Metal-Halide Coordination Polymers with Excitation Wavelength- and Time-Dependent Ultralong Room-Temperature Phosphorescence

Metal–organic hybrids with ultralong room-temperature phosphorescence (RTP) have potential applications in many fields, including optical communications, anticounterfeiting, encryption, bioimaging, and so on. Herein, we report two isostructural one-dimensional zinc-organic halides as coordination polymers ZnX2(bpp) (X = Cl, 1; Br, 2; bpp = 1,3-di(4-pyridyl)propane) with excitation wavelength- and time-dependent ultralong RTP properties. The dynamic multicolor afterglow can be assigned to the emission of the pristine ligand bpp and its interactions with halogen atoms. Experiments and theoretical calculations both suggest that ZnX2 is crucial for ultralong RTP: (a) the metal coordination and X...π bonds in coordination polymers fix the bpp molecules and suppress the nonradiative transitions; (b) the spin-orbital coupling of coordination polymers is largely enhanced relative to the bpp because of the heavy atom effect; and (c) the charge transfer exists between halogens and bpp ligand. Therefore, this work not only presents metal-halide coordination polymers with excitation wavelength- and time-dependent RTP properties, but also provides a facile method for the new types of dynamic multicolor afterglow materials

Two Cobalt-diphosphonates Templated by Long-Chain Flexible Amines: Synthesis, Structures, Proton Conductivity, and Magnetic Properties

Two new cobalt-diphosphonates templated by protonated 1,2-bis­(3-aminopropylamino)­ethane (BAPEN), (C₈N₄H₂₆)_0.5·[Co­(HEDP)]·H₂O (<b>1</b>) and (C₈N₄H₂₆)·[Co₂(HEDP)₂(H₂O)₂]·5H₂O (<b>2</b>), were hydrothermally prepared (HEDP = CH₃C­(OH)­(PO₃)₂, 1-hydroxyethylidenediphosphonate). Compounds <b>1</b> and <b>2</b> exhibit anionic 1D Co-HEDP chain and 2D Co-HEDP layer structure, respectively. The structure diversities from 1D chain to 2D layer was realized by adjusting the synthetic parameters. Their magnetism and proton conduction have been studied. Magnetic measurements indicated that the title compounds exhibit weak magnetic interactions. Compounds <b>1</b> and <b>2</b> feature a proton conductivity of 3.57 × 10^–4 and 9.43 × 10^–5 S cm^–1 at 100% relative humidity and 65 °C, respectively