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Bio-templated luminescent noble metal nanoclusters (NCs) have attracted great attention for their intriguing physicochemical properties. Continuous efforts are being made to prepare NCs with high fluorescence quantum yield (QY), good biocompatibility, and tunable emission properties for their widespread practical applications as new-generation environment-friendly photoluminescent materials in materials chemistry and biological systems. Herein, we explored the unique photophysical properties of silver nanoclusters (AgNCs) templated by cytosine-rich customized hairpin DNA. Our results indicate that a 36-nucleotide containing hairpin DNA with 20 cytosine (C20) in the loop can encapsulate photostable red-emitting AgNCs with an absolute QY of ∼24%. The luminescent properties in these DNA-templated AgNCs were found to be linked to the coupling between the surface plasmon and the emitter. These AgNCs exhibited excellent thermal sensitivity and were employed to produce high-quality white light emission with an impressive color rendering index of 90 in the presence of dansyl chloride. In addition, the as-prepared luminescent AgNCs possessing excellent biocompatibility can effectively mark the nuclear region of HeLa cells and can be employed as a luminescent probe to monitor the cellular dynamics at a single molecular resolution. [ABSTRACT FROM AUTHOR]

Aggregation-induced emission (AIE) is an effective strategy for improving the photoluminescence (PL) performance of metal nanoclusters (MNCs). However, the origin of AIE in MNCs is still not fully understood, which is pivotal for the design of AIE luminogens (AIEgens). Here, water soluble silver nanoclusters (Ag NCs) with AIE properties were synthesized. These as-synthesized non-luminescent Ag NCs will become photoluminescent when transferred from water to ethanol, and the emission peak was redshifted from ∼560 to ∼600 nm and largely intensified with the addition of Cu2+. The addition of Cu2+ makes a big difference in the PL properties of Ag NCs. That is, the PL will be enhanced if Cu2+ is added with the sequence "Ag NCs + Cu2++EtOH." In contrast, the PL will be quenched if Cu2+ is added with the sequence "Ag NCs + EtOH + Cu2+." The PL was from the supramolecular clusters formed by the assembly of capping ligands on the confined surface of individual silver clusters through weak interactions. The addition of Cu2+ could regulate the assembly structure and further affect the energy lever (p-band) through space electron interactions. These results provide new insights into the AIE process in metal nanoclusters. [ABSTRACT FROM AUTHOR]

Understanding photoluminescent mechanisms has become essential for photocatalytic, biological, and electronic applications. Unfortunately, analyzing excited state potential energy surfaces (PESs) in large systems is computationally expensive, and hence limited with electronic structure methods such as time-dependent density functional theory (TDDFT). Inspired by the sTDDFT and sTDA methods, time-dependent density functional theory plus tight binding (TDDFT + TB) has been shown to reproduce linear response TDDFT results much faster than TDDFT, particularly in large nanoparticles. For photochemical processes, however, methods must go beyond the calculation of excitation energies. Herein, this work outlines an analytical approach to obtain the derivative of the vertical excitation energy in TDDFT + TB for more efficient excited state PES exploration. The gradient derivation is based on the Z vector method, which utilizes an auxiliary Lagrangian to characterize the excitation energy. The gradient is obtained when the derivatives of the Fock matrix, the coupling matrix, and the overlap matrix are all plugged into the auxiliary Lagrangian, and the Lagrange multipliers are solved. This article outlines the derivation of the analytical gradient, discusses the implementation in Amsterdam Modeling Suite, and provides proof of concept by analyzing the emission energy and optimized excited state geometry calculated by TDDFT and TDDFT + TB for small organic molecules and noble metal nanoclusters. [ABSTRACT FROM AUTHOR]

Light‐harvesting is of vital importance for many events, such as photosynthesis. To efficiently gather and transfer solar energy, delicate antenna is needed, which has been achieved by algae and plants. However, construction of efficient light‐harvesting systems using multiple, artificial building blocks is still challenging. Here, blue‐emitting organosilicone capsules containing carbon dots (denoted as CDs‐Si) in ethanol are prepared, which can effectively transfer energy to green‐emitting (silicone‐functionalized bodipy, Si‐BODIPY) or red‐emitting (rhodamine b, RhB) dyes. In ternary system, sequential Förster resonance energy transfer from CDs‐Si to Si‐BODIPY and further to RhB is realized, which is accompanied with a less pronounced, parallel FRET directly from CDs‐Si to RhB. The overall efficiency of energy transfer reaches ≈86%. By introducing a photoswitch (1,2‐bis(2,4‐dimethyl‐5‐phenyl‐3‐thienyl)‐3,3,4,4,5,5‐hexafluoro‐1‐cyclopentene, DAE) to the system, the emission becomes switchable under alternative illumination with UV and visible light, leading to the formation of smart artificial light‐harvesting systems. [ABSTRACT FROM AUTHOR]

Mono- and binuclear Cu(I) complexes were isolated employing 2,1,3-benzoselenadiazole (BSeD) as the N-donor ligand, and triphenylphosphine or bis[(2-diphenylphosphino)phenyl] ether (DPEphos) as P-donors. Then, 77Se NMR was measured for the free ligand and the corresponding Cu(I) derivatives, and the related signal was downshifted by 12.86 ppm in the case of [Cu(BSeD)(PPh3)2(ClO4)], and around 15 ppm for the binuclear species. The structure of [Cu(BSeD)(PPh3)2(ClO4)] and [Cu2(μ2-BSeD)(DPEphos)2(ClO4)2] was confirmed by single-crystal X-ray diffraction. The geometry of the Cu(I) complexes was optimized through DFT calculations, and the nature of the Cu···O interaction was investigated through AIM analysis. The three Cu(I) complexes were characterized by intense absorption under 400 nm and, after being excited with blue irradiation, [Cu(BSeD)(PPh3)2(ClO4)] and [Cu2(μ2-BSeD)(PPh3)4(ClO4)2] exhibited weak red emissions centered at 700 nm. The lifetimes comprised between 121 and 159 μs support the involvement of triplet excited states in the emission process. The photoluminescent properties of [Cu(BSeD)(PPh3)2(ClO4)] were supported by TDDFT computations, and the emission was predicted at 710 nm and ascribed to a metal-to-ligand charge transfer (3MLCT) process, in agreement with the experimental data. [ABSTRACT FROM AUTHOR]

Excited‐state intramolecular proton transfer (ESIPT) molecules, which feature large Stokes shifts to avoid self‐absorption, play an essential role in photoluminescent bioimaging probes. Herein, we report the development of an ESIPT molecule 3‐(3‐hydroxypyridin‐2‐yl)isoquinolin‐4‐ol (PiQ). PiQ not only undergoes a distinct ESIPT process unlike the symmetrical 2,2′‐bipyridyl‐3,3′‐diol but also exhibits aggregation‐induced emission (AIE) characteristics. PiQ self‐assembles into aggregates with an average size of 241.0±51.9 nm in aqueous solutions, leading to significantly enhanced photoluminescence. On the basis of the ESIPT and AIE characteristics of PiQ, the latter is functionalized with a hydrogen peroxide‐responsive 4‐pinacoratoborylbenzyl group (B) and a carboxylesterase‐responsive acetyl group (A) to produce a photoluminescent probe B−PiQ−A. The potential of PiQ for applications in bioimaging and chemical sensing is underscored by its efficient detection of both endogenous and exogenous hydrogen peroxide in living cells. [ABSTRACT FROM AUTHOR]

The tricarbonylrhenium complexes that incorporate a mesoionic carbene ligand represent an emerging and promising class of molecules, the solid-state optical properties of which have rarely been investigated. The aim of this comprehensive study is to compare three of these complexes with their 1,2,3-triazole-based analogues. The Hirshfeld surface analysis of the crystallographic data revealed that the triazolylidene derivatives are more prone to π–π interactions than their 1,2,3-triazole-based counterparts. The FT-IR and electrochemical data indicated a stronger electron donor effect from the organic ligand to the rhenium atom for triazolylidene derivatives, which was confirmed by DFT calculations. All compounds were phosphorescent in solution, where the 1,2,3-triazole-based complexes showed unusually strong dependence on dissolved oxygen. All compounds also emitted in the solid state, some of them exhibited marked solid-state luminescence enhancement (SLE) effect. The 1,2,3-triazole based complex Re-Phe even displayed astounding photoluminescence efficiency with quantum yield up to 0.69, and proved to be an excellent candidate for applications linked to aggregation-induced emission (AIE). Interestingly, one triazolylidene-based complex (Re-T-BOP) showed attractive antibacterial activity. This study highlights the potential of these new molecules for applications in the fields of photoluminescent and therapeutic materials, and provides the first bases for the design of efficient molecules in these research areas. [ABSTRACT FROM AUTHOR]

The pursuit of efficient materials for technological applications is essential. Among these materials, zirconia emerges as a promising candidate with potential for several applications, from applications related to mechanical resistance to optoelectronic applications. By introducing dopants into this compound, it becomes feasible to modulate its inherent properties. In this study, ZrO 2 doped with strontium was synthesized for the first time via the sonochemical method at different percentages in mol (1, 2, 4, and 8 mol%). Analysis via X-ray diffraction (XRD) and Raman spectroscopy unveiled the formation of both monoclinic and tetragonal phases, with the latter being stabilized through the incorporation of the dopant element. In addition to observing irregular morphology through scanning electron microscopy (SEM-FEG), a reduction in particle size was also evidenced following the introduction of Sr2+ ions, a phenomenon corroborated via Rietveld refinement. The reflectance spectra of the doped samples exhibited an optical absorption tail characterized by the Urbach energy (E U), indicating an increase in structural disorder in the samples. The photoluminescence (PL) results indicated that the introduction of Sr2+ ions into the ZrO 2 matrix induced modifications in the characteristics of the spectrum profile. The phase transformation observed in XRD was reflected in the changes observed in the photoluminescent behavior of the samples, which emitted light between the blue and green regions. [ABSTRACT FROM AUTHOR]

The rare-earth ion doping in nanocrystals has the advantage on improving the interested properties. As one of rare-earths, the trivalent samarium ion (Sm3+) was used as a dopant. The precursor of Sm3+-doped cadmium ferrite (CdFe2O4) nanocrystals was reacted in water-soluble polymeric nanoreactors as a dispersed phase in miniemulsion, and then calcinated to form doped nanocrystals. The 1% Sm3+-doped nanocrystal in small size exhibited the smaller narrow gap energy and weak photoluminescent emission intensity; which attributed to the positive influences on the photocatalytic degradation. The selected Sm3+-doped spinel ferrite nanocrystals provide a unique catalyzer for organic compound photodegradation. [ABSTRACT FROM AUTHOR]

In order to develop smart concrete with afterglow emission, epoxy resin (EPX) was immobilized with nanoparticles of alkaline earth aluminate (NAEA) as a photoluminescent agent and electrospun polypropylene nanofibers (EPN) as a reinforcement agent. Scanning electron microscope images of EPN displayed diameters of 70–90 nm, whereas transmission electron microscopic images showed that NAEA has diameters of 3–9 nm. To create a transparent sheet that glows in the dark, NAEA were physically immobilized in EPN@EPX composite. CIE Lab and photoluminescence spectrum studies demonstrated that EPN@EPX bars turned greenish upon exposure to ultraviolet (UV) rays and greenish-yellow in a darkened box. The luminous EPN@EPX morphologies and chemical compositions were analyzed using various analytical methods. The resistance to scratching of EPN@EPX bars was monitored to considerably increase with increasing NAEA concentration. The photoluminescence spectrum demonstrated two emission peaks at 437 and 518 nm. Photoluminescent EPN@EPX hybrids with low NAEA content have shown rapid photochromism reversibility. On the contrary, NAEA-rich EPN@EPX bars displayed slow reversibility, glowing in the dark. Superhydrophobicity and UV blockage were found to be significantly improved in the luminescent colorless EPN@EPX hybrids. [ABSTRACT FROM AUTHOR]

Over the last decade, the CO2 reduction reaction (CO2RR) has been increasingly exploited for the synthesis of high‐value raw materials in gaseous or liquid form, although no examples of CO2 fixation in nanoparticle systems have been demonstrated. Herein, CO2 fixation into solid nanomaterials by laser synthesis and processing of gold colloids in water, traditionally considered a green approach leading to ligand‐free nanoparticles without the formation of by‐products, is reported. If carbon monoxide‐rich gold nanoparticles are observable even after synthesis in deionized water, the presence of CO2 derivatives in alkaline water environment leads to C2 and C3 coupling with the production of carboxylic acids as a typical CO2RR fingerprint. While laser processing of preformed gold colloids is selective for C2 coupling, both C2 and C3 coupling to lactic acid are observed during pulsed laser ablation of a gold target. In the latter case, it is demonstrated that it is possible to synthesize photoluminescent organometallic nanocomposites in the blue spectral region with a quantum yield of about 20% under adequate experimental conditions. In this research, new pathways are offered to be explored in energetics, photonics, catalysis, and synthesis at the nanoscale. [ABSTRACT FROM AUTHOR]

The first synthesis of well‐defined poly(methylene‐co‐1,1‐diphenylpropenenylene) (C1‐co‐C1'), equivalent to poly(ethylene‐co‐diphenylbutadiene) copolymers was accomplished by C1 copolymerization of novel diphenylpropenyl triphenyl arsonium ylides (Ph2AY) and dimethylsulfoxonium methylide (Me2SY) using B‐thexylborepane as initiator. All polymerization conditions, including feed ratio, temperature, and reaction time, were optimized. A series of photoluminescent poly(ethylene‐co‐diphenylbutadiene)s were synthesized at different feed ratios, opening a new synthetic horizon for poly(ethylene‐co‐disubstitutedbutadiene) copolymers. Notably, a new C1 segment, arising from a double bond rearrangement, was confirmed by NMR, resulting in an unprecedented two‐monomer three‐structure random terpolymer. An unexpected red‐shift phenomenon in the fluorescence spectra was observed with increasing the ratio of Ph2AY in the copolymer. This shift is attributed to the aggregation of diphenylbutadiene segment, similar to through‐space conjugation (TSC), likely induced by a decrease in the crystallinity of copolymers. Furthermore, another disubstituted allylic triphenyl arsonium ylides, (E)‐2‐phenylbutenyl triphenyl arsonium ylide (MePhAY) was also synthesized and investigated. These additional compounds expand the knowledge and the potential applications of such copolymerization techniques in advanced materials. [ABSTRACT FROM AUTHOR]

Low‐dimensional metal halides (LDMHs) represent a promising class of materials in various luminescent applications because of their self‐trapped exciton (STE) emissions with unique properties such as broad luminescence spectra, large Stokes shift, and high color rendition. LDMHs at the molecular level can be constructed, including 2D layers, 1D chains, and 0D clusters assembled by polyhedra units, all of which exhibit significantly different luminescence properties from 3D MHs. The dimensional regulation of LDMHs has been explored for years, including the choice of organic cations, modulating electron‐phonon coupling effect, and adding external temperature and pressure. Herein, this review discusses the synergy between structural engineering and solvent effects for LDMHs, including the emission mechanisms for LDMHs and the roles solvent molecules play in regulating the dimensions. In addition, challenges and opportunities for LDMHs are discussed to shed light on the future development of novel materials with multifunctional optical properties suitable for practical applications. [ABSTRACT FROM AUTHOR]

This work presents the facile and single‐step hydrothermal synthesis of carbon quantum dots (CQDs) using the Dichrostachys glomerata extract as raw material. CQDs with the highest photoluminescence (PL) were obtained after heating the extract in 4 M NaOH at 200 °C for 7 h. The obtained CQDs exhibit an average size of ca. 4.7 nm, a green‐yellow PL emission independent on the excitation wavelength with contributions located at 478 and 562 nm, a monoexponential decay of their PL lifetime and a PL quantum yield of 18 %. These results indicate that the surface functionalization of sp2 clusters in CQDs is uniform. The antioxidant properties of CQDs were also investigated. CQDs can effectively reduce free radicals like superoxide or oxidants like KMnO4. Moreover, CQDs show a high Cu2+ chelating activity, which is attributed to the abundant carboxylate functions on their surface and may therefore be of high interest in therapeutic applications related to Cu2+ ions overload. [ABSTRACT FROM AUTHOR]

Zero-dimensional heterometallic halide hybrids have emerged as multifunctional emitters, due to their multiple emission features. Herein, high pressure is employed to regulate the multiple emissions of (C9NH20)9[Pb3Br11](MnBr4)2. Pressure-triggered rigidness of [Pb3Br11]5- alters the emission equilibrium of STEs, generating a new blue-shifted STE emission. Meanwhile, [MnBr4]2- contraction promotes the confinement effect to increase the 4D-6A1 transition efficiency. Notably, [Pb3Br11]5- could act as 'antenna' to enhance the Mn2+ emission with blocked back-energy transfer. It indicates that enough incident energy could excite the STE emission and 4D-6A1 transitions simultaneously, which clarifies the conventional understanding of the emission origin at ambient conditions. In zero-dimensional metal halide of (C9NH20)9[Pb3Br11](MnBr4)2, the [Pb3Br11]5- trimer acts as 'antenna' to enhance the [MnBr4]2- emission at high pressure, resolving distinct photoluminescent contributions of individual metal-halogen fragments. [ABSTRACT FROM AUTHOR]

Regulating the crystal structure of metal halides is important to tune their photoluminescence (PL) or govern the potential emergence of diverse physical properties. Here, an exceptional PL phenomenon characterized by dual‐emission bands in the Mn‐based metal halides (C5H6N)2MnBr4 is observed through hydrostatic pressure measurements. The results have confirmed that the dual‐emission bands centered at ≈518 and 650 nm arise from isolated Mn2+ ions and super‐exchange within Mn2+–Mn2+ dimers, respectively. (C5H6N)2MnBr4 displays remarkable piezochromic luminescence, accompanied by a red shift in dual‐emission. This phenomenon can be attributed to the enhancement of crystal‐field splitting energy and the reduction of relaxation from the low‐energy excited state 4T1 to the ground state 6A1. Meanwhile, the dual‐emission exhibits an anomalous increase ≈1.5–3.9 GPa, which is associated with reduced nonradiative losses during energy migration due to the decreased distance between the luminescent centers as a consequence of lattice contraction. Moreover, (C5H6N)2MnBr4 undergoes a phase transition at ≈1.5 GPa, and upon decompression, the high‐pressure phase partially recovers. This study not only provides insights into the luminescent properties of Mn‐based metal halides but also presents a novel approach to the design of multifunctional photoluminescent materials. [ABSTRACT FROM AUTHOR]

Regulating the crystal structure of metal halides is important to tune their photoluminescence (PL) or govern the potential emergence of diverse physical properties. Here, an exceptional PL phenomenon characterized by dual‐emission bands in the Mn‐based metal halides (C5H6N)2MnBr4 is observed through hydrostatic pressure measurements. The results have confirmed that the dual‐emission bands centered at ≈518 and 650 nm arise from isolated Mn2+ ions and super‐exchange within Mn2+–Mn2+ dimers, respectively. (C5H6N)2MnBr4 displays remarkable piezochromic luminescence, accompanied by a red shift in dual‐emission. This phenomenon can be attributed to the enhancement of crystal‐field splitting energy and the reduction of relaxation from the low‐energy excited state 4T1 to the ground state 6A1. Meanwhile, the dual‐emission exhibits an anomalous increase ≈1.5–3.9 GPa, which is associated with reduced nonradiative losses during energy migration due to the decreased distance between the luminescent centers as a consequence of lattice contraction. Moreover, (C5H6N)2MnBr4 undergoes a phase transition at ≈1.5 GPa, and upon decompression, the high‐pressure phase partially recovers. This study not only provides insights into the luminescent properties of Mn‐based metal halides but also presents a novel approach to the design of multifunctional photoluminescent materials. [ABSTRACT FROM AUTHOR]

In this work, five phenanthroline derivatives substituted with different methyl groups have been selected to synthesize β‐diketonate‐based europium complexes to check the influence of the substitutions on the degradation effect of those complexes in poly(methyl methacrylate) (PMMA) films. The photophysical properties of Eu(III) complexes, including absorbance, excitation, and emission have been carefully investigated in solution, solid‐state, and doped in PMMA film. In all these states, the complexes exhibit an impressive red emission at 614 nm with a high photoluminescence quantum yield of up to 85 %. The films have been exposed under outdoor, indoor, and dark storage stability lifetime conditions for 1200 hours. The photoluminescence measurements recorded every 400, 800, and 1200 hours demonstrated that the film containing europium complex with phenanthroline ligand substituted by a high number of methyl groups (Eu(TTA)3L5) showed good photoluminescent stability in indoor and dark conditions, and exhibited better resistance to degradation in outdoor conditions compared to other complexes. This study has proved that phenanthroline ligands could be tuned chemically leading to better stability of those types of complexes in films which can be end‐used for future stable optoelectronic devices such as luminescent solar concentrators. [ABSTRACT FROM AUTHOR]

As a class of emerging photoluminescent materials, hybrid halide crystals have drawn research attention for their potential application in the fields of light‐emitting, security, and waveguide. Nevertheless, hybrid halide crystals containing antimony with long‐term stability and tunable light emission are still increasingly in demand. In this work, serial new hybrid halide crystals (BZA)2ZnCl4·2H2O:xSb3+ (x = 0–0.2, x represents the reaction ratio) and (BZA)2SbCl5 are synthesized (BZA = 2,4‐diamino‐6‐phenyl‐1,3,5‐triazine). In (BZA)2ZnCl4·2H2O:xSb3+ crystals, Sb3+ cations replace partial Zn2+ cations to form [SbCl4]− tetrahedron. Red light emission caused by the substitution of Sb3+ for Zn2+ enhances as the doping rate increases, resulting in the tunable emission from light blue to pink and finally to dark red. There are two kinds of Sb3+ in (BZA)2SbCl5 crystal. Sb(1) has a sixfold coordination with Cl to form a [Sb(1)Cl5]∞ 1D zigzag chain. Sb(2) atom adopts a fivefold coordination with Cl and is separated from each other by BZA+ cations. (BZA)2SbCl5 crystal shows bright orange‐yellow light emission with a photoluminescence quantum yield of 45%. Moreover, the organic–inorganic hybrid metal halide crystals containing antimony have excellent long‐term stability, with phase and luminescence keeping nearly unchanged after more than six months in ambient air. [ABSTRACT FROM AUTHOR]

High-efficiency narrowband near-ultraviolet (NUV) organic light-emitting diodes with high color purity have currently encountered great challenges. Here, using butyl (Bu) and cyanogen (CN) substituted strategy in the simplest polycyclic aromatic hydrocarbons of indolocarbazole (ICz), two simple emitters of BuICz and BuICzCN were demonstrated. This simple strategy was observed to enable both emitters to realize NUV emission at 380–381 nm with a small full width at half maximum (FWHM) of 21–23 nm and high photoluminescent quantum efficiency of 50%–59% in toluene solution. Furthermore, the BuICzCN doped devices exhibited a slightly blueshifted narrowband NUV electroluminescence at 388 nm with a small FWHM of 32.3 nm but a higher external quantum efficiency of 3.92% in comparison with the BuICz doped devices. This work provides a path to realize high-performance narrow-band NUV emission. [ABSTRACT FROM AUTHOR]

Two new lanthanide-complexes based on the 5-nitropicolinate ligand (5-npic) were obtained and fully characterized. Single-crystal X-ray diffraction revealed that these compounds are isostructural to a Dy-complex, previously published by us, based on dinuclear monomers link together with an extended hydrogen bond network, providing a final chemical formula of [Ln2(5-npic)6(H2O)4]·(H2O)2, where Ln = Dy (1), Gd (2), and Tb (3). Preliminary photoluminescent studies exhibited a ligand-centered emission for all complexes. The potential antitumoral activity of these materials was assayed in a prostatic cancer cell line (PC-3; the 2nd most common male cancerous disease), showing a significant anticancer activity (50–60% at 500 μg·mL−1). In turn, a high biocompatibility by both, the complexes and their precursors in human immunological HL-60 cells, was evidenced. In view of the strongest toxic effect in the tumoral cell line provided by the free 5-npic ligand (~ 40–50%), the overall anticancer complex performance seems to be triggered by the presence of this molecule. [ABSTRACT FROM AUTHOR]

Five coordination compounds of the general formula [LnL2(NO3)3]n (Ln3+ = Eu (I), Sm (II), Tb (III), Dy (IV), and Gd (V)) based on 2-[((4-chlorophenyl)amino)methylene]-5,5-dimethylcyclohexane-1,3-dione (L) are synthesized. The crystal structures of the ligand and complex III are determined by X-ray diffraction (XRD) analysis of single crystals (CIF files CCDC no. 2298715 (L) and 2298716 (III)). Complex III is polymeric due to the bidentate-bridging coordination of the ligand by the oxygen atoms of the cyclohexanedione fragment, and the coordination number of the central atom is ten. According to the powder XRD data, all synthesized polycrystalline compounds are isostructural to the single crystals of complex III. The photoluminescence properties of the ligand and coordination compounds in the polycrystalline state are studied. The energy transfer from the ligand to lanthanide(III) ion is shown to proceed via the "antenna" mechanism in the case of the europium(III), samarium(III), and terbium(III) compounds. Among the series of the complexes, the highest quantum yield is observed for compound I (21.9%), and the sensitization efficiency of the europium(III) complex is 43.5%. [ABSTRACT FROM AUTHOR]

Colloidal quantum dots (QD), the material discovered and fostered by laureates of Nobel Prize in Chemistry at 2023, exhibit impressive color purity and light conversion efficiency, are one of the most promising luminescent candidates in wide color gamut display application. Although the QD‐based color conversion techniques are gaining momentum in display industry, integration of QD into LED as on‐chip form still remain to be realized. The allocation of QD layer adjacent to the GaN blue LED light source are considered as the most viable, convenient, and efficient arrangement of adopting QD into photoluminescent scenarios. However, the extremely harsh working conditions QD endured in LED pose immense challenge and barrier to be surmounted. Herein, through bandgap engineering and overgrowth of silica‐aluminum oxide on QD, for the first time, we demonstrate mass‐producible LED chips integrated with QD as photoluminescent color converters via traditional dispensing process. Compared to conventional β‐sialon phosphors, the LED device incorporated with QD show comparable luminous efficacy and reach a wider benchmark of 105.1% NTSC and 98.5% DCI‐P3 color gamut. In addition, our devices exhibit decent lifetime under both working and storage conditions. Typically, while deployed under 60 °C and 90% relative humidity, our 2604 chip charged with a 20 mA working current maintains CIE 1931 color shift within ± 0.015 and luminosity reduction less than 10% after 1000 h continuous run. [ABSTRACT FROM AUTHOR]

Two new Schiff base compounds of N‐{2‐[(E)‐сyclohexyliminomethyl]phenyl}‐4‐methylbenzenesulfonamide, N‐{2‐[(E)‐(4‐сyclohexylphenyl)iminomethyl]phenyl}‐4‐methylbenzenesulfonamide and their Zn(II) complexes have been synthesized and characterized by elemental analysis, FT‐IR and UV–Vis spectra, and single crystal X‐ray determination. In both complexes, Zn2+ ions have a tetrahedral environment with two nitrogen atoms of the tosylamide groups and two nitrogen atoms of the imine fragment. Time‐dependent density functional theory calculations have been performed on two zinc(II) complexes in order to assign their experimental UV–visible absorption bands. Zinc(II) complexes showed thermal stability up to 335–340°C under a nitrogen atmosphere by thermogravimetric analysis (TGA). The photoluminescent spectra show that both Zn(II) complexes in the solid state at room temperature emit blue luminescence with high emission quantum yields of 20% and 29%. The doped devices with configurations of indium tin oxide (ITO)/poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)/N,N′‐Di(1‐naphthyl)‐N,N′‐diphenyl‐(1,1′‐biphenyl)‐4,4′‐diamine (NPD)/4,4′‐N,N′ ‐dicarbazolebiphenyl (CBP):Zinc(II) complex (5%)/1,3,5‐tris(N‐phenylbenzimidazole‐2‐yl) benzene (TPBI)/LiF/Al have been fabricated and investigated. The doped device based on the complex with the сyclohexylphenyl substituent of the ligand showed the best electroluminescent characteristics with maximum brightness Lmax of 3415 cd/m2, maximum current efficiency of 2.8 cd/A, and power efficiency of 1.9 lm/W, while the doped device with emitter on the base of the complex with the сyclohexyl substituent showed slightly worse electroluminescence (EL) performance with Lmax of 2105 cd/m2, maximum current efficiency of 2.1 cd/A, and power efficiency of 1.6 lm/W. [ABSTRACT FROM AUTHOR]

Dyes derived from benzothiazoles are an important class of heterocycles which have remarkable photophysical properties. New photoluminescent 2-phenylbenzothiazole derivatives containing different functional groups were synthesized in high yields and used for silylated derivatives synthesis. The new photoactive compounds were fully characterized and their photophysical properties were investigated. The absorption and fluorescence spectra of the benzothiazoles and their silylated derivatives were evaluated in a series of organic solvents. The results showed that the benzothiazoles present absorption in the ultraviolet range and emission in the blue region with moderate quantum yields and large Stokes shift. The solvatochromism of these compounds was investigated by using Lippert and ET(30) Dimroth-Reichardt empirical solvent polarity scales. The dipole moments obtained by Bakshiev and Kawaski-Chamma-Viallet equations revealed that the excited states were more polar than the ground states. [ABSTRACT FROM AUTHOR]

New Janus-type compounds were synthesised with two different hemispheres structures and properties. The structures contain cyanobiphenyl units linked with 3,4,5-tribenzyloxybenzene or 3,4,5-tridecyloxybenzene units. Also, the influence of the 1,3,4-thiadiazole heterocycle was studied. The mesomorphic properties were studied by differential scanning calorimetry, polarised light optical microscopy and thermal gravimetric analysis. The mesophases obtained depend on the structure of the hemispheres, even obtaining mesophases different from the initial ones. The new materials synthesised presented photoluminescent properties, which were studied in solution. [ABSTRACT FROM AUTHOR]

Using a two-solvent interdiffusion technique, the ligand tpatpy that possesses aggregation-induced emission (AIE) properties was coordinated to Cd2+ to construct two coordination polymers under conditions that differed only by reaction temperatures of 30 °C and 0 °C for 1 and 2, respectively. Single-crystal X-ray diffraction studies revealed the key structural differences were that the metal centers in 1 were five-coordinate, versus four-coordinate in 2. Thus, this system could be tuned by controlling the temperature during synthesis. UV-visible spectroscopy (UV-Vis), infrared spectroscopy (IR), powder X-ray diffraction (PXRD), thermogravimetry (TG), and the fluorescence of 1 and 2 are discussed to provide a comprehensive discussion of physical and electronic properties. [ABSTRACT FROM AUTHOR]

The main aim of this work is to demonstrate that well-defined methacrylate-based copolymers with oligoethylene glycol side chains and functional groups such as thiol and glycidyl, obtained by photo-initiated reversible addition-fragmentation chain transfer (RAFT) in ethanol, are highly suitable as templates in the synthesis and protection of ZnO quantum dots (ZnO QDs) with remarkable photoluminescent properties. While the affinity of thiol groups to metallic surfaces is well established, their interaction with metal oxides has received less scrutiny. Furthermore, under basic conditions, glycidyl groups could react with hydroxyl groups on the surface of ZnO, representing another strategy for hybrid synthesis. The size and crystalline morphology of the resulting hybrids were assessed using DLS, TEM, and XRD, indicating that both polymers, even with a low proportion of functional groups (5% mol) are appropriate as templates and ligands for ZnO QDs synthesis. Notably, thiol-containing polymers yield hybrids with ZnO featuring excellent quantum yield (up to 52%), while polymers with glycidyl groups require combination with the organosilane aminopropyl triethoxysilane (APTES) to achieve optimal results. In both cases, these hybrids exhibited robust stability in both ethanol and aqueous environments. Beyond fundamental research, due to the remarkable photoluminescent properties and affordability, these hybrid ZnO QDs are expected to have potential applications in biotechnology and green science; in particular, in this study, we examined their use in the detection of environmental contaminants like Fe2+, Cr6+, and Cu2+. Specifically, the limit of detection achieved at 1.13 µM for the highly toxic Cr6+ underscores the significant sensing capabilities of the hybrids. [ABSTRACT FROM AUTHOR]

The structural characterization of 3,4-dichloroisothiazole-5-carboxylic acid is performed for the first time along with the preparation of the first coordination compound based on it - a mixed-ligand europium(III) complex with 3,4-dichloroisothiazole-5-carboxylic acid and 1,10-phenanthroline. The coordination compound is characterized by the elemental analysis, single crystal and powder X-ray diffraction (XRD), and IR spectroscopy. According to the single crystal XRD data, the obtained complex is a binuclear compound with the formula [Eu2L6(phen)2(H2O)2]·6H2O. Its structure corresponds to the Chinese lantern type. The isothiazole derivative exhibits both monodentate and bidentate-bridging coordinations binding europium ions. The photoluminescent properties of a polycrystalline sample of the complex are studied: the luminescence quantum yield is 23%, the excited state lifetime is 0.8 ms. [ABSTRACT FROM AUTHOR]

The in situ deposition of emerging organic–inorganic metal halides (OIMHs) films on glass or stretchable substrates has been challenging, and no methodology has been reported to achieve this goal. The aerosol‐assisted chemical vapor deposition technique using an antisolvent‐enhanced crystallization process (AEC–AACVD) is a simple, cost‐effective, scalable, and high‐throughput technique operated under ambient atmosphere and pressure. The AEC–AACVD technique (an all‐green chemistry methodology) is used in this work to deposit TPA2MnCl2Br2 luminescent films on glass and highly stretchable elastomer substrates. The effect of using different antisolvents on the structural, morphological, and photoluminescent (PL) characteristics of films deposited on glass is reported. It is found that the intensity of the characteristic green emission peaks at 511 nm for this OIMH, improving with the antisolvent application. The TPA2MnCl2Br2 films deposited using a mixture of antisolvents result in the maximum emission intensity when deposited on stretchable substrates, maintaining their overall PL characteristics. The processability, scalability, and performance reported here for these films prove their potential application in the next generation of OIMH‐based optoelectronic technologies. [ABSTRACT FROM AUTHOR]

We demonstrate the use of copper arylamide complexes as efficient photoluminescent mechanophores to design deep-red/near-IR emissive polymers showing reversible changes in photoluminescence intensity in the red/near-IR region in response to mechanical stretching. The mechanoresponse was repeatable over 30 cycles, showing a measurable increase of photoluminescence intensity even at a small applied stress of ca. 0.01 MPa. We demonstrate the potential of using conformationally dynamic copper amide complexes as sensitive and reversible mechanophores for near-IR imaging; systematic control over the emission range was achieved using amide modification. [ABSTRACT FROM AUTHOR]

Atomically precise metal nanoclusters (NCs) emerge as fascinating synthons in self‐assembled materials. The self‐assembly of metal NCs are highly sensitive to the environment because they have an inorganic‐organic hybridized structure and a relatively complicated conformation. Here, it is shown that when confined in crowded colloids, a water‐soluble Ag9‐cored nanocluster (Ag9‐NC) can self‐ assemble into ultra‐long (up to millimeters) and photoluminescent ribbons with high flexibility. The ribbon contains rectangularly organized columns of Ag9‐NCs and can undergo secondary self‐assembly to form bundled and branched structures. Formation of ribbons is observed in all the tested colloids, including lyotropic liquid crystals and disordered, three‐dimensional network. The high viscosity/elasticity of the crowded colloids weakens gravity‐induced sedimentation of the ribbons, leading to the formation of an interesting class of inorganic‐organic composite materials where the hard Ag‐containing skeleton strengthens the soft matter. The simultaneously occurring symmetry breaking during the self‐assembly of Ag9‐NCs gives uncontrolled supramolecular chirality, which can be tuned through the majority rule and soldier‐and‐sergeant rule by the introduction of chiral seeds. The regulated chirality and the intrinsic photoluminescence of the Ag9‐NCs ribbons impart the composite material circularly polarized luminescence, opening the door for a variety of potential applications. [ABSTRACT FROM AUTHOR]

This study focuses on the fabrication of polymer nanocomposite films using polyvinyl alcohol (PVA)/graphene quantum dots (GQDs). We investigate the relationship between the structural, thermal, and nanoscale morphological properties of these films and their photoluminescent response. Although according to X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and differential thermal analysis (DTA), the incorporation of GQDs does not significantly affect the percentage crystallinity of the PVA matrix, for a range of added GQD concentrations, atomic force microscopy (AFM) showed the formation of islands with apparent crystalline morphology on the surface of the PVA/GQD films. This observation suggests that GQDs presumably act as nucleating agents for island growth. The incorporation of GQDs also led to the formation of characteristic surface pores with increased stiffness and frictional contrast, as indicated by ultrasonic force microscopy (UFM) and frictional force microscopy (FFM) data. The photoluminescence (PL) spectra of the films were found to depend both on the amount of GQDs incorporated and on the film morphology. For GQD loads >1.2%wt, a GQD-related band was observed at ~1650 cm−1 in FT-IR, along with an increase in the PL band at lower energy. For a load of ~2%wt GQDs, the surface morphology was characterized by extended cluster aggregates with lower stiffness and friction than the surrounding matrix, and the PL signal decreased. [ABSTRACT FROM AUTHOR]

Context: Boron nitride quantum dots (BNQDs) are emerging as promising multifunctional nanomaterials for renewable energy and optoelectronics owing to their versatile properties. However, rational design principles to tailor their photoelectric and photoluminescent capabilities remain scarce. This study employs density functional theory (DFT) to provide fundamental insights into using urea, thiourea, and PPD ligands to modulate the bandgap, charge transfer dynamics, and recombination processes of BNQDs. Modeling explains that incorporating specific ligands enables visible light absorption, spatial charge separation, continuous photocatalytic cycling, and high quantum yields in BNQDs. The structure-property relationships established pave the way for targeted synthesis of high-performance BNQD photocatalysts and light emitters. Methods: This investigation utilized density functional theory (DFT) with the B3LYP functional and 6-31G(d,p) basis set to optimize the geometries of pristine and ligand-functionalized boron nitride quantum dots (BNQDs). The absorption spectra were generated using time-dependent DFT (TDDFT). A Ti38O76 cluster modeled the TiO2 substrate. The cpcm solvation model in Gaussian 09 defined the toluene solvent. Cohesive energies, charge transfer lengths, recombination rates, and conversion efficiencies were calculated to establish structure-property relationships. Multiwfn analyzed the charge densities. The modeling provides insights into tuning BNQD photocatalytic and photoluminescent properties using specific ligands. [ABSTRACT FROM AUTHOR]

New photoluminescent materials have numerous possibilities in many different areas from technological applications to contemporary glass art and design, encouraging the development of new forms and products. Glass luminescent materials, known for their exceptional durability and recyclability, position glass as an ideal solution for fostering a more sustainable future. In recent years, white luminescence in glass and ceramics has been the subject of several investigations about its possible application in white light‐emitting diodes (WLED). Color coordinates and CIE chromaticity diagrams serve as valuable tools to represent and define the range of luminescent colors achievable in a particular composition. These aid in understanding wheter a composition can be used to produce white luminescence or various other colors. In this study, a soda‐lime silicate glass composition was doped with a mixture of different lanthanide oxides to increase the luminescence color palette. The same glass sample can also present different colors by changing the excitation light, allowing higher tunability of luminescent colors. It was effectively demonstrated the extensive spectrum of colors produced, which was represented through luminescence color coordinates for all synthesized glasses. Moreover, the possibility of detecting if an excited state process is occurring was studied by calculating the lanthanides factors and comparing them with those used in the glass synthesis. Nevertheless, it is shown that the energy transfer process has to be significant to influence the color coordinates and the calculation of the factors. [ABSTRACT FROM AUTHOR]

Among the practical applications of Quantum Physics, photoluminescence has stood out in different contexts in Engineering and Architecture. Due to the photoelectric effect, certain substances emit photons after being exposed to solar energy. In research in Mexico and Europe, these substances were applied to obtain a photoluminescent effect on bicycle paths. The objective of the research is to investigate the behavior of polymeric residues with the luminescent effect of rare-earth materials in the production of concrete artifacts to illuminate pedestrian and cyclist paths. The concrete blocks were produced with the addition of polymeric recycling waste and luminescent materials, exposed to solar radiation, and tested for mechanical strength. The results of the experiments showed that the polymer residue in concrete significantly increases photon emission, especially when it is processed by extrusion. Although the mixture of photoluminescent materials and polymers reduces the strength of concrete, it still met research objectives for a product meant to illuminate pedestrian and cyclist paths. [ABSTRACT FROM AUTHOR]

For ecologically friendly and energy-efficient solid-state light sources, phosphors with low color-correlated temperatures (CCTs) and high color rendering indices (CRIs) are greatly desired. Herein, a co-precipitation method is used to modulate the fluorescence color of ZnO nano- material for bright multi-color light emitting diodes (LEDs) applications. The structural, thermal, morphological and optical properties of ZnO nanomaterials have been studied. Thermogravimetric analysis (TGA) of the as-synthesized nanomaterials reveals their good thermal stability whereas XPS analysis confirms their chemical states. We demonstrate that after combining ZnO with Ag2O and MnO2, the nanocomposite can attain extraordinary luminous tunability as realized by the photoluminescence (PL) properties of the nanomaterials. The estimated Commission Internationale de l'Eclairage (CIE) color coordinates indicate that ZnO, the blue color phosphor can be tuned to orange-red color phosphor (ZnO/Ag2O and ZnO/MnO 2) and to white color phosphor (ZnO/Ag2O/MnO 2) exhibits fairish color rendering index (CRI) of 84, after composited with Ag2O and MnO2. Finally, the ZnO/Ag2O, ZnO/MnO2 and ZnO/Ag2O/MnO2 nanocomposites have the potential to be utilized as phosphor materials in warm white LED applications because of their extremely pure, robust stability and tunable emission colors. Our findings can be used as a new benchmark for the identification of new phosphors and the tunability of their luminescent color for solid-state lighting applications. In this study, it can be observed that photoluminescence emission of ZnO nanostructure can be tuned after composited with Ag2O and MnO2. The tunability can be represented by Commission Internationale d'Eclairage (CIE) chromaticity diagram. From CIE diagram, it can be seen that photoluminescent colors acquired by ZnO nanostructures can be enhanced after composited with Ag2O and MnO2, and therefore making them suitable candidate to be used in warm white light LED applications. [ABSTRACT FROM AUTHOR]

The paper presents the fabrication and characterization of [CuI(L)][sub n] thin films, where L represents various alkylpyridine ligands including 4-methylpyridine, 3-methylpyridine, 2-methylpyridine, 4-[sup t]butylpyridine, 3,4-dimethylpyridine, and 3,5-dimethylpyridine. The thin films were synthesized by exposing the corresponding ligands to CuI thin films through vapor deposition. The coordination reactions occurring on the films were investigated using PXRD and time-dependent photoluminescence spectroscopy, and a comparison was made between the structures of the thin films and the corresponding powder phases. The films showed primarly blue emission (λem = 457-515 nm) and polymeric structures with excited state lifetimes ranging from 0.6 to 5.5 μs. Significantly, the studied compounds exhibited fast reversible luminescence quenching when exposed to vapors of dichloromethane and dibromomethane (15 and 30 min respectively), and the luminescence was restored upon reexposure to the alkylpyridine ligand (after 20 min). These findings indicate that these thin films hold promise for applications as sensors (with sensitive and reversible detection capability) for volatile halogen-based compounds (VHC). [ABSTRACT FROM AUTHOR]

Photoluminescent down-shifting Silicon (Si) and Zinc Oxide (ZnO) Quantum Dots (QDs) were synthesized and employed in spectral converter layers to increase the photovoltaic performance of commercial solar cells. Poly-methyl-methacrylate (PMMA) was used as a matrix host to provide a transparent support for the quantum dots. The thickness of the photoluminescent QD layers and the particle concentration in the polymer were optimized to reduce reflectivity and increase the power generation. Different luminescent films' configurations were tested on fully functional solar cells, including single type of QD (Si or ZnO) layer and double layer of QDs (Si + ZnO). The colloidal QDs presented optical bandgaps of 2.97 eV and 3.40 eV for the Si QDS and ZnO QDs, respectively, difference that was advantageous for a double-layer configuration. The absorption of both Si QDS and ZnO QDs was mainly in the UV region, while their luminescence consisted of broad bands centered at 525 nm and 545 nm, respectively, providing an attractive stokes shift to be employed as spectral converter layer. The combination of UV absorption, downshifted emission, and reflectivity reduction by the QD-based layers produced improvements in the power conversion efficiencies of commercial silicon solar cells from 14.42 to 15.36%, which represent an overall improvement of ~ 6.5%. The collected results represent a promising strategy to improve the photovoltaic performance of new and existing devices. [ABSTRACT FROM AUTHOR]

This study investigated the structural, morphological, and photoluminescent properties of ZnO nanopowders doped with Mo and V, which were synthesized using pulsed laser reactive technology. The nanoparticles' structure, shape, and size were determined using electron microscopy and X-ray diffractometry. The photoluminescence properties of the Mo- and V-doped ZnO nanopowders in different gas environments were studied, revealing that changes in the gas environment led to significant alterations in the intensity and deformation of the photoluminescence spectra. All samples exhibited strong emission bands in the UV range and a broad, non-elemental emission band in the visible region ranging from 410 to 600 nm. Decomposing the photoluminescence spectra into elementary bands revealed peaks at 430 and 520 nm. Chromaticity diagrams of the photoluminescence light emitted by the nanopowders were obtained, and it was found that the color coordinates varied depending on the gas environment, which could be useful in gas sensors. [ABSTRACT FROM AUTHOR]

Attempt has been made here to synthesize yttrium doped (Ba 0.90 Sr 0.10)(Fe 1-x Y x)O 3-δ (x = 0 – 0.20) oxides by sol-gel technique to study the influence of yttrium with regard to phase(s), strain, Raman and photoluminescent behaviour. It exhibits perovskite-type cubic and mixture of cubic and orthorhombic phases for x = 0 - 0.10 and > 0.10, respectively. The cubic lattice parameter increases linearly ( a ∼4.019 - 4.054 Å, space group Pm3 m, Z = 1) with yttrium, leading to lattice expansion. Similarly, the average bond length also increases linearly (d c ∼ 2.426 - 2.447) with 'x'. The bond angles along O-B-O and B-O-B are deviated due to the tilting and rotation of BO 6 octahedra. Raman spectra reveal no band formation for the cubic phase of composition but appear for orthorhombic phase with x > 0.10. It consist bands at ∼130, 148, 222, and 372, and a broad band at ∼690 cm-1, associated with Ba/Sr bonded vibration, symmetric stretching of oxygen, and occurrence of oxygen vacancies. The photoluminescence spectra reveal peaks at ∼339, 411, 456, 486.5, and 525.5 nm (say; for x = 0.05), assigned to charge transfer transition O2p to iron and/or yttrium, interface trapping-induced radiative defects as well as shallow surface defects, and huge oxygen vacancies with trapped electrons, etc. These findings make materials useful in membrane technology. [ABSTRACT FROM AUTHOR]

Pure ZnO particles, doped and co‐doped with Cu2+ and Mg2+ ions, were obtained by the simple sonochemical method. The wurtzite hexagonal structure was confirmed by X‐ray diffraction (XRD) patterns. The images obtained by field emission scanning electron microscopy (FE‐SEM) showed irregular and more agglomerated particles with the increase of Cu2+ and Mg2+ ions concentration in the ZnO lattice, with the average diameter of particles in the range of 57.23–170.77 nm. The photocatalytic activity was investigated by decolorizing the methylene blue (MB) dye under ultraviolet C (UVC) light irradiation which indicates that 1% Mg‐doped ZnO particles have better the photocatalytic activity than the other samples, and presented the highest kinetic constant value. The co‐doped samples showed a reduced global surface area which did not favor the good photocatalytic performance. The sacrificial agents showed that OH• radicals are the main species involved in the photocatalytic activity of this system and defects generated in the ZnO lattice promoted photoluminescent emission in the red and green regions. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) have been quickly extended for nanomedicine uses because of their multiple applications, such as bioimaging, sensors, and drug delivery. However, the interest in increasing their photoluminescence properties is not always accompanied by cytocompatibility. Thus, a knowledge gap exists regarding their interactions with biological systems linked to the selected formulations and synthesis methods. In this work, we have developed carbon dots (CDs) based on poly (ethylene imine) (PEI) and chitosan (CS) by using microwave irradiation, hydrothermal synthesis, and a combination of both, and further characterized them by physicochemical and biological means. Our results indicate that synthesized CDs have sizes between 1 and 5 nm, a high presence of amine groups on the surface, and increased positive ζ potential values. Further, it is established that the choice and use of different synthesis procedures can contribute to a different answer to the CDs regarding their optical and biological properties. In this regard, PEI-only CDs showed the longest photoluminescent emission lifetime, non-hemolytic activity, and high toxicity against fibroblast. On the other hand, CS-only CDs have higher PL emission, non-cytotoxicity associated with fibroblast, and high hemolytic activity. Interestingly, their combination using the proposed methodologies allow a synergic effect in their CDs properties. Therefore, this work contributes to developing and characterizing CD formulations based on PEI and CS and better understanding the CD's properties and biological interaction. [ABSTRACT FROM AUTHOR]

Poly(p-phenylene vinylene) (PPV) is one of the earliest discovered photoluminescent polymer with regular structure and high fluorescence quantum yield. Many methods have been reported for the synthesis of PPV, but most of them are not feasible for controlling the molecular weight and molecular weight distribution of PPV. Confining chemical reactions in porous channels is a common method to control the chemo- and stereo- selectivity and modulate the reaction rate. Therefore, many methods have been developed for loading the catalysts inside porous materials to regulate chemical reactions and polymerizations. To this end, palladium catalysts were selectively loaded into the pores of mesoporous silica materials with different pore sizes for the controlled synthesis of PPV. Six types of mesoporous palladium nanoreactors were prepared using three different types of mesoporous silica materials (dendritic mesoporous silica nanospheres, SBA-15, and low aspect ratio SBA-15). Their stable mesoporous structure and efficient loading of palladium catalysts in the pores were determined by nitrogen adsorption-desorption analysis and transmission electron microscopy. The palladium content was measured by plasma emission spectroscopy. Heck coupling polymerizations between dihexoxy substituted diiodobenzene and divinylbenzene monomers were thus ushered inside the nanopores to get the molecular weight of the PPV product controlled through the spatial confinement effect of the pores. The reactions were carried out at 135 °C for 3 d and the polymeric products were directly subjected for structural analysis. Fourier transform infrared spectroscopy showed that the obtained PPV consisted of para-substituted benzene rings and trans-ethylene groups, similar to the literature reported ones. The molecular weight of PPV was measured by gel permeation chromatography. It can be found that PPV with narrower molecular weight distributions was obtained in six kinds of palladium-loaded nanoreactors in comparison with that obtained in homogeneous catalytic system. The dispersity of the PPV obtained through this strategy reached as low as 1.53. [ABSTRACT FROM AUTHOR]

Chiral self‐sorting is essential for the establishment of structures in nature and chemistry. Owing to similarities among recognition sites of enantiomers and shared conformational labilities, high‐fidelity chiral self‐sorting constitutes a substantial challenge. Coordination polymers (CPs) with a high surface area and chemical tunability have potential applications in luminescent probes and optoelectronics. However, it is difficult to synthesize micro‐/nano‐scale CPs with high conductivity for optoelectronics. Here, a series of perylene diimide (PDI)‐based CPs with large π‐planes is synthesized by tuning ligands for use in various sensors. A cadmium (Cd)‐based coordination polymer with leucine (LeuPDI‐Cd) exhibits a unique chiral self‐recognition phenomenon when two enantiomeric ligands are mixed with the metal source because homochiral CPs are thermodynamically more stable than their heterochiral analogs. In addition, photoluminescent (PL) LeuPDI‐Cd CPs can detect ethylenediamine with high sensitivity and selectivity. Micro‐/nano‐sized CPs with methionine (MetPDI‐Cd) are used in photodetectors and chemiresistive sensors for the detection of toxic phenylhydrazine. Theoretical calculations reveal that the enhanced conductivity is related to the reduced energy gap, which occurs after adsorption of phenylhydrazine onto the CP surface. These results demonstrate the feasibility and versatility of PDI‐based CPs for applications in PL sensing and optoelectronics through the tuning of PDI ligands. [ABSTRACT FROM AUTHOR]

Photochromic inks have showed many drawbacks such as low efficiency, high price and low durability. Self-healable inks have proved to be highly photostable and durable. Ultraviolet-stimulated photochromic hydrogels with self-healing characteristics were produced and used to create an authentication stamp. An organic–inorganic hybrid hydrogel ink was developed by the synthesis of nanoparticles of lanthanide-doped aluminate (NLdA), and the dispersion of those nanoparticles in a mixture of cellulose nanofibers (CNF) and sodium alginate (SA). Transmission electron microscopy analysis of NLdA revealed sizes of 8–12 nm, whereas the diameters of cellulose nanofibers ranged from 33 to 63 nm. The mechanical strength of the sodium alginate bulk was enhanced by synthesizing CNF and using it as nanofiller and reinforcement agent in the CNF/SA hybrid hydrogel. Transparent prints need NLdA to be dispersed evenly throughout the cellulose nanofibers/sodium alginate hydrogel without aggregation. The thermofixation process efficiently imprinted the photochromic ink into the paper surface. By directly stamping a homogeneous photochromic film onto paper surface, we were able to achieve transparency. Both photoluminescent spectral and CIE (Commission internationale de l'éclairage) Lab measurements confirmed that the colorless film turns green when illuminated with UV. Upon excitation at 370 nm, the emission wavelength of the glowing paper sheets was monitored at 518 nm. The morphology of the stamped sheets was analyzed using scanning electron microscope, infrared spectroscopy and X-ray fluorescence, energy-dispersive X-ray. The hydrogel ink prints showed highly reversible fluorescent-based photochromism. The mechanical properties of prints were tested, and the rheology of the glowing hydrogel was also studied. The currently available NLdA@CNF/SA hydrogel ink provides a reliable anticounterfeiting technology applicable to many types of products. [ABSTRACT FROM AUTHOR]

Quantum-confined CdTe nanoplatelets (NPL) are synthesized in colloidal solutions. The formation, growth, and transformation of 2D NPLs are monitored using UV-visible absorption PL spectroscopy and transmission electron microscopy. The luminescence intensity of NPL dependences on the temperature and injection of precursors is shown. It is found that the luminescence spectra shift to the long-wavelength region with increasing temperature due to an increase in the thickness of the NPL. The dependence of the band gap on the thickness of the NPL is shown. The band gap is determined by the thickness and number of layers. The dependence of the concentration of precursors in the reaction mass and the kinetics of NPL growth are shown. The excitation of defect states luminescence depends on the coordinating oleic ligand. The crystal structure of the CdTe NPL was analyzed via the electron diffraction pattern (ED), which allows a comparative conclusion about the crystal structure of the obtained NPL samples. [ABSTRACT FROM AUTHOR]

Functional biomacromolecular luminophores have attracted increasing interest. Based on the concept of aggregation-induced emission (AIE), the restricted intramolecular rotation (RIR) strategy is widely used to design dyes, which generally focuses on the luminous molecular structures and their stacking modes. However, little effort has been made to reveal the interactions between the embedded fluorophores and their microenvironments. Herein, a series of polysaccharide macromolecules with multicolor emissions were obtained by crosslinking oxidized sodium alginate (OSA) with aminopyridine (Apy). Based on the para- and ortho-substituent OSA chains in the Apy units, their varying steric hindrances resulted in an enhanced fluorescence quantum yield (QY) of 0.98% for OSA-5-Apy and 15.62% for OSA-3-Apy after grafting the Apy units. With further increase in the Apy content, the rigidity of the polysaccharide matrix was improved by the covalently cross-linked bonds and hydrogen bonds, which further enhanced the fluorescence QY of OSA-5-Apy from 0.98% to 5.25%. The corresponding contributions of the restrictions to the emission intensities were elaborately examined by introducing Ca2+. Moreover, based on their complexation with Ca2+, colorful photoluminescent gels in different forms, such as Rubik's cube and fiber, were prepared using OSA-3-Apy fluorescence macromolecules, which is promising in the biomedical and engineering fields. [ABSTRACT FROM AUTHOR]

Green synthetic approaches aid control of physicochemical properties of nanoparticles and decrease the environmental footprint of the nanoparticles. Herein, novel synthesis of ZnO nanoparticles (NPs) using natural surfactants and sequential investigation of their optical, physicochemical and photocatalytic properties are conducted. This work utilizes β-cyclodextrin (βCD) and honey as surfactants during the production process. It is demonstrated that these natural surfactants have the ability to control size, shape, crystalline phase growth and dispersion of NPs (denoted as ZnO-C and ZnO-H). Subsequent coupling of ZnO NPs with Ag to form the binary nanostructures (ZnO-xAg, ZnO-C-xAg and ZnO-H-xAg) further assists controlling their physicochemical properties. With a variation of Ag NPs loading, the 3 wt% Ag loaded nanophotocatalysts were more efficient and their associated properties were revealed by various characterization techniques. Nanoparticles of different shapes were fabricated with a surface area of up to 10 m 2. g − 1 and crystalline sizes of 9.38 nm. Photoluminescent spectroscopy indicated that Ag nanoparticles enhanced the life span of electron-hole pairs. Thus, photodegradation of bromophenol blue (BPB) indicated enhanced NPs photoactivity upon modification with CD, honey, and Ag NPs. BPB photodegradation was > 99.84% using ZnO-H-3Ag with reaction rates of k 0 app = 518.8 × 10 − 2 min − 1 and up to 75% total organic carbon was removed by ZnO-H-3Ag at a rate of 8.19 × 10 − 3 min − 1 . [Display omitted] • Green synthesis of Ag-ZnO nanoparticles. • Honey and β-cyclodextrin act as natural surfactants for particle size, crystalline facet control and particle dispersion of ZnO. • Honey-modified ZnO NPs have smaller particle size, better distribution and superior photocatalytic removal of bromophenol Blue (>99%). • Pseudo kinetics for the degradation of bromophenol blue were determined. • Degradation mechanism of bromophenol blue proposed. [ABSTRACT FROM AUTHOR]

Nitrobenzene (NB) is a highly toxic chemical and a cause for concern to human health and the environment. Hence, it is worth designing new efficient and robust sensing platforms for NB. In this study, we present three newly synthesized luminescent silver cluster‐based coordination polymers, {[Ag10(StBu)6(CF3COO)4(hpbt)] (DMAc)2(CH3CN)2}n (hpbt=N,N,N',N'N",N"‐hexa(pyridine‐4‐yl)benzene‐1,3,5‐triamine), [Ag12(StBu)6(CF3COO)6(bpva)3]n (bpva=9,10‐Bis(2‐(pyridin‐4‐yl)vinyl)anthracene), and {[Ag12(StBu)6(CF3COO)6(bpb)(DMAc)2(H2O)2] (DMAc)2}n (bpb=1,4‐Bis(4‐pyridyl)benzene) composed of Ag10, Ag12 and Ag12 cluster cores, respectively, connected by multidentate pyridine linkers. In addition, two new luminescent polymorphic silver(I)‐based coordination polymers, [Ag(CF3COO)(dpa)]n (dpa=9,10‐di(4‐pyridyl)anthracene) referred to as Agdpa (H) and Agdpa (R), where H and R denote hexagon‐ and rod‐like crystal shapes, respectively, have been prepared. The coordination polymers exhibit highly sensitive luminescence quenching effects to NB, attributed to the π−π stacking interactions between the polymers and NB as well as the electron‐withdrawing character of NB. [ABSTRACT FROM AUTHOR]