Isostructural series of [{Al(H2O)6}{Ln(pda)3}]•10H2O: Synthesis, structure and photoluminescence

A new series of six isostructural molecular solids of the composition [{Al(H2O)(6)}{HLn(pda)(3)}]center dot 10H(2)O where Ln = Sm, Eu, Gd, Tb, Dy and Yb have been synthesized and structurally characterised. All the solids are built of three major building blocks: the lanthanide dipicolinate anion, {Ln(pda)(3)}(3-), the counter cation, {Al(H2O)(6)}(3+) and a hexameric water cluster in chair form. The cations and the anions supramolecularly aggregate forming a 2D H-bonded sheet; the sheets are further stabilised through hexameric water clusters in chair form and water molecules. The crystals containing Sm, Eu, Tb and Dy showed characteristic emission of lanthanide ions.