A new ionic pair salt[Ni(bpy)3][Ni(mnt)2]2(mnt=1,2-dicyanoethane-1,2-dithiolate)has been prepared and its crystal structure was determined by X-ray crystallography at 293,200 and 100 K.In the mononuclear radical anion...A new ionic pair salt[Ni(bpy)3][Ni(mnt)2]2(mnt=1,2-dicyanoethane-1,2-dithiolate)has been prepared and its crystal structure was determined by X-ray crystallography at 293,200 and 100 K.In the mononuclear radical anionic complex,the nickel ion assumes a slightly distorted square-planar geometry.There is a special kind of stacking interactions at each temperature(i.e.,Model A at 293 K,Model B at 200 K and Model C at 100 K).The variable-temperature magnetic moments indicate that there is a strong anti-ferromagnetic interaction between the adjacent p-p stacking mononuclear radical anionic complexes and especially the anti-ferromagnetic coupling strength is close to the diamagnetism at 100 K.The theoretical calculations reveal for the first time that the spin densities between the short contact atoms areβstate and the anti-ferromagnetic coupling property of this crystal may be related to theβstate spin densities between the short contact atoms.The theoretical calculations further confirm that the strong anti-ferromagnetic coupling strength should be relevant to the larger spin densities on the short contact atoms and the larger overlap integrals between the short contact atoms.展开更多
Two two-dimensional coordination polymers, [Cd（μ1,3-SCN-）2（μ1,6-L）]n 1 and [Co（μ1,3-SCN-）2（μ1,6-L）]n 2, have been synthesized with 2,3-dimethylpyrazine-1,4-dioxide （L） and thiocyanate as mixed bridging l...Two two-dimensional coordination polymers, [Cd（μ1,3-SCN-）2（μ1,6-L）]n 1 and [Co（μ1,3-SCN-）2（μ1,6-L）]n 2, have been synthesized with 2,3-dimethylpyrazine-1,4-dioxide （L） and thiocyanate as mixed bridging ligands, and their crystal structures were determined by X-ray crystallography. Both crystals belong to monoclinic system, space group C2/c. The other crystal parameters are as follows： for complex 1： α = 9.732（3）, b =14.658（5）, c = 8.811（3） A, β = 102.935（4）°, Z = 4, V= 1225.1（7） A^3, C8H8CdN4O2S2, Mr = 368.71, Dc = 1.999 g/cm^3, F（000） = 720 and μ= 2.117 mm^-1; for complex 2： α = 9.528（7）, b = 14.563（11）, c = 8.415（6） A, β= 102.195（9）°, V= 1141.3（14） A^3, Z = 4, C8H8CoN4O2S2, Mr = 315.23, Dc = 1.835 g/cm^3, F（000） = 636 and μ = 1.863 mm^-1. The two complexes show similar two-dimensional sheet structures. Along the c axis one-dimensional chains are constructed by the coordination of Cd（Ⅱ） （or Co（Ⅱ）） ions with μ1,6-L bridging ligand, and the μ1,3-SCN- bridging ligands make the chains connect to each other, resulting in the formation of a two-dimensional sheet on the ac plane.展开更多
基金supported by the National Natural Science Foundation of China(No.20971080)
文摘A new ionic pair salt[Ni(bpy)3][Ni(mnt)2]2(mnt=1,2-dicyanoethane-1,2-dithiolate)has been prepared and its crystal structure was determined by X-ray crystallography at 293,200 and 100 K.In the mononuclear radical anionic complex,the nickel ion assumes a slightly distorted square-planar geometry.There is a special kind of stacking interactions at each temperature(i.e.,Model A at 293 K,Model B at 200 K and Model C at 100 K).The variable-temperature magnetic moments indicate that there is a strong anti-ferromagnetic interaction between the adjacent p-p stacking mononuclear radical anionic complexes and especially the anti-ferromagnetic coupling strength is close to the diamagnetism at 100 K.The theoretical calculations reveal for the first time that the spin densities between the short contact atoms areβstate and the anti-ferromagnetic coupling property of this crystal may be related to theβstate spin densities between the short contact atoms.The theoretical calculations further confirm that the strong anti-ferromagnetic coupling strength should be relevant to the larger spin densities on the short contact atoms and the larger overlap integrals between the short contact atoms.
基金This work was supported by the National Natural Science Foundation of China (No. 20271043) and the Natural Science Foundation of Shandong Province (Y2005B25)
文摘Two two-dimensional coordination polymers, [Cd（μ1,3-SCN-）2（μ1,6-L）]n 1 and [Co（μ1,3-SCN-）2（μ1,6-L）]n 2, have been synthesized with 2,3-dimethylpyrazine-1,4-dioxide （L） and thiocyanate as mixed bridging ligands, and their crystal structures were determined by X-ray crystallography. Both crystals belong to monoclinic system, space group C2/c. The other crystal parameters are as follows： for complex 1： α = 9.732（3）, b =14.658（5）, c = 8.811（3） A, β = 102.935（4）°, Z = 4, V= 1225.1（7） A^3, C8H8CdN4O2S2, Mr = 368.71, Dc = 1.999 g/cm^3, F（000） = 720 and μ= 2.117 mm^-1; for complex 2： α = 9.528（7）, b = 14.563（11）, c = 8.415（6） A, β= 102.195（9）°, V= 1141.3（14） A^3, Z = 4, C8H8CoN4O2S2, Mr = 315.23, Dc = 1.835 g/cm^3, F（000） = 636 and μ = 1.863 mm^-1. The two complexes show similar two-dimensional sheet structures. Along the c axis one-dimensional chains are constructed by the coordination of Cd（Ⅱ） （or Co（Ⅱ）） ions with μ1,6-L bridging ligand, and the μ1,3-SCN- bridging ligands make the chains connect to each other, resulting in the formation of a two-dimensional sheet on the ac plane.
