Auxiliary ligand-assisted two novel one-dimensional indium coordination polymers: Synthesis, crystal structures and photoluminescence characterization effected by solvent and temperature

•In1 and In2 have 3D structure constructed through C–H⋯Cl or π⋯π interaction.•In1 and In2 both display stable blue fluorescent in the solid state.•In1 possesses solvent-dependent photoluminescence.•In2 has good fluorescence stability in different solvents.•In1 and In2 are stable up to 450 and 495 °C, respectively.

Two new indium coordination polymers (CPs) with mixed-ligand formulated as {[In(1,4-bda)1.5(phen)]·2H2O}n (In1) and {In(1,4-bda)(2,2′-bipy)Cl}n (In2) (1,4-H2bda = 1,4-benzenedicarboxylic acid; phen = 1,10-phenanthrolin; 2,2′-bipy = 2,2′-bipyridine) have been synthesized and characterized by single-crystal X-ray diffraction, infrared (IR), elemental analysis and thermal gravimetric analyses (TGA). In1 exhibits one-dimensional (1D) ladder chain, which further forms three-dimensional (3D) structure with π⋯π stacking interaction. Formation of 3D compact supramolecular framework in In2 is generated through C–H…Cl hydrogen bonding contacts and π⋯π stacking interaction. The photoluminescence (PL) characterizations to In1 and In2 affected by solvent and temperature are studied in detail. Thermogravimetric curves showed that In1 and In2 start to undergo phase transition until ca. 450 °C and 495 °C, respectively.

Graphical abstractTwo new indium coordination polymers (CPs) with mixed-ligand formulated as {[In(1,4-bda)1.5(phen)]·2H2O}n (In1) and {In(1,4-bda)(2,2′-bipy)Cl}n (In2) (1,4-H2bda = 1,4-benzenedicarboxylic acid; phen = 1,10-phenanthrolin; 2,2′-bipy = 2,2′-bipyridine) have been synthesized under hydrothermal conditions. In1 exhibits one-dimensional (1D) ladder chain, which further forms three-dimensional (3D) structure by π⋯π stacking interaction. The 3D inserted compact supramolecular framework in In2 is generated through C–H⋯Cl hydrogen bonding contacts and π⋯π stacking interaction between neighboring 1D zigzag chains. The emission peak positions of In1 are sensitive to different polar solvents, assuming solvent-dependent PL. By contrast, the PL spectrum of In2 does not change in different solvents, and possesses better PL stability.Figure optionsDownload full-size imageDownload as PowerPoint slide