and Ni2(HL)2(DMF)4 (Ⅱ) and two DMF solvent molecules. The separations of phenol oxygen bridged nickel(Ⅱ) centers Ni(1)-Ni(1A) and Ni(2)-Ni(2B) are 0.308 4 and 0.310 3 nm, respectively (symmetry code: A: 1-x, 2-y, -z; B: 1-x, 1-y, 1-z). The metal centers in the distorted octahedral geometries were coordinated by a NO2 tridentate moiety from one ligand, a phenyl oxygen atom from another ligand and two oxygen atoms of different solvent molecules. There are two type hydrogen bonds in the crystal. The magnetic behavior of complex 1 indicates that the antiferromagnetic exchange coupling between Ni(Ⅱ) ions dominates the magnetic properties of the complex. CCDC: 273546.