Yang Hao, Cheng Tao, Goddard William A, Ren Xiao-Ming
State Key Laboratory of Materials-Oriented Chemical Engineering and College of Chemistry and Molecular Engineering , Nanjing Tech University , Nanjing 211816 , People's Republic of China.
Materials and Process Simulation Center , California Institute of Technology , Pasadena , California 91125 , United States.
J Phys Chem Lett. 2019 Nov 7;10(21):6432-6437. doi: 10.1021/acs.jpclett.9b02219. Epub 2019 Oct 9.
Planar bis-1,2-dithiolene complex anions of a transition metal (denoted as [M(dithiolato)] and M = Ni, Pd, or Pt ion) favor forming columnar stacks of anions in the crystal that feature S = 1/2 spin-chains, and such a spin-chain compound often undergoes a spin-Peierls-type transition, making this a promising material for conducting and magnetic switching. However, current examples show the transition temperatures are far too low for most applications. We use quantum mechanics to predict that changing the cation arrangement from the boat-type to the chair-type packing configuration in a spin-Peierls-type [Ni(dithiolato)] complex will substantially stabilize the antiferromagnetic coupling, dramatically increasing the transition temperature. We estimate that the [Ni(mnt)]-based complexes (mnt = maleonitriledithiolate) with chair-type packing of cations will lead to critical temperatures of ∼170, ∼252, and ∼310 K for S-, Se-, and Te-based mnt, respectively. We also suggest how to stabilize the chair-type configurations of these systems.
过渡金属的平面双 - 1,2 - 二硫烯配合物阴离子（表示为[M(dithiolato)]，其中M = Ni、Pd或Pt离子）在晶体中倾向于形成阴离子的柱状堆积，其特征为具有S = 1/2的自旋链，并且这种自旋链化合物通常会经历自旋 - 派尔斯型转变，使其成为用于导电和磁开关的有前途的材料。然而，目前的例子表明，对于大多数应用而言，转变温度过低。我们用量子力学预测，在自旋 - 派尔斯型[Ni(dithiolato)]配合物中，将阳离子排列从船型改变为椅型堆积构型将极大地稳定反铁磁耦合，显著提高转变温度。我们估计，对于基于S - 、Se - 和Te - 的mnt（mnt = 马来二腈二硫醇盐），具有阳离子椅型堆积的[Ni(mnt)]基配合物的临界温度分别约为170 K、252 K和310 K。我们还提出了如何稳定这些体系的椅型构型。
