Alcón I, Bromley S T
Department de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional, Universitat de Barcelona, C/Martí i Franquès 1, E-08028 Barcelona, Spain.
Phys Chem Chem Phys. 2018 Feb 14;20(7):5028-5035. doi: 10.1039/c7cp08076j.
Two-dimensional covalent networks based on triarylmethyl (TAM) radical monomers have been proposed as versatile materials whose unpaired electrons may be externally localised/delocalised through the application of external uniaxial strain. This phenomenon arises through the strain-induced variance of the dihedral twist angles of the aryl rings within the network, and allows the control of important physico-chemical properties (e.g. magnetic interactions, electronic band gap). In order to experimentally realise such materials, one must find a compromise between the kinetic stability of the TAM monomers (through sterically protecting the radical centre with the appropriate aryl ring functionalisation) and the structural flexibility of the resulting material (provided by low intra-ring steric hindrance). In this work, through an efficient search procedure based on force field-based screening, employing ∼1750 calculations, followed by selected accurate electronic structure calculations, we provide support for the experimental viability of TAM-based 2D networks with highly controllable properties.
基于三芳基甲基（TAM）自由基单体的二维共价网络已被提议作为通用材料，其未成对电子可通过施加外部单轴应变在外部进行局域化/离域化。这种现象是由于网络内芳基环二面角扭转角的应变诱导变化而产生的，并允许控制重要的物理化学性质（如磁相互作用、电子带隙）。为了通过实验实现这类材料，必须在TAM单体的动力学稳定性（通过用适当的芳基环官能团对自由基中心进行空间保护）和所得材料的结构灵活性（由低环内空间位阻提供）之间找到平衡。在这项工作中，通过基于力场筛选的高效搜索程序，进行了约1750次计算，随后进行了选定的精确电子结构计算，我们为具有高度可控性质的基于TAM的二维网络的实验可行性提供了支持。
