Department of Chemistry, Central College, Bangalore University, Bangalore 560 001, India.
J Colloid Interface Sci. 2010 Apr 15;344(2):508-12. doi: 10.1016/j.jcis.2010.01.013. Epub 2010 Jan 14.
The iodide-containing layered double hydroxides (LDHs) of Mg and Zn with Al crystallize by the inclusion of extensive positional disorder of I(-) ions in the interlayer region. I(-) ion given its poor charge to size ratio can neither screen effectively the positive charge nor participate in H-bonding with the metal hydroxide layers. Thereby the I(-) ions are not stabilized in sites close to the seat of positive charge of the metal hydroxide layers (6c), nor in sites that facilitate H-bonding (3b or 18h). On the other hand, OH(-) from water can do both and effectively displaces I(-) from the interlayer.
含碘的层状双氢氧化物(LDHs)的 Mg 和 Zn 与 Al 一起结晶,其中 I(-)离子在层间区域存在广泛的位置无序。由于 I(-)离子的电荷与尺寸比不佳,它既不能有效地屏蔽正电荷,也不能与金属氢氧化物层形成氢键。因此,I(-)离子不会稳定在靠近金属氢氧化物层正电荷中心的位置(6c),也不会稳定在有利于氢键形成的位置(3b 或 18h)。另一方面,来自水的 OH(-)可以同时做到这两点,并有效地将 I(-)从层间取代出来。