A luminescent terbium coordination polymer for sensing methanol

Abstract

Two isostructural one-dimensional lanthanide coordination polymers, with the general formula {[Ln(aip)(H₂O)₅]·0.5(bdc)·3H₂O}_n [Ln = Eu (1), Tb (2); H₂aip = 5-aminoisophthalic acid, H₂bdc = 1,4-benzenedicarboxylic acid], have been synthesized by a diffusion technique at room temperature. Their structures were identified by X-ray diffraction. Complex 2 exhibits green emission, corresponding to the ⁵D₄ → ⁷F_J (J = 6–3) transitions of the Tb³⁺ ion. Significantly, when 2 was immersed in different organic solvents, it had a unique response to methanol compared to other solvents. Furthermore, 2 displayed highly sensitive and selective luminescence quenching to methanol with the ignorable interference of other small-molecule organics. This makes it a potential luminescence sensor for actual application in recognizing methanol.