A new series of 2D lanthanide 5-hydroxyisophthalate coordination polymers

A new series of isostructural 2D layer coordination polymers {[Ln(hisp)(Hhisp)(H2O)2]·2H2O}n (Ln = La(1), Tb(2), Er(3), H2hisp = 5-hydroxyisophthalic acid) have been synthesized by hydrothermal reactions of lanthanide chloride with 5-hydroxyisophthalic acid under a mild-acid condition (pH 4–5). The 2D layer coordination polymers, which comprise 1D Ln–O–C–O–Ln chains cross-linked by the phenylene moieties of the ligand, are further extended into three-dimensional supramolecular networks by the hydrogen bonding interactions and π–π aromatic stacking interaction. The thermal stability and photoluminescent properties of compound 2 have also been investigated.