High-Performance Blue-Excitable Yellow Phosphor Obtained from an Activated Solvochromic Bismuth-Fluorophore Metal–Organic Framework

Abstract

We report the synthesis, structure, and photoluminescence properties of a new bismuth based luminescent metal−organic framework (LMOF). The framework is comprised of a 9-coordinated Bi 3+ building unit and 4′, 4‴, 4⁗′, 4⁗‴-(ethene-1,1,2,2-tetrayl)tetrakis([1,1′-biphenyl]-4carboxylic acid) (H 4 tcbpe) organic linker, which has strong yellow aggregation induced emission (AIE). The structure can be viewed as two interpenetrated 4,4-anionic nets that are stabilized by K + ions forming one-dimensional helical inorganic chains by connecting bismuth nodes through shared oxygen bonds. The as-made LMOF has a bluish emission centered at 459 nm with an internal quantum yield of 57% when excited at 360 nm. The emission properties of the LMOF were found to be highly solvochromic with respect to DMF. Upon partial solvent removal, the framework undergoes significant red-shifting to a greenish emission centered at 500 nm. Complete removal of DMF results in additional red-shifting fluorescence coupled with structural changes. The resulting material has strong blue-excitable (455 nm) yellow emission centered at 553 nm, with a quantum yield of 74%, which is maintained after heating in air for 5 days at 90 °C. This is the second highest quantum yield value for blue-excited yellow emission among all reported LMOFs.

α‐ and β‐[Bmim][BiCl4(2,2′‐bpy)]: Two Polymorphic Bismuth‐Containing Ionic Liquids with Crystallization‐Induced Phosphorescence

“…Accurate explanation of the luminescence mechanism is notoriously difficult, since diverse charge‐transfer (CT) processes or combinations thereof are possible. For instance, the luminescence of coordination polymers based on Bi 3+ and carboxylate ligands is mainly attributed to intra‐ligand transitions (ILCT) and/or ligand‐to‐metal charge‐transfer (LMCT) . In halobismuthates, however, metal‐centered sp excited states along with halogen‐to‐metal charge‐transfer (XMCT) have proved to be vitally important to their emissions .…”

Multi‐Photon Absorption in Metal–Organic Frameworks

“…[12] From our model, we deduce that the 2PAw ould be maximized in aM OF with ap lanar arrangement of the TCPE linker,a st hen the S ab would be the sum of all molecules.Agood representation of such an ideal arrangement is for example given by [Zn 2 (TCPE)],aM OF known for its high quantum efficiency. [9c] Them odel thus allows existing TCPE-based MOF structures to be quickly evaluated for their MPA performance.F or example,w ee stimate 2PAc ross-section values of 156 GM/chromophore for [Cd 3 (TCPE) 1.5 (H 2 O) 2 -(DMF)], [21] 165 GM/chromophore for K[Bi(TCPE)(DMF) 2 ] (DMF = N,N-dimethylformamide), [22] and 170 GM/chromophore for [Zn 2 (TCPE)]. [9c] Indeed, in full accordance with the model we measure avalue of 4300 GM for [Zn 2 (TCPE)],that is,avalue that even exceeds the one of our previously topperforming MOF 3 (Supporting Information, Figure S17 and Table S4).…”

Salts and Co-Crystalline Assemblies of Tetra(4-Pyridyl)Ethylene with Di-Carboxylic Acids

“…This general property of tetraarylethylenes coupled with a geometrically appealing molecular structure has resulted in studies examining the utility of tetraarylethylene derivatives in solution phase and solid state supramolecular assembly processes, often with the aim of capitalizing on enhanced luminescence to deliver new optical or sensing materials [19,20]. Indeed, several crystalline luminescent metal organic frameworks (MOFs) have been prepared using the symmetrical tetraphenylethylene carboxylic acid (2) as well as the extended biphenylethylene analogue (3) as rigid metal ligating components [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. Additionally, we have investigated the electrooptical properties of crystalline organic assemblies constructed from phenoxyacetic acid (4) and bis(pyridine) derivatives [36].…”