Crystal structures of [M(NTf2)(3)( H2O)(n)] (M = Eu and Yb) and a template effect of linear molecules on the 3D hydrogen bonding network structure of [Eu(NTf2)(3)(H2O)(3)]

摘要

Lewis acid catalysts [Eu(NTf2)(3)] and [Yb(NTf2)(3)] can be easily crystallized from a p-xylene solution in the presence of carboxylic acids and a small amount of water to give a trihydrate and a pentahydrate, respectively. In the crystallization of [Eu(NTf2)(3)(H2O)(3)], linear molecules such as n-alkanes and n-alkanoic acids act as templates to form crystals belonging to the trigonal space group P (3) over bar with a hexagonal cylindrical structure, which is constructed by 3D hydrogen bonding network. On the other hand, [Eu(NTf2)(3)(H2O)(3)] crystallized in the cubic space group P2(1)3 in the presence of a bulkier carboxylic acid, cyclohexanecarboxylic acid. In both [Eu(NTf2)(3)(H2O)(3)] crystals, NTf2- ligands act as bidentate ligands coordinating to the Eu atom through two oxygen atoms. [Yb(NTf2)(3)] crystallized as a pentahydrate in the monoclinic space group P2(1), in which NTf2- ligands coordinated to the Yb atom with only one oxygen atom. (c) 2006 Elsevier B.V. All rights reserved.