论文部分内容阅读
本文用一种新的方法对三个四核环状化合物Co_3Fe(mp)_4(Hmp)(PBu_3~n)_3(1)Co_4(mp)_4·(Hmp)(PMe_2Ph)_3(2)(H_2mp=2-巯基苯酚)和Co_4(mp)_4(PBu_3~n)_3Cl(MeOH)(3)进行了1.5～300K温度范围的磁性质研究,即在各向同性海森堡模型的基础上,用全矩阵对角化方法求自旋态能量本征值,从而得到化合物的磁化率,然后用阻尼最小二乘法拟合变温磁化率,得到磁交换常数.因避免了使用Kambe理论,无需对化合物进行模型简化处理,所以得到更多、更准确的磁交换信息.拟合结果显示三个化合物都呈较弱的磁偶合作用.对化合物1得到J_1=-3.14cm~(-1),J_2=-3.04cm~(-1),J_3=2.92cm~(-1)和J_4.08cm~(-1),对2得到J_1=-3.07cm~(-1),J_2=-3.19cm~(-1),J_3=-0.33cm~(-1)和J_4=-1.91cm~(-1);对3得到J_1=-4.818cm~(-1),J_2=-4.244cm~(-1),J_3=-1.164cm~(-1)和J_4=-2.634cm~(-1),其中J_1和J_2代表通过双重μ_2-S桥,J_3和J_4分别代表通过单重和双重μ2-O桥进行的磁交换作用常数.
In this paper, a new method for the determination of three tetranuclear cyclic compounds Co_3Fe (mp) _4 (Hmp) (PBu_3 ~ n) _3 (1) Co_4 (mp) _4 · (Hmp) (PMe_2Ph) _3 (2) = 2-mercaptophenol) and Co_4 (PB_3 ~ n) _3Cl (MeOH) (3) were studied in the temperature range of 1.5 ~ 300K, on the basis of the isotropic Heisenberg model, The whole matrix diagonalization method is used to find the eigenvalues of spin energy to obtain the magnetic susceptibility of the compound, then the temperature dependent magnetic susceptibility can be fitted by the damping least square method to obtain the magnetic exchange constant. Since the Kambe theory is avoided, Model was simplified, so more and more accurate magnetic exchange information was obtained. The fitting results showed that all three compounds showed weaker magnetic coupling. For compound 1, J_1 = -3.14cm -1, J_2 = - 3.04cm -1, J_3 = 2.92cm -1 and J_4.08cm -1, and J_1 = -3.07cm -1, J_2 = -3.19cm -1 ), J_3 = -0.33cm -1 and J_4 = -1.91cm -1, and J_1 = -4.818cm -1, J_2 = -4.244cm -1, J_3 = -1.164cm -1 and J_4 = -2.634cm -1, where J_1 and J_2 represent the magnetic fluxes of single μ and double μ2-O bridges through the double μ_2-S bridge, J_3 and J_4, respectively Exchange the role of constants.