Three coordination polymers based on 9,10-di(pyridine-4-yl)anthracene ligand: Syntheses, structures and fluorescent properties

Toggling the Oxygen Affinity between Anthracenes and Naphthalenes

We present the design of an anthracenyl-naphthyl (ANT-NAPH) dyad and its application as a luminescent 4-stage photo switch. Both segments can individually react with singlet oxygen to switch off an optical response. In their initial form the larger ANT component reacts significantly faster and thus an ANTO2-NAPH stage is turned on, observed by optical response of the remaining NAPH. To reduce its reactivity, ANT is substituted with two pyridine rings. This concept is first investigated and quantified on ANT and NAPH as separated molecules. Upon protonation the reaction of ANT becomes significantly slower. For the three possible pyridyl isomers this effect increases along the order meta Collapse

Key Words

• Anthracene
• Endoperoxide
• Naphthalene
• Singlet Oxygen
• Switching

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MESH Headings Collapse

Grants

• Universität Potsdam

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Affiliation(s)

Werner Fudickar Department of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476, Potsdam, Germany
Torsten Linker Department of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476, Potsdam, Germany

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Collaborators Collapse

Cooperative and Orthogonal Switching in the Solid State Enabled by Metal-Organic Framework Confinement Leading to a Thermo-Photochromic Platform

Cooperative behavior and orthogonal responses of two classes of coordinatively integrated photochromic molecules towards distinct external stimuli were demonstrated on the first example of a photo-thermo-responsive hierarchical platform. Synergetic and orthogonal responses to temperature and excitation wavelength are achieved by confining the stimuli-responsive moieties within a metal-organic framework (MOF), leading to the preparation of a novel photo-thermo-responsive spiropyran-diarylethene based material. Synergistic behavior of two photoswitches enables the study of stimuli-responsive resonance energy transfer as well as control of the photoinduced charge transfer processes, milestones required to advance optoelectronics development. Spectroscopic studies in combination with theoretical modeling revealed a nonlinear effect on the material electronic structure arising from the coordinative integration of photoresponsive molecules with distinct photoisomerization mechanisms. Thus, the reported work covers multivariable facets of not only fundamental aspects of photoswitch cooperativity, but also provides a pathway to modulate photophysics and electronics of multidimensional functional materials exhibiting thermo-photochromism.

Trapping and Releasing of Oxygen in Liquid by Metal-Organic Framework with Light and Heat

Nanoporous materials can adsorb small molecules into their nanospaces. However, the trapping of light gas molecules dissolved in solvents suffers from low concentration and poor adsorption affinity. Here, the reversible trapping and releasing of dissolved oxygen are shown through integrating photosensitization and chemical capturing abilities into a metal-organic framework (MOF), MOMF-1. 9,10-Di(4-pyridyl)anthracene (dpa) ligands in MOMF-1 generates singlet oxygen from triplet oxygen under photoirradiation without additional photosensitizers, and successively reacts with it to produce anthracene endoperoxide, forming MOMF-2, which is proved crystallographically. The reverse reaction also proceeds quantitatively by heating MOMF-2. Moreover, MOMF-1 exhibits excellent water resistance, and completely removes oxygen of ppm order concentrations in water. The new material shown in this report allows controlling of the amount of dissolved oxygen, which can be applicable in various fields relating to numerous oxidation phenomena.

Anion-Induced Structural Diversity of Zn and Cd Coordination Polymers Based on Bis-9,10-(pyridine-4-yl)-anthracene, Their Luminescent Properties, and Highly Efficient Sensing of Nitro Derivatives and Herbicides

Luminescent coordination polymers (CPs) of Zn²⁺ or Cd²⁺ and bis-9,10-(pyridine-4-yl)-anthracene (BA) show different 1D and 2D topologies depending on the anion used in the precursor. Compounds {[Zn(μ₂-BA)(MeOH)₂(p-Tos)₂]} _n (1) and {[Zn(μ₂-BA)(MeOH)₂(CF₃CO₂)₂]} _n (2) form linear structures and {BA@[Zn(μ₂-BA)(MeOH)₂(H₂O)₂](CF₃SO₃)₂} _n (3) featuring intercalation of uncoordinated BA molecules into linear ribbons. Cd-based CPs {[Cd(μ₂-BA)₂(ClO₄)₂]· n(DCM)} _n (4) and {[Cd(μ₂-BA)(MeOH)₂(Dioxane)(η₂-SiF₆)]·mDioxane} _n (5) form porous structures with 2D lattices. All complexes exhibit strong blue emission in the solid state with average lifetimes between 8 and 13 ns. The emission of compound 4 is sensitive to the presence of nitro aromatics, simazine, and trichloroanisole (TCA) and demonstrates nonlinear Stern-Volmer quenching kinetics. Limits of detection (LOD) of 15 and 16 ppb for picric acid and TCA were achieved, respectively.