Department of Physics & Astronomy, State University of New York, Stony Brook, NY, 11794-380, USA.
Current Address: X-ray Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA.
Chemistry. 2019 Feb 1;25(7):1752-1757. doi: 10.1002/chem.201804935. Epub 2019 Jan 8.
The reaction of Mn (O CMe) and NaCN or LiCN in water forms a light green insoluble material. Structural solution and Rietveld refinement of high-resolution synchrotron powder diffraction data for this unprecedented, complicated compound of previously unknown composition revealed a new alkali-free ordered structural motif with [Mn (μ -OH) ] cubes and octahedral [Mn (CN) ] ions interconnected in 3D by Mn -N≡C-Mn linkages. The composition is {[Mn (OH ) ][Mn (OH )] }(μ -OH) ][Mn (μ-CN) (CN) ]⋅H O=[Mn (μ -OH) (OH ) ][Mn (μ-CN) (CN) ]⋅H O, which is further simplified to [Mn (OH) ]Mn(CN) (1). 1 has four high-spin (S=5/2) Mn sites that are antiferromagnetically coupled within the cube and are antiferromagnetically coupled to six low-spin (S=1/2) octahedral [Mn (CN) ] ions. Above 40 K the magnetic susceptibility, χ(T), can be fitted to the Curie-Weiss expression, χ ∝(T-θ) , with θ=-13.4 K, indicative of significant antiferromagnetic coupling and 1 orders as an antiferromagnet at T =7.8 K.
Mn(O CMe)与 NaCN 或 LiCN 在水中反应生成一种浅绿色不溶性物质。对这种前所未有的、组成未知的复杂化合物的高分辨率同步辐射粉末衍射数据进行结构解析和 Rietveld 精修表明，它具有一种新的无碱有序结构基元，其中[Mn(μ-OH)]立方体和八面体[Mn(CN) ]离子通过 Mn-N≡C-Mn 键连接在三维空间中。该化合物的组成为{[Mn(OH)][Mn(OH)]}(μ-OH)[Mn(μ-CN)(CN)]⋅H O=[Mn(μ-OH)(OH)][Mn(μ-CN)(CN)]⋅H O，进一步简化为[Mn(OH)]Mn(CN) (1)。1 中有四个高自旋(S=5/2)Mn 位，它们在立方体内呈反铁磁耦合，并且与六个低自旋(S=1/2)八面体[Mn(CN) ]离子呈反铁磁耦合。在 40 K 以上，磁化率 χ(T)可以用居里-外斯表达式 χ∝(T-θ)拟合，其中 θ=-13.4 K，表明存在显著的反铁磁耦合，1 在 T=7.8 K 时作为反铁磁体有序。
