wind-wheel-like pattern corresponding to an antiferrodistortive Jahn-Teller ordering. Thus, all MnFMn bridges are asymmetric: the bridge angles are between 136° and 141°. Magnetic investigations of Cs 2 NaMn 3 F 12 and Cs 2 KMn 3 F 12 indicate similar antiferromagnetic exchange interactions ( J k = −2.5 K ), but only for the Cs 2 K compound has 2D and 3D ordering been found at low temperatures. The results
摘要 对于一系列新的 Mn(III)
氟化物,其晶体结构已通过 X 射线单晶衍射确定:Cs 2 LiMn 3 F 12 ,空间群 R 3 ,Z = 3(多面体孪晶),a = 7.440( 1), c = 17.267(3) A , R = 1.95% ; 三个同构三斜相,空间群 P 1 ,Z = 2 。Cs 2 NaMn 3 F 12 , a = 7.305(1), b = 7.512(1), c = 10.376(2) A , α = 89.89(3)°, β = 87.32(3)°, γ = 89.89(3) )°, R = 2.75% ; Rb 2 NaMn 3 F 12 , a = 7.115(1), b = 7.482(1), c = 10.160(2) A , α = 89.92(3)°, β = 86.52(3)°, γ = 89.51(3) )°, R = 2.70% ; Rb