Unusual spin gap transition observed in two new molecular magnets based on [Ni(mnt)(2)](-) monoanion (mnt(2-) = maleonitriledithiolate)

作者：Zuo Hong rong; Huang Qian; Huang Chun yan; Huang Dong hai; Hou Yong; Yang Le min; Ni Chun lin^*; Meng Qing jin

来源：Journal of Solid State Chemistry, 2009, 182(1): 147-152.

DOI：10.1016/j.jssc.2008.10.014

• Bis(maleonitriledithiolato)nickelate monoanion
• Molecular magnet
• Substituted benzyl-4-dimetylaminopyridinium
• Crystal structures
• Spin gap transition

Two new molecular magnets, [RBzPyN(CH3)(2)][Ni(mnt)(2)] [mnt(2-) = maleonitrileclithiolate; [RBzPyN(CH3)(2)](+) =1-(4'-R-benzyl)-4-dimethylaminopyridinium; R = CN(1), F(2)], with unusual magnetic properties have been prepared and characterized. Both 1 and 2 form a 3D network structure in which the [Ni(mnt)(2)](-) anions form a 1D magnetic chain for 1 and a stepwise stack for 2 via weak pi center dot center dot center dot pi stacking interactions, C center dot center dot center dot C or C center dot center dot center dot N short interactions between the neighboring anions. Magnetic susceptibility measurements in the temperature range 1.8-300K indicated that 1 and 2 show unusual spin gap transition around 30 K and 110 K, respectively. The transition for 1 and 2 is the second-order phase transition as determined by the capacity measurement.

• 单位
  中国农业大学; 南京大学; 华南农业大学