摘要
Two novel FeII spin crossover complexes [Fe(L1)3](BF4)25H2O (1) and [Fe(L2)3](BF4)2·2H2O (2) with 4-NHR-1,2,4-triazole (R = isopropyl, L1; cyclohexyl, L2) were synthesized. 1 and 2 remain white at room temperature, whereas they turn purple at liquid temperature. Variable temperature optical detection and magnetic susceptibilities measurement show that the spin-crossover phenomenon for 1 was observed between 120 K and 170 K. The hysteresis loop is about 10 K. The Tc temperature of 2 is 190 K, but no thermal hysteresis loop was found. The molar thermodynamic functions and the microscopic parameters were obtained from the theoretical analysis in terms of the domain model, two level Ising model and regular solution model, respectively.
Two novel FeII spin crossover complexes [Fe(L1)3](BF4)25H2O (1) and [Fe(L2)3](BF4)2·2H2O (2) with 4-NHR-1,2,4-triazole (R = isopropyl, L1; cyclohexyl, L2) were synthesized. 1 and 2 remain white at room temperature, whereas they turn purple at liquid temperature. Variable temperature optical detection and magnetic susceptibilities measurement show that the spin-crossover phenomenon for 1 was observed between 120 K and 170 K. The hysteresis loop is about 10 K. The Tc temperature of 2 is 190 K, but no thermal hysteresis loop was found. The molar thermodynamic functions and the microscopic parameters were obtained from the theoretical analysis in terms of the domain model, two level Ising model and regular solution model, respectively.
作者
DING Bin, WANG Hongmei, YI Long, CHENG Peng, LI Licun, ZHAI Yuping, LIAO Daizheng, YAN Shiping & JIANG Zonghui Department of Chemistry, Nankai University, Tianjin 300071, China Correspondence should be addressed to Cheng Peng or Liao Daizheng (e-mail: pcheng@nankai.edu.cn)
基金
supported by the National Natural Science Foundation of China(Grant Nos.90101028,50173011 and 50172021)
the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions of MOE,China.
关键词
热力学性质
铁
磁化系数
磁滋环
旋转截面化合物
记忆功能
FeⅡ complexes, spin crossover, triazole, variable temperature magnetic susceptibilities, hysteresis loop.
