Temperature and solvent controlled syntheses of six hydrous 5-(3-pyridylmethoxy)isophthalate Cd(II) coordination polymers

Abstract

Six hydrous Cd(II) coordination polymers based on a scorpion-like 5-(3-pyridylmethoxy)isophthalic acid (H2L), namely {[CdL(H2O)]·2H2O}n (1), [Cd4L4(H2O)4]n (2), [CdL(H2O)]n (3), [CdL(H2O)2]n (4), {[CdL(H2O)]·H2O}n (5) and [CdL]n (6), were hydrothermally synthesized and characterized by EA, IR, PXRD, TG-DSC and X-ray structural analysis. Temperature and solvent play crucial roles in the preparation of the coordination polymers. Complexes 1–3 were prepared in a H2O-DMF (6:2) solvent system at slightly different temperature (85, 100 and 120°C). Complexes 4–6 were prepared in different H2O-DMF solvents (6:3 and 8:2) and H2O-MeCN (3:6) solvent. These complexes possess different coordinated and/or lattice water molecules, and exhibit structural diversity and various topology nets. Complex 1 is a 2D double-layered coordination polymer. Complex 2 features a 3D porous framework with irl topology. Complex 3 displays a 2D double-layered network. Complex 4 is a 3D coordination polymer with sra topology. Complex 5 exhibits a 3D wave-like framework with sra topology. Complex 6 is a 3D coordination polymer with self-catenated hxg-d topology. 5-(3-Pyridylmethoxy)isophthalate adopts three types of coordination modes. These complexes exhibit higher thermal stability and emit strong luminescence.