不对称四核环状Co3^IIM^II簇合物的磁化学

本文用一种新的方法对三个核环状化合物Co3Fe(mp)4(Hmp)(PBu3^n)3(1) Co4(mp)4(Hmp)(PMe2Ph)3(2)(H2mp=2-巯基苯酚)和Co4(mp)4(PBu3^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, 无须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J1=-3.14cm^-^1, J2=-3.04cm^-^1, J3=2.92cm^-^1和J4=4.08cm^-^1, 对2得到J1=-3.07cm^-^1, J2=-3.19cm^-^1,J3=-0.33cm^-^1和J4=-1.91cm^-^1; 对3得到J1=-4.818cm^-^1,J2=-4.244cm^-^1, J3=-1.164cm^-^1和J4=-2.634cm^-^1, 其中J1和J2代表通过双重μ2-S桥, J3和J4分别代表通过单重和双重μ2-O桥进行的磁交换作用常数。

Magnetic chemistry of tetranuclear Co3^IIM^II complexes

Magnetic properties of three tetranuclear complexes Co3Fe(mp)4(Hmp)(PBu3^n)3(1) Co4(mp)4(Hmp)(PMe2Ph)3(2) and Co4(mp)4(PBu3^n)3Cl(MeOH)(3) have been studied in the temperature range of 1.5-300K. On the basis of isotropic Heisenberg model, the eigenvalues for the possible spin states were obtained with the full-matrix diagonalisation method and variable-temperature magnetic susceptibilities were fitted by the least-squares calculation. The fitting results show J1=-3.14cm^-^1, J2=-3.04cm^-^1, J3=2.92cm^-^1 and J4=4.08cm^-^1 for 1; J1=-3.07cm^-^1, J2=-3.19cm^-^1, J3=-0.33cm^-^1 and J4=-1.91cm^-^1 for 2; J1=-4.818cm^-^1, J2=-4.244cm^-^1, J3=-1.164cm^-^1 and J4=-2.634cm^-^1 for3, where J1 and J2 are the exchange coupling constants transmitted by two μ2-S bridges, J3 and J4 by one μ2-O and two μ2-O bridges, respectively.