Microwave-assisted Preparation, Structures, and Photoluminescent Properties of [Ln(NO3)(2)(H2O)(3)(L)(2)](NO3)(H2O) {Ln = Tb, Eu; L=2-(4-pyridylium)ethanesulfonate, (4-pyH)(+)-CH2CH2-SO3-}

Abstract

Two lanthanide complexes, [Ln(NO3)(2)(H2O)(3)(L)(2)](NO3)(H2O) (Ln = Eu (1), Tb (2); L = 2-(4-pyridylium)ethanesulfonate, (4-pyH(+))-CH2CH2-SO3)}, were prepared from lanthanide nitrate and 4-pyridineethanesulfonic acid in H2O under microwave-heating conditions. Complexes 1 and 2 are isostructural, and the lanthanide metal in both complexes is coordinated to nine oxygen atoms. The pyridyl nitrogen in the ligand is protonated to give a zwitter ion that possesses an NH+ (pyridyl) positive end and an SO3- negative end. All O-H and N-H hydrogen atoms participate in hydrogen bonds to generate a two-dimensional (complex 1) or a three-dimensional network (complex 2). Complex 1 exhibits an intense red emission, whereas complex 2 exhibits an intense green emission in the solid state at room temperature.