School of Chemistry and EaStChem, University of St Andrews, St Andrews, Fife, KY16 9ST (UK).
Angew Chem Int Ed Engl. 2015 Dec 14;54(51):15457-61. doi: 10.1002/anie.201506869. Epub 2015 Oct 30.
The ionothermal synthesis, structure, and magnetic susceptibility of a novel inorganic-organic hybrid material, imidazolium vanadium(III,IV) oxyfluoride [C3 H5 N2 ][V9 O6 F24 (H2 O)2 ] (ImVOF) are presented. The structure consists of inorganic vanadium oxyfluoride slabs with kagome layers of V(4+) S=${{ 1/2 }}$ ions separated by a mixed valence layer. These inorganic slabs are intercalated with imidazolium cations. Quinuclidinium (Q) and pyrazinium (Pyz) cations can also be incorporated into the hybrid structure type to give QVOF and PyzVOF analogues, respectively. The highly frustrated topology of the inorganic slabs, along with the quantum nature of the magnetism associated with V(4+) , means that these materials are excellent candidates to host exotic magnetic ground states, such as the highly sought quantum spin liquid. Magnetic susceptibility measurements of all samples suggest an absence of conventional long-range magnetic order down to 2 K despite considerable antiferromagnetic exchange.
本文报道了一种新型的无机-有机杂化材料咪唑鎓钒(III,IV)氧氟化物[C3 H5 N2 ][V9 O6 F24 (H2 O)2 ]（ImVOF）的离子热合成、结构和磁化率。该结构由具有 kagome 层的无机钒氧氟化物片层组成，V(4+) S=${{ 1/2 }}$ 离子分离由混合价层隔开。这些无机片层被咪唑鎓阳离子插层。喹诺利定（Q）和吡嗪鎓（Pyz）阳离子也可以掺入杂化结构类型中，分别得到 QVOF 和 PyzVOF 类似物。无机片层的高度受挫拓扑结构以及与 V(4+) 相关的磁性的量子性质意味着这些材料是宿主奇异磁基态的优秀候选者，例如高度追求的量子自旋液体。所有样品的磁化率测量表明，尽管存在相当大的反铁磁交换，但在 2 K 以下没有常规的长程磁有序。
