两种马来二腈基二硫烯镍(Ⅲ)近红外吸收配合物的结构、磁和电化学性质

Crystal Structure, Magnetic, Near-Infrared Absorption and Electrochemical Properties of Two [Ni(mnt)_2]^- Based Compounds

合成并表征了两种新的离子对化合物(BMIB)[(Ni(mnt)2]2(1)和(BMIO)[(Ni(mnt)2)]2(2)(其中mnt2-=马来二氰基二硫烯,BMIB=1,4-bis(1-methylimidazolium)butane,BMIO=1,8-bis(1-methylimidazolium)octane)。在化合物1中,[Ni(mnt)2]-阴离子排列形成阴离子三聚体以及与阳离子交替排列形成阴、阳离子混合柱。化合物2的堆积结构与化合物1不同,阴、阳离子堆积成非等间距的阴、阳离子柱。化合物1和2分别在861和857 nm近红外波段处出现较强的近红外吸收。电化学性质研究结果表明,2个化合物均出现了两对不可逆的电化学氧化/还原过程,且平衡阳离子的烷基链长显著影响化合物的氧化、还原电极电势。变温磁化率测量表明,在2～400 K温度范围内,化合物1表现出弱的顺磁性质,变温摩尔磁化率遵循简单的Curie-Weiss定律。化合物2表现出低维反铁磁交换自旋体系磁化率特征。

Two ion-pair compounds with the formula of （BMIB）[（Ni（mnt）2]2 （1） and （BMIO）[（Ni（mnt）2]2 （2） （rant= maleonitrile dithiolate, BMIB=1,4-bis（1-methylimidazolium）butane, BMIO=1,8-bis（1-methylimidazolium）octane） were synthesized and characterized structurally. In 1, the [Ni（mnt）2]- form a trimer anions and a mixed column, respectively. The packing structures of 2 are different from 1, the cations and the anions form the irregular alignments. Compound 1 and 2 show remarkable near-IR absorption behavior in the region of 861 and 857 nm respectively. The electrochemical behaviors in the solid state depend on the hydrocarbon chain length in the countercation moiety. Investigations of variable-temperature magnetic susceptibility indicated that 1 shows weak paramagnetic feature from 2 to 400 K; the magnetic susceptibility data were fit to the Curie-Weiss equation. 2 is a spin gap system but its magnetic behavior does not follow the Blaney-Bowers spin dimer model. CCDC： 908109, 1; 908110, 2.