Manson Jamie L, Brambleby Jamie, Goddard Paul A, Spurgeon Peter M, Villa Jacqueline A, Liu Junjie, Ghannadzadeh Saman, Foronda Francesca, Singleton John, Lancaster Tom, Clark Stewart J, Thomas Iorwerth O, Xiao Fan, Williams Robert C, Pratt Francis L, Blundell Stephen J, Topping Craig V, Baines Christopher, Campana Charles, Noll Bruce
Department of Chemistry and Biochemistry, Eastern Washington University, Cheney, WA, 99004, United States.
Department of Physics, University of Warwick, Coventry, CV4 7AL, United Kingdom.
Sci Rep. 2018 Mar 16;8(1):4745. doi: 10.1038/s41598-018-23054-6.
Strong hydrogen bonds such as F···H···F offer new strategies to fabricate molecular architectures exhibiting novel structures and properties. Along these lines and, to potentially realize hydrogen-bond mediated superexchange interactions in a frustrated material, we synthesized [HF][NiF(Fpy)][SbF] (Fpy = 3-fluoropyridine). It was found that positionally-disordered HF ions link neutral NiF(Fpy) moieties into a kagome lattice with perfect 3-fold rotational symmetry. Detailed magnetic investigations combined with density-functional theory (DFT) revealed weak antiferromagnetic interactions (J ~ 0.4 K) and a large positive-D of 8.3 K with m = 0 lying below m = ±1. The observed weak magnetic coupling is attributed to bond-disorder of the HF ions which leads to disrupted Ni-F···H-F-H···F-Ni exchange pathways. Despite this result, we argue that networks such as this may be a way forward in designing tunable materials with varying degrees of frustration.
诸如F···H···F这样的强氢键为构建具有新颖结构和性质的分子结构提供了新策略。沿着这些思路，并且为了在一种受挫材料中潜在地实现氢键介导的超交换相互作用，我们合成了[HF][NiF(Fpy)][SbF]（Fpy = 3-氟吡啶）。结果发现，位置无序的HF离子将中性的NiF(Fpy)部分连接成具有完美三重旋转对称性的 Kagome 晶格。结合密度泛函理论（DFT）的详细磁性研究表明存在弱反铁磁相互作用（J ~ 0.4 K）以及m = 0低于m = ±1时8.3 K的大正D值。观察到的弱磁耦合归因于HF离子的键无序，这导致Ni-F···H-F-H···F-Ni交换路径中断。尽管有这个结果，但我们认为这样的网络可能是设计具有不同程度受挫的可调谐材料的一条前进道路。
