- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Template-driven dense packing of pentagonal molecules in monolayer films
摘要： The integration of molecules with irregular shape into a long-range, dense and periodic lattice represents a unique challenge for the fabrication of engineered molecular scale architectures. The tiling of pentagonal molecules on a 2D plane can be used as a proof-of-principle investigation to overcome this problem since basic geometry dictates that a two-dimensional (2D) surface cannot be filled with a periodic arrangement of pentagons, a fundamental limitation that suggests that pentagonal molecules may not be suitable as building blocks for dense films. However, here we show that the 2D covalent organic framework (COF) known as COF-1 can direct the growth of pentagonal guest molecules as dense crystalline films at the solution/solid interface. We find that the pentagonal molecule corannulene adsorbs at two different sites on the COF-1 lattice, and that multiple molecules can adsorb into well-defined clusters patterned by the COF. Two types of these dense periodic packing motifs lead to a five-fold symmetry reduction compatible with translational symmetry, one of which gives an unprecedented high molecular density of 2.12 molecules/nm2.
关键词： host-guest system,fivefold symmetry,scanning probe microscopy,pentagonal molecules
更新于2025-09-23 15:21:21
-
Circularly Polarized Rooma??Temperature Phosphorescence and Encapsulation Engineering for MOFa??Based Fluorescent/Phosphorescent WLEDs
摘要： Optical materials with circularly polarized luminescence and room temperature phosphorescence currently attract great attention owing to their unique optoelectronic properties. Herein, via the coordination-induced assembly strategy, a homochiral metal–organic framework (MOF) 1 with high stability and porosity is successfully synthesized by using the achiral triphenylamine-based molecule as the building block. Remarkably, MOF 1 shows circularly polarized luminescence and phosphorescence at room temperature simultaneously, also with excellent anisotropic optical properties. Furthermore, MOF 1 can serve as a nanocontainer to construct dye-encapsulated host–guest systems. Importantly, the multicolor emissions including white-light emission can be achieved. The corresponding color rendering index and correlated color temperature values of light emitting device are 73 and 5541 K, when using dye-loaded MOF 1?RhB 10 (CIE: 0.33, 0.33) as single-phase white light-emitting phosphor. This study first reports circularly polarized phosphorescence based on MOF without precious metals under ambient conditions, and also is first time for phosphorescent polarized materials with high porosity. These results will open up a new pathway to the design of porous chiroptical materials and white-light materials.
关键词： circularly polarized luminescence,host–guest system,room temperature phosphorescence,white light emitting devices,metal–organic frameworks
更新于2025-09-23 15:21:01
-
Light-controlled switchable complexation by a non-photoresponsive hydrogen-bonded amide macrocycle
摘要： A new photoswitchable host-guest system based on a non-photoresponsive hydrogen-bonded (H-bonded) amide macrocycle and pyridinium salts was developed. The host is found to be capable of forming stable complexes with the analyzed protonated pyridine derivatives. Particularly, the guest capture and release process could be reversibly controlled to a greater extent via proton transfer by light stimulus with merocyanine 1-MEH. The present study offers a rare example of photo-responsive 2D shape-persistent H-bonded macrocyclic host-guest system, which may find applications in constructing interlocked molecular architecture.
关键词： proton transfer,pyridinium salts,photoswitchable,light stimulus,host-guest system,hydrogen-bonded amide macrocycle
更新于2025-09-19 17:13:59
-
Photophysics and electroluminescence of red quantum dots diluted in a thermally activated delayed fluorescence host
摘要： A feasible, universal, and low-cost strategy for quantum dot light-emitting devices (QLEDs) was provided to significantly enhance the electroluminescent performances. The emissive layer consists of organic host materials and quantum dots (QDs), and then the efficient energy transfer process remarkably promotes the device performances. It is confirmed that a highly efficient QLED can be realized by a host–guest system without common hole transport layers. The red device based on the thermally activated delayed fluorescence host and QD guest achieved a peak external quantum efficiency of 7.4%. Further, by simply modifying PEDOT:PSS with poly(4-styrenesulfonic acid), the work-function can be easily elevated, accompanied with the boosted external quantum efficiency to 11.9%. It is believed that such performances originate simultaneously from reduced interfacial fluorescence quenching, elevated work-function and efficient F?rster resonance energy transfer in the host–guest system.
关键词： external quantum efficiency,electroluminescent performances,quantum dot light-emitting devices,QLEDs,thermally activated delayed fluorescence,F?rster resonance energy transfer,host–guest system
更新于2025-09-16 10:30:52
-
Reversible Optical Writing and Data Storage in an Anthracene‐Loaded Metal‐Organic Framework
摘要： Metal-organic frameworks (MOFs) enable the design of host-guest systems with specific properties. In this work, we show how confinement of anthracene in a well-chosen MOF host leads to reversible yellow-to-purple photoswitching of fluorescence emission. This behavior has not been observed before for anthracene, either in pure form or adsorbed in other porous hosts. The photoresponse of the host-guest system is caused by the photodimerization of anthracene, which is greatly facilitated by the pore geometry, connectivity and volume as well as the structural flexibility of the MOF host. The photoswitching behavior is used to fabricate photopatternable and erasable surfaces that, in combination with data encryption and decryption, hold promise in product authentication and secure communication applications.
关键词： product authentication,photoswitching,anthracene,metal-organic frameworks,host-guest system
更新于2025-09-04 15:30:14
-
Reversible Optical Writing and Data Storage in an Anthracene-Loaded Metal-Organic Framework
摘要： Metal-organic frameworks (MOFs) enable the design of host-guest systems with specific properties. In this work, we show how confinement of anthracene in a well-chosen MOF host leads to reversible yellow-to-purple photoswitching of fluorescence emission. This behavior has not been observed before for anthracene, either in pure form or adsorbed in other porous hosts. The photoresponse of the host-guest system is caused by the photodimerization of anthracene, which is greatly facilitated by the pore geometry, connectivity and volume as well as the structural flexibility of the MOF host. The photoswitching behavior is used to fabricate photopatternable and erasable surfaces that, in combination with data encryption and decryption, hold promise in product authentication and secure communication applications.
关键词： product authentication,photoswitching,anthracene,metal-organic frameworks,host-guest system
更新于2025-09-04 15:30:14