不同异构型的双铜配合物的结构、磁性和分子力学研究

Structural, Magnetic and Molecular Mechanics Studies on Dicopper(II) Complexes with Different Tautomers

以2,6-二甲酰-4-甲基苯酚双缩苯甲酰肼(H_3L)为双核配体,合成并表征了外源桥为N_3^-的酮式双铜配合物[Cu_2(H_2L)(μ-N_3)](ClO_4)_2·1/2C_2H_5OH(1)和酮醇混合式双铜配合物[Cu_2(HL)(μ-N_3)(ClO_4)(C_2H_5OH)(H_2O)](2).2的晶体属于单斜晶系,空间群P2_1/c,晶胞参数:a=1.0967(4),b=0.7684(2),c=3.5724(7)nm;β=90.08(2)°;V=3.0103nm^3,Z=4,D_c=1.61g/cm^3;μ=15.66cm^(-1),F(000)=1488.最终的偏差因子R=0.083和R_w=0.088.对配合物在4～300K的磁化率数据分析表明,铜离子间存在中等强度的反铁磁相互作用,交换参数(2J)分别为-86.8cm^(-1)(1)和-132.4cm^(-1)(2).本文兼用分子力学和量子化学计算讨论了互变异构体对磁交换作用的影响.

Two dicopper(II) complexes, [Cu2 (H2L) (μ - N3 ) ] (ClO4)2 1/2C2H5OH (1) and[Cu2(HL)(μ- N3)(ClO4)(C2H5OH)(H2O)] (2), have been synthesized and characterized, where H3L is the binucleating ligand 2,6 - diformyl - 4 - methylphenol di(benzoylhydrazone). The crystal structure of 2 has been determined. Crystal data for 2 are monoclinic, space groupP21/c, a = 1.0967(4) nm, b = 0. 7684(2)nm, c = 3. 5724(7) nm, β=90.08(2)°, V = 3.0103nm3, Z=4, Dc = 1. 61g·cm-3, μ= 15. 66cm-1, F(000) = 1488. The final R and Rw values are 0. 083 and 0. 088, respectively. The analysis of variable - temperature (4~300K) magnetic susceptibility data indicates that a medium antiferromagnetic interaction occured between copper(II) ions. The exchange parameters (2J) are - 86. 8cm-1 for 1 and - 132. 4 cm-1 for 2, respectively. The effect of tautomeric isomeride on magnetic interaction was discussed by molecular mechanics and CNDO/2 methods.