Du Yi, O'Hare Dermot
Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford, United Kingdom OX1 3TA.
Inorg Chem. 2008 Dec 15;47(24):11839-46. doi: 10.1021/ic801639e.
The anion-exchange reaction of the layered alpha-cobalt hydroxides Co(OH)(1.75)(DDS)(0.25).0.6H(2)O (1) and Co(OH)(1.7)Cl(0.3).0.4H(2)O (3) with carbonate has been investigated. For 3 the reaction proceeds by complete displacement of the interlayer Cl(-) anions by CO(3)(2-) to give Co(OH)(1.7)(CO(3))(0.15).0.6H(2)O (4). Remarkably for 1 we only observe ion-exchange of the DDS(-) from every other layer to give the second stage intercalate Co(OH)(1.75)(DDS)(0.07)(CO(3))(0.09).0.5H(2)O (2). The kinetics of these processes have been investigated using time-resolved in situ energy dispersive XRD and small/wide-angle X-ray scattering. In both cases the reaction order (n) was found to be consistent with a two-dimensional diffusion controlled model. Both 3 and 4 are magnetically ordered, and dc and ac magnetic susceptibility measurements have been used to explore their 3D ferrimagnetically ordered ground states.
研究了层状α-钴氢氧化物Co(OH)(1.75)(DDS)(0.25).0.6H₂O (1)和Co(OH)(1.7)Cl(0.3).0.4H₂O (3)与碳酸盐的阴离子交换反应。对于3，反应通过CO₃²⁻完全取代层间Cl⁻阴离子进行，生成Co(OH)(1.7)(CO₃)(0.15).0.6H₂O (4)。值得注意的是，对于1，我们仅观察到每隔一层的DDS⁻发生离子交换，生成第二阶段插层产物Co(OH)(1.75)(DDS)(0.07)(CO₃)(0.09).0.5H₂O (2)。利用时间分辨原位能量色散X射线衍射和小角/广角X射线散射研究了这些过程的动力学。在这两种情况下，发现反应级数(n)与二维扩散控制模型一致。3和4都呈现磁有序，并且已使用直流和交流磁化率测量来探究它们的三维亚铁磁有序基态。
