Two Cu-based cluster coordination polymers constructed from two thioether tripod tricarboxylic acid ligands: Synthesis, crystal structure and fluorescence sensing

摘要

Two new symmetrical tripod thioether tricarboxylic acid ligands, 1,3,5-tris(4-carboxyphenylsulfanylmethyl) benzene and 1,3,5-tris(4-carboxyphenylsulfanylmethyl)-2,4,6-trimethylbenzene (H3L and CH3-H3L) have been designed and synthesized. The reaction of two ligands with Cu2+ ions afforded two Cu-based cluster coordination polymers (CPs), [Cu3L](n) (1) and {[Cu(CH3-HL)DMF]center dot DMF}(n) (2). It was interesting to note that the substituent groups on central phenyl rings in ligands caused the bend tripodal and planar geometries as well as different coordinated modes for H3L and CH3-H3L, respectively, leading to different structures of CPs 1 and 2. 1 with monovalent Cu+ ions shows a 3D layer-stacking framework with hexanuclear [Cu-6(CO2)(6)] clusters, while 2 with divalent Cu2+ ions forms a 1D chain with dinuclear [Cu-2(CO2)(4)] paddlewheel clusters. 1 shows strong orange fluorescence and exhibits fluorescence sensing for Cr2O42- and Fe3+ ions with good selectivity and sensitivity.