2-and 1-D coordination polymers of Dy(III) and Ho(III) with near infrared and visible luminescence by efficient charge-transfer antenna ligand

Abstract

Two new lanthanide-based coordination complexes, [Dy(2-stp).2(H2O)]n (1) and {[Ho(2-stp).3(H2O)]center dot(H2O)}(n) (2) [2-stp = 2-sulfoterephthalic acid] were synthesized by hydrothermal reaction and characterized by elemental analysis, UV, IR, single crystal X-ray diffraction and solid state photoluminescence. Dy-III and Ho-III atoms are eight-coordinated and adopt a distorted square-antiprismatic geometry in complexes 1 and 2, respectively. In compound 1, Dy atoms are coordinated by four bridging 2-stp ligands forming two-dimensional (2D) layer, while Ho atoms by three bridging 2-stp ligands creating one dimensional (1D) double chains in 2. In addition, complexes 1 and 2 display in the solid state and at room temperature an intense yellow emission, respectively; this photoluminescence is achieved by an indirect process (antenna effect). The excellent luminescent performances make these complexes very good candidates for potential luminescence materials. (C) 2017 Elsevier B.V. All rights reserved.