Lanthanide Contraction and Temperature-Dependent Structures of Lanthanide Coordination Polymers with Imidazole-4,5-Dicarboxylate and Oxalate

Three series of two-dimensional (2D) lanthanide coordination polymers oil Ln(1-11DC)(OX)0.5(H2O)(2)](n)center dot(H2O) (1Ln) (Ln = Pr and Nd), [Ln(H1DC)(OX)(0.5)(H2O)(n)center dot(H2O) (2Ln) (Ln = Eu and Tb), and [Ln(H1DC)(OX)(0.5)(H2O)](n) (3Ln) (Ln = Pr, Nd, Cu, and Tb) have been prepared by reacting Li-(NO3)(3)center dot 6H(2)O with imidazole-4,5-dicarboxylic acid (H3IDC) and oxalic acid (H2OX) at different temperatures under hydrothermal conditions. The results of structural analyses indicate that 1Ln and 2Ln are supramolecular isomers, in which 1Ln displays a 2D monolayer structure of [Ln(H1DC)(OX)(0.5)(H2O)(2)](n) with it (4.5(2))(4.5(3).7(2)) topology network, while 2Ln shows a different 2D monolayer structure containing alternating one-dimensional (1D) left-handed and right-handed helical chains of [Ln(H1DC)](infinity) bridged by OX2-. 3Ln has a 2D double-layer structure consisting of oxalate pillared [Ln(H1DC)(H2O)](n)(n+) layers. The effect of lanthanide contraction :old of temperature on the structures of 1Ln-3Ln was investigated. The structure related luminescent properties of 2Eu and 3Eu as well as 2Tb and 3Tb. were also examined.