Atomic Number Dependent "Structural Transitions" in Ordered Lanthanide Monolayers: Role of the Hydration Shell

作者:Miller Mitchell; Chu Miaoqi; Lin Binhua; Bu Wei; Dutta Pulak*
来源:Langmuir, 2017, 33(6): 1412-1418.
DOI:10.1021/acs.langmuir.6b04609

摘要

When lanthanide ions are present in the aqueous subphase of a floating monolayer (Langmuir film), the ions attracted to the interface will in many cases form commensurate and/or incommensurate two-dimensional structures. These lattices depend not only on the molecules forming the monolayer, but also on the atomic number of the lanthanide, with a sudden change between the lattice formed by lighter ions and that formed by heavier ions under a given monolayer. Since there are few other relevant differences between the lanthanides, we attribute the Z-dependent "transition" to the number of water molecules associated with each ion. The first hydration shell is thought to vary continuously from in lighter lanthanides to in heavier lanthanides.