马来二腈基二硫烯镍(Ⅱ)配合物展现了介电反常和弛豫（英文）

A Bis(maleonitriledithiolato)nickelate Ion-Pair Compound Exhibiting Dielectric Anomaly and Relaxation

合成并用X-射线单晶衍射表征了一个离子对化合物1,7-bis(1-methylimidazolium)heptane bis(maleonitriodithiolato)nickelate(1)的结构。沿着晶体学c轴方向,化合物1中的阴、阳离子分别排列形成波浪形的链。变温介电性质研究表明,化合物1在90℃左右展现了介电态转变。我们将此转变归于化合物1中平衡阳离子的有序到无序转变。在低频区,化合物1出现了明显的介电弛豫过程,这与阳离子偶极运动有关。此外,DSC研究表明,在第二个升温过程中,化合物1在66℃和130℃左右出现两步冷结晶。此种冷结晶现象在小分子化合物中很罕见,这与化合物1的较大粘度以及测试过程中的较快降温速率有关。

An ion-pair compound, 1,7-bis（1-methylimidazolium）heptane bis（maleonitriodithiolato）nickelate （1）, was synthesized and single crystal structurally characterized. The bis （maleonitriodithiolato）nickelate anions and dication formed the wave-shape anion chain along c-axis direction, respectively. 1 undergoes a tunable transition at about 90 ℃ between high and low dielectric states at variable temperature, which probably arises from the order-to-disorder transformation of alkyl chains. The dielectric relaxation process in low-frequency region, attributed to the orientation polarization of the molecules dipoles, was observed and discussed. Furthermore, 1 exhibits cold crystallization around 66 ℃ and 130 ℃ during the second heating scan, and originated from fast cooling rate and the large viscosity. Such study provides a possible strategy to explore switchable dielectric material. CCDC： 1015809.