Photo‐controllable persistent luminescence at the single crystal level can be achieved by the integration of long‐lived room temperature phosphorescence (RTP) and photochromism within metal–organic ...frameworks (MOFs) for the first time. Moreover, the multiblock core–shell heterojunctions have been prepared utilizing the isostructural MOFs through an epitaxial growth process, in which the shell exhibits bright yellow afterglow emission that gradually disappears upon further irradiation, but the core does not show such property. Benefitting from combined persistent luminescence and photochromic behavior, a multiple encryption demo can be facilely designed based on the dynamic manipulating RTP via reversible photochromism. This work not only develops new types of dynamically photo‐controllable afterglow switch, but also provides a method to obtain MOFs‐based optical heterojunctions towards potential space/time‐resolved information encryption and anti‐counterfeiting applications.
Multiblock core–shell MOFs heterojunctions were prepared through an epitaxial growth process, in which the shell exhibits both persistent luminescence and photochromic properties. The bright yellow afterglow in MOFs shell can be detected before irradiation but almost disappears after coloration upon continuous UV irradiation.
The optical anti‐counterfeiting science and technology are currently restricted by the limited information loading capacity, and thus development of multi‐level and high‐security systems is urgently ...needed but still challenging. Herein, anti‐counterfeiting design strategies (including ASCII/5D codes and dynamic information storage) are reported by incorporation of abundant multi‐central luminescence and time‐resolved, excitation‐dependent ultralong phosphorescence. Self‐assembly of new single‐component 0D organic–inorganic metal halides (OIMHs) are facilely achieved, which exhibit divisible ultralong all‐phosphorescence, thermally activated delayed fluorescence, and single‐molecule white‐light emission, as proved by experiments and theoretical calculations. Interestingly, combing advantages of both inorganic cluster and π‐conjugation in OIMHs, the time‐dependent afterglow affords color‐variable emission in a wide wavelength range larger than 100 nm, providing extra color‐time dimensions for information encryption compared to traditional single‐color fluorescent anti‐counterfeiting. Moreover, white light‐emitting diode device is further developed to show high lighting ability for the single‐component OIMH. Therefore, this study paves an effective way to fabricate cluster‐based single‐component hybrids by equipping different emitters to confer diverse photoluminescence manners and satisfy down‐to‐earth application requirements.
This study provides a new strategy to the design of high‐performance molecular afterglow by merging clusteroluminogens and tunable π‐conjugated structures into the single‐component 0D organic–inorganic metal halides (OIMHs). The OIMHs serve as advanced single‐molecule white‐light emission and information security materials for high‐efficiency white‐light‐emitting diode dynamic information storage and high‐level anti‐counterfeiting applications.
Uncovering differences between crystalline and amorphous states in molecular solids would both promote the understanding of their structure–property relationships, as well as inform development of ...multi‐functional materials based on the same compound. Herein, for the first time, we report an approach to leverage crystalline and amorphous states of a zero‐dimensional metal‐organic complex, which exhibited negative and positive photochromism, due to the competitive chemical routes between photocycloaddition and photogenerated radicals. Furthermore, different polymorphs lead to the on/off toggling of photo‐burst movement (photosalient effect), indicating the controllable light‐mechanical conversion. Three demos were further constructed to support their application in information encryption and anti‐counterfeiting. This work provides the proof‐of‐concept of a state‐ and polymorph‐dependent photochemical route, paving an effective way for the design of new dynamically responsive systems.
An approach to leverage crystalline and amorphous states of a zero‐dimensional metal‐organic complex in order to tune negative and positive photochromism was proposed, which could be assigned to the competitive chemical routes between photocycloaddition and photogenerated radicals. Furthermore, both polymorphs exhibit mechanochromic photoemission, and lead to the on/off toggling of the light‐driven motion of bulky molecular crystals.
Exploitation of room temperature (RT) photochromism and photomagnetism to induce single-molecule magnet (SMM) behavior has potential applications toward optical switches and magnetic memories, and ...remains a tremendous challenge in the development of new bulk magnets. Herein, a series of chain complexes Ln3(H–HEDP)3(H2–HEDP)3·2H3–TPT·H4–HEDP·10H2O (QDU-1; Ln = Dy (QDU-1(Dy)), Gd (QDU-1(Gd)), and Y (QDU-1(Y)); HEDP = hydroxyethylidene diphosphonate; TPT = 2,4,6-tri(4-pyridyl)-1,3,5-triazine) were synthesized by solvothermal reactions. All the compounds exhibited reversible photochromic and photomagnetic behaviors via UV light irradiation at RT, induced by the photogenerated radicals via a photoinduced electron transfer (PET) mechanism. More importantly, the PET process induced significant variations in magnetic interactions for the Dy(III) congener. Strong ferromagnetic coupling with remarkably slow magnetic relaxation without applied dc fields was observed between DyIII ions and photogenerated O• radicals, showing SMM behavior after RT illumination. For the first time, we observed the reversible RT photochromism and photomagnetism in the lanthanide-based materials. This work realized the radicals-actuated on/off SMM behavior via RT light irradiation, providing a new strategy for constructing the light-induced SMMs.
Persistent luminescence has attracted great attention due to the unique applications in molecular imaging, photodynamic therapy, and information storage, among many others. However, tuning the ...dynamic persistent luminescence through molecular design and materials engineering remains a challenge. In this work, the first example of excitation‐dependent persistent luminescence in a reverse mode for smart optical materials through tailoring the excited‐state proton transfer process of metal cytosine halide hybrids is reported. This approach enables ultralong phosphorescence and thermally activated delayed fluorescence emission colors highly tuned by modulation of excitation wavelength, time evolution, and temperature, which realize multi‐mode dynamic color adjustment from green to blue or cyan to yellow‐green. At the single crystal level, the 2D excitation/space/time‐resolved optical waveguides with triple color conversion have been constructed on the organic‐metal halide microsheets, which represent a new strategy for multi‐dimensional information encryption and optical logic gate applications.
Reversed excitation‐dependent persistent luminescence can be obtained in metal cytosine halides by controlling the process of excited‐state proton transfer (ESIPT). The metal cytosine halides further exhibit multi‐mode (excitation/space/time) triple‐color luminescent conversion, which have promising applications in multi‐dimensional information encryption and photonic logic gates.
Two novel photochromic and photomagnetic complexes actuated by nonphotochromic ligands have been hydrothermally synthesized through the pillar-layer strategy. After Xe lamp irradiation at room ...temperature, compound 1 shows naked-eye detectable photochromism, while 2 exhibits an efficient photodemagnetization effect.
Luminescent metal clusters have attracted great interest in current research; however, the design synthesis of Al clusters with color‐tunable luminescence remains challenging. Herein, an ...Al8(OH)8(NA)16 (Al8, HNA = nicotinic acid) molecular cluster with dual luminescence properties of fluorescence and room‐temperature phosphorescence (RTP) is synthesized by choosing HNA ligand as phosphor. Its prompt photoluminescence (PL) spectrum exhibits approximately white light emission at room temperature. Considering that halogen atoms can be used to regulate the RTP property by balancing the singlet and triplet excitons, different CdX2 (X− = Cl−, Br−, I−) are introduced into the reactive system of the Al8 cluster, and three new Al8 cluster‐based metal‐organic frameworks, {Al8Cd3Cl5(OH)8(NA)17H2O·2HNA}n (CdCl2‐Al8), {Al8Cd4Br7(OH)8(NA)16CH3CN·NA·HNA}n (CdBr2‐Al8) and {Al8Cd8I16(OH)8(NA)16}n (CdI2‐Al8) are successfully obtained. They realize the color tunability from blue to yellow at room temperature. The origination of fluorescence and phosphorescence has also been illustrated by structure‐property analysis and theoretical calculation. This work provides new insights into the design of multicolor luminescent metal cluster‐based materials and develops advanced photo‐functional materials for multicolor display, anti‐counterfeiting, and encryption applications.
By fixing a phosphor of nicotinic acid into crystalline state, an Al8 cluster with dual luminescent properties of fluorescence and room‐temperature phosphorescence (RTP) is obtained. Introducing CdX2 into the reactive system of the Al8 cluster to regulate RTP by balancing the singlet and triplet excitons, three heterometallic Al8‐based metal‐organic frameworks are obtained. They realize the luminescent color tunability from blue to yellow.
A 3D zinc-organic hybrid Zn
3
(D-Cam)
3
(tib)
2
·2H
2
O (1) exhibits triple-mode dependent (including excitation wavelength, time and temperature) long-persistent luminescence. Experimental and ...theoretical calculations support that the long lifetime and color-tunable afterglow may be due to the dispersive electronic state distribution. Furthermore, the hybrid is also used for optical anti-counterfeiting and information encryption applications.
A 3D metal-organic hybrid Zn
3
(D-Cam)
3
(tib)
2
·2H
2
O exhibits triple-mode (excitation wavelength-, time- and temperature-) dependent persistent luminescence properties.
A reversible CO2-responsive luminescent material was constructed by a facile hydrogen-bond self-assembly of a two-component ionic crystal. The modification of CO2 on the ionic crystal not only ...alternates the green afterglow, but also endows the material with inverse excitation wavelength dependence for multicolor emission.
Over the past decade, significant progress has been made in the direct C-H acylation of naphthalenes, occurring at the α or β-positions to yield valuable ketones through Friedel-Crafts acylation or ...transition-metal-catalysed carbonylative coupling reactions. Nevertheless, highly regioselective acylation of naphthalenes remains a formidable challenge. Herein, we developed a nickel-catalysed reductive ring-opening reaction of 7-oxabenzonorbornadienes with acyl chlorides as the electrophilic coupling partner, providing a new method for the exclusive preparation of β-acyl naphthalenes.
A nickel-catalysed reductive ring-opening reaction of 7-oxabenzonorbornadienes with acyl chlorides as the electrophilic coupling partner was developed, generating β-acyl naphthalene as the unique product without any α iso.
