Two‐Dimensional Metal‐Organic Layers as a Bright and Processable Phosphor for Fast White‐Light Communication

Abstract

A metal-organic layer (MOL) is a new type of 2D material that is derived from metal-organic frameworks (MOFs) by reducing one dimension to a single layer or a few layers. Tetraphenylethylene-based tetracarboxylate ligands (TCBPE), with aggregation-induced emission properties, were assembled into the first luminescent MOL by linking with Zr O (OH) (H O) (HCO ) clusters. The emissive MOL can replace the lanthanide phosphors in white light emitting diodes (WLEDs) with remarkable processability, color rendering, and brightness. Importantly, the MOL-WLED exhibited a physical switching speed three times that of commercial WLEDs, which is crucial for visible-light communication (VLC), an alternative wireless communication technology to Wi-Fi and Bluetooth, by using room lighting to carry transmitted signals. The short fluorescence lifetime (2.6 ns) together with high quantum yield (50 %) of the MOL affords fast switching of the assembled WLEDs for efficient information encoding and transmission.

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].…”

Recent Innovation of Metal-Organic Frameworks for Carbon Dioxide Photocatalytic Reduction

“…To maximize the photocatalytic conversion ability of Zr-based MOF 2D metal-organic layers (MOLs), crystalline is a perfect ally for the enhancement of light-harvesting capability of a MOF template. Characteristics like separated ligand by metal connected nodes, weak chromophore coupling region, and efficient energy transfer to reaction site attribute for 2D MOLs, mirroring the natural photocatalytic reaction approach of green plants [182,183]. Using this material in combination with Zr-based MOFs for photocatalytic CO2 conversion would result in better energy collection and utilization, thereby boosting photocatalytic conversion.…”

Metal–organic framework nanosheets (MONs): a new dimension in materials chemistry

“…Zhao and coworkers produced analogous layered structures based on BTB with both Hf and Zr M 6 O 4 (OH) 4 clusters synthesised using a modulated hydrothermal approach, 57 and Wang et al recently demonstrated a continuous ow reaction in order to synthesise the Zr analogue. 58 The same Zr 6 cluster but with different sites capped was used to create MONs with tetraphenylethylenebased tetracarboxylate (TCBPE), 23 as well as TCPP ligands. 59 A Hf 12 cluster was used by Cliffe et al who used 4,4-biphenyldicarboxylate (bpdc 2À ) to form a 3D framework containing a "double cluster" (Hf 12 O 8 (OH) 14 ) which they were able to exfoliate through selective scission of the interlayer ligands ( Fig.…”

“…93 Lin and coworkers found that the 12-connectivity of Zr 6 and Hf 6 SBUs could be modied by incorporating six formate ions into the SBU to produce nanosheets with thickness of <4 nm and lateral dimensions >10 mm, with nanosheets observed down to monolayer thickness. 23,29,50,61 Wang and coworkers demonstrated a "pseudoassembly disassembly" strategy for the formation of Zr 6 -(NiTCPP) MONs in high yield (85%) and high dimensional uniformity of around 200 Â 1.5 nm. 59 Incorporation of controlled concentrations of small monoacid (formic, acetic, lauric and oleic acid) ligands as a modulator into the reaction mixture lead to layered MOFs, within which the monoacids occupied the interlayer coordination sites of the Zr cluster (conrmed by quantitative NMR and SAXRD) which lead to destabilisation and "disassembly" to MONs.…”

“…20 Two-dimensional metal-organic framework nanosheets (MONs) have emerged as the most recent form-factor for metalorganic materials. MONs have been variously described in the literature as metal-organic framework nanosheets, 21 twodimensional MOFs, 22 metal-organic layers (MOLs), 23 metalorganic graphene analogues (MOGs), 24 metal-organic surfaces, 25 single-layered MOF based materials (MOFenes), 26 metal-organic akes, 27 two-dimensional coordination polymers, 28 coordination nanosheets (CONASH), 29 organometallic sheets, 30,31 and hybrid organic-inorganic nanosheets. 32 Whilst there are meaningful distinctions between some of the terms used in these descriptions, in an effort to draw out the commonality in the underlying chemistry, approaches to synthesis, techniques for characterisation and applications envisaged we group them here under a common name.…”