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]

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 View the MathML sourceP3¯ 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 P 213 in the presence of a bulkier carboxylic acid, cyclohexanecarboxylic acid. In both [Eu(NTf2)3(H2O)3] crystals, View the MathML sourceNTf2- 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 P 21/n , in which View the MathML sourceNTf2- ligands coordinated to the Yb atom with only one oxygen atom.