Search

The specific luminescence behavior of crystalline oxide particles doped with rare earth ions strongly depends on the initial composition of the host material and synthesis conditions. This issue is especially significant for non-isovalent doping in the crystal lattice. In this case, the formation of the structure is accompanied by the formation of point defects serving as charge compensators. The work is devoted to the synthesis of CaWO4:Nd3+ particles in the salt melt (modified Pechini method) and the study of structural and luminescent properties under varying synthesis conditions. It was found that temperature and duration of heat treatment in the salt melt (KCl) affected the crystal structure, the size of coherent scattering regions, luminescence intensity, and lifetime. An increase of heat treatment temperature led to a reduction of luminescence intensity and lifetime due to the formation of point defects. The optimal synthesis conditions for obtaining the highest luminescence intensity of CaWO4:Nd3+ crystalline particles in salt melt were found to be the following Т1= 600 °C; t1=2 h (the stage of polymer gel thermal treatment), Т2= 800 °C; t2=1 h (the stage of thermal treatment in KCl salt melt). As-synthesized CaWO4:Nd3+ powders contain both coarse and fine fractions. However weak particle agglomeration allowed obtaining a water dispersion with individual nanoparticles (up to 200 nm) after ultrasonic treatment. According to the obtained results, the synthesized material is characterized by high luminescence intensity and high dispersion, and promising as fluorescent thermometers and biological labels.

A series of double-doped YVO4 nanoparticles demonstrated contactless optical thermometry within the 298–573 K range using a ratiometric approach.

Low-doped LaVO4:Eu3+ powder provides accurate thermal sensing using different ratiometric strategies, charge transfer band position and bandwidth.

In the last decade much attention has been paid to the development of novel approaches in luminescence thermometry, which could allow contactless and noninvasive temperature sensing when traditional thermometers are useless. Typically, an optical thermometer exploits a distinct luminescence parameter to define temperature. However, the use of multimode sensors can significantly broaden the working range and improve the reliability of the temperature measurements. In this work, a Eu

Gd2(WO4)3 and Gd2(WO4)3:0.5% Tm3+, 10% Yb3+ nanopowders have been prepared by the Pechini method and solid-state sintering. According to X-ray diffraction results, the materials prepared by the Pechini method are more uniform in phase composition. Optimal synthesis conditions were defined: t = 900°C and τ = 1 h for Gd2(WO4)3 and t = 950°C and τ = 3 h for Gd2(WO4)3:0.5% Tm3+, 10% Yb3+. The surface morphology of the materials has been studied by scanning electron microscopy. The samples prepared by solid-state sintering have been found to be highly agglomerated, and large agglomerates have been shown to persist even after ultrasonic processing. The average size of the doped and undoped nanoparticles prepared by the Pechini method has been determined to be 44.0 and 47.6 nm, respectively. Luminescence spectra of Gd2(WO4)3:0.5% Tm3+, 10% Yb3+ were measured and compared the intensities of the Tm3+ 1G4 → 3H6, 1G4 → 3F4, 3F1,2→3H6, and 3H4 → 3H6 radiative transitions in the materials prepared by both methods. The data obtained in this study demonstrate that the Pechini process is a preferable and promising method for the synthesis of Gd2(WO4)3 and Gd2(WO4)3:Tm3+,Yb3+ nanopowders.

Microcrystalline anti-Stokes luminophores NaY1–x–y–zYbxEryLuzF4 were obtained for the first time by hydrothermal synthesis. These compounds crystallize in the hexagonal crystal system, structural type β-NaYF4. It was found that the addition of a non-luminescent lutetium(III) ions results in up-conversion luminescence enhancement in more than 2 times upon 980 nm excitation.

Crystalline inorganic nanoparticles doped with rare earth ions are widely used in a variety of scientific and industry applications due to the unique spectroscopic properties. The temperature dependence of their luminescence parameters makes them promising candidates for self-referencing thermal sensing. Here we report single phase YVO

Single doped CaWO

The row of metallocyclic dinuclear gold(I) complexes with cyclic diphosphines, namely, P-pyridylethyl-substituted 1,5-diaza-3,7-diphosphacyclooctanes, has been obtained. Further interaction of the dinuclear gold(I) complexes with copper(I) iodide gave the first examples of hexanuclear AuI/CuI complexes containing two unusual trinuclear AuICu2I2 fragments. The structures of di- and hexanuclear complexes were confirmed by NMR spectroscopy, ESI mass spectrometry, elemental analysis, and single-crystal X-ray diffraction. All of the obtained complexes are moderate emitters in the solid state. Dinuclear gold(I) complexes displayed a greenish emission with the maxima in the emission spectra at ca. 550 nm. The obtained hexanuclear heterobimetallic AuI/CuI complexes are triplet solid-state blue emitters with the maximum in the emission spectra at 463 and 484 nm. According to the TD-DFT calculations, the observed emission of all studied complexes had a triplet origin and was caused by the 3CC or 3(MLCT) T1 → S0 transitions for dinuclear and hexanuclear complexes, respectively.

This work demonstrates the luminescent properties of Ba3Lu2B6O15 phosphors doped with Eu3+ ions for the first time. The Ba3(Lu1–xEux)2B6O15 (x = 0.01–0.375) phosphors have been prepared using a multi-step high-temperature solid-state synthesis. X-ray diffraction measurements verify the successful isomorphic substitution of the Lu3+ sites by the Eu3+ ions. The luminescence properties and its dependence on the crystal structure of Ba3(Lu1–xEux)2B6O15 have been reported in this work. There are two nonequivalent sites in this crystal structures occupied by lutetium, both of them can be consistently substituted by the Eu3+ ions. The highest emission intensity with quantum yield of 17% was demonstrated by Ba3(Lu0.82Eu0.18)2B6O15 powder. Increase of Eu3+ doping concentration leads to gradual change of chromaticity from violet to red. It was expected that Ba3(Lu1–xEux)2B6O15 phosphors can be used as a phosphor with predicted chromaticity under LED excitation.

Contactless optical thermometry is successfully applied for accurate local temperature sensing in many scientific and technological areas. The majority of optical thermometers utilize a ratiometric...

The series of luminescent NaYF4:Sm3+ nano- and microcrystalline materials co-doped by La3+, Gd3+, and Lu3+ ions were synthesized by hydrothermal method using rare earth chlorides as the precursors and citric acid as a stabilizing agent. The phase composition of synthesized compounds was studied by PXRD. All synthesized materials except ones with high La3+ content (where LaF3 is formed) have a β-NaYF4 crystalline phase. SEM images demonstrate that all particles have shape of hexagonal prisms. The type and content of doping REE significantly effect on the particle size. Upon 400 nm excitation, phosphors exhibit distinct emission peaks in visible part of the spectrum attributed to 4G5/2→6HJ transitions (J = 5/2–11/2) of Sm3+ ion. Increasing the samarium (III) content results in concentration quenching by dipole–dipole interactions, the optimum Sm3+concentration is found to be of 2%. Co-doping by non-luminescent La3+, Gd3+ and Lu3+ ions leads to an increase in emission intensity. This effect was explained from the Sm3+ local symmetry point of view.

In this study, ZnTe crystal was applied to provide precise thermal sensing for cryogenic temperatures. Multiple techniques, namely Raman and photoluminescence spectroscopies, were used to broaden the operating temperature range and improve the reliability of the proposed thermometers. Raman-based temperature sensing could be applied in the range of 20–100 K, while luminescence-based thermometry could be utilized in a narrower range of 20–70 K. However, the latter strategy provides better relative thermal sensitivity and temperature resolution. The best thermal performances based on a single temperature-dependent parameter attain Sr = 3.82% K−1 and ΔT = 0.12 K at T = 50 K. The synergy between multiple linear regression and multiparametric thermal sensing demonstrated for Raman-based thermometry results in a ten-fold improvement of Sr and a two-fold enhancement of ΔT. All studies performed testify that the ZnTe crystal is a promising multimode contactless optical sensor for cryogenic thermometry.

An in situ microsynthesis of polyaniline films directly on a substrate was developed and considered from the viewpoint of conductivity as a key functional property. The microsynthesis was carried out in a reaction volume of 60 μL. The multi-analytical study of polyaniline samples obtained by in situ microsynthesis was performed. The effect of synthesis parameters (reaction time, temperature, and number of synthetic procedures on the same substrate) on the structure, morphology and conductivity was investigated. It was shown that the in situ microsynthesis allows for the formation of polyaniline films in the whole range of synthesis parameters chosen. The correlations between synthetic conditions, structural parameters and conductivity are discussed. The found correlations between FTIR parameters and conductivity can be considered as a promising tool for PANI characterization.

β-NaYF4:Eu3+ microparticles co-doped with Gd3+ ions were obtained by hydrothermal synthesis at 180 °C using citric acid as a stabilizing agent. All synthesized materials have a β-NaYF4 crystalline phase, where the unit cell volume increases upon the addition of Eu3+ and Gd3+ ions. The particles have a hexagonal prism shape and a size of 40–714 nm, where Eu3+ and Gd3+ doping results in size reduction. Upon 393 nm excitation, phosphors exhibit distinct emission peaks centered at 591, 615, and 695 nm and a weak band at 650 nm attributed to 5D0–7FJ transitions (J = 1–4). The optimum Eu3+ doping concentration was found to be 30% in the NaYF4 host. Concentration quenching was realized through dipole–dipole interactions. Kinetic measurements showed a gradual decline of the 5D0 lifetime from 6.7 ms to 2.2 ms along with an increase in Eu3+ doping concentration. Co-doping of the small Gd3+ number led to an increase of emission intensity and 5D0 lifetime. The effects of Eu3+ doping and Gd3+ co-doping on radiative and nonradiative decay rates were studied using 4f–4f intensity theory.

Two luminescent Cu4I4-cubane tetramers with N-methyl-10-(p-halogenophenyl)-5,10-dihydrophenarsazine ligands were synthesized and characterized by NMR spectroscopy, mass spectrometry, elemental analysis, and single-crystal X-ray diffraction analysis. The UV–Vis absorption and emission properties were studied and rationalized by DFT and time-dependent DFT calculations. The luminescence behavior was found to be rather different from that of recently reported tetranuclear copper iodide cubane clusters based on As,O-analogues – 10-(aryl)phenoxarsines. The crystalline powders of both complexes exhibit the temperature-dependent dual-band emission: the low-energy emission originates from the cluster-centered (3CC) triplet state, whereas the high-energy emission was attributed to the intraligand (3IL) triplet state.

The effect of laser activation on butyrylcholinesterase inhibition by a series of phosphorylated arylaminomalonates with different substituents in the phenyl ring is demonstrated.

Optical materials doped with several lanthanides are unique in their properties and are widely used in various fields of science and technology. The study of these systems provides solutions for noncontact thermometry, bioimaging, sensing technology, and others. In this paper, we report on the demonstration of YVO

New calix[4]resorcinols with four anthracene-ended triazolecontaining fragments as rctt- and rccc-diastereoisomers were obtained in two synthetic pathways, namely, by acidcatalyzed condensation of resorcinols with 4-{[1-(anthracen-9-ylmethyl)-1H-[1,2,3]triazol-4-yl]methoxy}benzaldehyde or by the click reaction of 9-(azidomethyl)anthracene with calix[4]resorcinols bearing four terminal acetylene moieties. The compounds obtained demonstrate dual emission in solid state with intensity of low energy band depending on calix[4]resorcinol conformation. The emission in solutions is dominated by anthracene bands, with rccc-isomer showing additional low energy band.

A number of new solid solutions Ca3 − 1.5xErx□0.5xB2SiO8 (x = 0–0.4) based on borosilicate Ca3B2SiO8 are synthesized: homogeneous solid solutions with х = 0–0.125 are structurally similar to the low-temperature monoclinic polymorphic modification of β-Сa3B2SiO8; and at 0.16 < х < 0.25, to the high-temperature orthorhombic polymorph α-Сa3B2SiO8. High-temperature X-ray powder diffraction and high-temperature Raman spectroscopy (20–1000°C) are used to study the monoclinic-orthorhombic transition of solid solutions through the two-phase region (0.125 < х

The development of new contactless thermal nanosensors based on a ratiometric approach is of significant interest. To overcome the intrinsic limitations of thermally coupled levels, a dual activation strategy was applied. Dual activation was performed using co-doped single nanoparticles and a binary mixture of single-doped nanoparticles. Co-doped and mixed YVO4:Nd3+/Eu3+ nanoparticles were successfully demonstrated as luminescent nanothermometers and their thermometric performance, in terms of thermal sensitivity, temperature resolution and repeatability, was studied and compared.

A family of helical dinuclear copper(I) pyridylphospholane complexes [Cu2L3X]X (X = BF4−, Cl− and Br−) was prepared. The family includes the first examples of this type of complex based on copper(I) chloride and copper(I) bromide. The two isomers typical of this class of compounds, namely head-to-head and head-to-tail complexes, were studied in solution by spectroscopic and optical methods, and in the solid state by X-ray diffraction. Furthermore, the solid-state luminescence of the complexes at different temperatures was studied, and the results were interpreted using quantum-chemical calculations. It was shown that the luminescence of the complexes is attributed to the 3(M + X)LCT transitions.

Accurate thermal sensing with good spatial resolution is currently required in a variety of scientific and technological areas. Luminescence nanothermometry has shown competitive superiority in contactless temperature sensing, especially at the nanoscale. To broaden the use of such thermometers, development of a novel sensor type with high sensitivity and resolution is highly demanded. Herein, we report single-phase Ln3+-doped YVO4 nanophosphors synthesized using a modified Pechini method as multimode optical thermometers for wide-range temperature probing (299–466 K). The observed temperature-induced red shift of the charge transfer band was utilized to provide thermal sensing. Temperature sensing was based on the luminescence intensity ratio using emission intensities obtained upon charge transfer and direct lanthanide excitation, the spectral position of the charge transfer band and its bandwidth. The suggested probing strategies provided a high relative thermal sensitivity (up to 3.09% K−1) and a precise temperature resolution (up to 0.1 K). The obtained results can be useful for the design of novel contactless luminescence thermometers.

YVO4:Eu3+ ceramic is an excellent crystalline phosphor, which emits at wavelength λ = 580–740 nm. The study of ceramics with Li+ doping is interesting in terms of improving the optical and strength characteristics. Obtaining Li-doped YVO4:Eu3+ was carried out by hot uniaxial pressing. Qualitative analysis of the samples revealed an increase in the grain size of the structure from 5 to 7 µm. The invariance of the phase composition was revealed by x-ray phase analysis. Intensity increase of 1.8 times was observed for YVO4:Eu3+ with Li+ compared to the sample without Li-ion by luminescence analysis. The luminescence kinetics of YVO4:Eu3+ with and without Li+ remains unchanged. The strength characteristics are increased by adding Li+ to the host matrix.

Silver molecular clusters were synthesized in photo-thermo-refractive glasses using the Na+–Ag+ ion exchange technique followed by heat treatment. Comprehensive study of cluster emission reveals the presence of spectrally separated fluorescence and phosphorescence with nanosecond and microsecond lifetime. Co-doping of glasses with Eu3+ was shown to results in quenching of cluster luminescence caused by energy transfer. The monitoring of silver cluster luminescence quantum yield and lifetime in the presence of Eu3+ indicates the presence of two different mechanisms of energy transfer. The first one affects the decay kinetics of cluster fluorescence and manifests at long distances, while the second one leads to static quenching of cluster emission at shorter distances and becomes prominent at higher doping Eu3+ concentration.

Accurate contactless thermometry is required in many rapidly developing modern applications such as biomedicine, micro- and nanoelectronics, and integrated optics. Ratiometric luminescence thermal sensing attracts a lot of attention due to its robustness toward systematic errors. Herein, a phonon-assisted upconversion in LuVO

Tertiary diethylpyridylphosphine was synthesized by the reaction of pyridylphosphine with bromoethane in a suberbasic medium. The reaction of phosphine with the copper(I) iodide led to the formation of a copper(I) coordination polymer, which, according to the X-ray diffraction data, has an intermediate structure with a copper-halide core between the octahedral and stairstep geometries of the Cu4I4 clusters. The obtained coordination polymer exhibits a green emission in the solid state, which is caused by the 3(M+X)LCT transitions. The heating up of the copper(I) coordination polymer to 138.5 °C results in its monomerization and the formation of a new solid-state phase. The new phase exhibits a red emission, with the emission band maximum at 725 nm. According to the experimental data and quantum chemical computations, it was concluded that depolymerization probably leads to a complex that is formed with the octahedral structure of the copper-halide core. The resulting solid-state phase can be backward-converted to the polymer phase via recrystallization from the acetone or DMF. Therefore, the obtained coordination polymer can be considered a sensor or detector for the overheating of processes that should be maintained at temperatures below 138 °C (e.g., engines, boiling liquids, solar heat systems, etc.).

We present an efficient and easily implemented approach for creating stable electrocatalytically active nanocomposites based on polyaniline (PANI) with metal NPs. The approach combines in situ synthesis of polyaniline followed by laser-induced deposition (LID) of Ag, Pt, and AgPt NPs. The observed peculiarity of LID of PANI is the role of the substrate during the formation of multi-metallic nanoparticles (MNP). This allows us to solve the problem of losing catalytically active particles from the electrode’s surface in electrochemical use. The synthesized PANI/Ag, PANI/Pt, and PANI/AgPt composites were studied with different techniques, such as SEM, EDX, Raman spectroscopy, and XPS. These suggested a mechanism for the formation of MNP on PANI. The MNP–PANI interaction was demonstrated, and the functionality of the nanocomposites was studied through the electrocatalysis of the hydrogen evolution reaction. The PANI/AgPt nanocomposites demonstrated both the best activity and the most stable metal component in this process. The suggested approach can be considered as universal, since it can be extended to the creation of electrocatalytically active nanocomposites with various mono- and multi-metallic NPs.

Doping the semiconductor nanocrystals is one of the most effective ways to obtain unique materials suitable for high-performance next-generation optoelectronic devices. In this study, we demonstrate a novel nanomaterial for the near-infrared spectral region. To do this, we developed a partial cation exchange reaction on the HgTe nanoplatelets, substituting Hg cations with Pb cations. Under the optimized reaction conditions and Pb precursor ratio, a photoluminescence band shifts to ~1100 nm with a quantum yield of 22%. Based on steady-state and transient optical spectroscopies, we suggest a model of photoexcitation relaxation in the HgTe:Pb nanoplatelets. We also demonstrate that the thin films of doped nanoplatelets possess superior electric properties compared to their pristine counterparts. These findings show that Pb-doped HgTe nanoplatelets are new perspective material for application in both light-emitting and light-detection devices operating in the near-infrared spectral region.

Single doped CaWO4:Er3+ phosphors were synthesized and studied for application of optical thermal sensing within a wide range of 98–773 K. Ratiometric strategy utilizing two luminescence intensity ratios, one between host and Er3+ band (LIR1) and second between different Er3+ transitions (LIR2), results in self-referencing temperature readouts. The presence of two temperature-dependent parameters could improve thermometric characteristics and broaden the working temperature range compared to a usual single-parameter thermometer. Thermometric performances of prepared samples were evaluated in terms of thermal sensitivities, temperature resolution and repeatability. The highest sensitivity of 2.09% K−1@300 K was found for LIR1, whereas LIR2 provided more accurate thermal sensing with a temperature resolution of 0.06–0.1 K. Effect of Er3+ doping concentration on sensing properties were studied. The presented findings indicate that CaWO4:Er3+ phosphors are perspective in dual-mode thermal sensing with high sensitivity and sub-degree resolution.

During last decade luminescence thermometry has become a widely studied research field due to its potential applications for real time contactless temperature sensing where usual thermometers cannot be used. Special attention is paid to the development of accurate and reliable thermal sensors with simple reading. To address existing problems of ratiometric thermometers based on thermally-coupled levels, LuVO

Two luminescent Cu

The luminescent coarse-, micro- and nanocrystalline europium(III) terephthalate tetrahydrate (Eu2bdc3·4H2O) metal-organic frameworks were synthesized by the ultrasound-assisted wet-chemical method. Electron micrographs show that the europium(III) terephthalate microparticles are 7 μm long leaf-like plates. According to the dynamic light scattering technique, the average size of the Eu2bdc3·4H2O nanoparticles is equal to about 8 ± 2 nm. Thereby, the reported Eu2bdc3·4H2O nanoparticles are the smallest nanosized rare-earth-based MOF crystals, to the best of our knowledge. The synthesized materials demonstrate red emission due to the 5D0–7FJ transitions of Eu3+ upon 250 nm excitation into 1ππ* state of the terephthalate ion. Size reduction results in broadened emission bands, an increase in the non-radiative rate constants and a decrease in both the quantum efficiency of the 5D0 level and Eu3+ and the luminescence quantum yields. Cu2+, Cr3+, and Fe3+ ions efficiently and selectively quench the luminescence of nanocrystalline europium(III) terephthalate, which makes it a prospective material for luminescent probes to monitor these ions in waste and drinking water.

For the first time, the 3(X + M)LCT origin of both the lowest excited triplet states of dual-emissive tetranuclear copper(I)-iodide complexes with the octahedral Cu4I4 core has been revealed using quantum chemical computations in contrast to the conventional assignment of the lowest-energy emission to the 3CC state. The unusual thermochromic behavior shown for dual emission from these states of Cu4I4 clusters stabilized by P,N-ligands allows optical ratiometric thermal sensing in a broad temperature range.

Eu3+-doped MgAl2O4 nanoparticles were prepared by modified Pechini method. X-ray diffraction analysis shows pure tetragonal spinel phase without any impurities. The average size of synthesized nanoparticles was determined to be about 50–60 nm using scanning electron microscopy and static light scattering techniques. Emission and excitation spectra as well as lifetimes of MgAl2O4:Eu3+ nanophosphors were explored in surrounding media with different refractive indexes. Surrounding medium does not affect luminescence bands position, whereas 5D0 lifetime monotonically decreases along with increase of medium refractive index. Effect of surrounding media on radiative and nonradiative decay rates, which were calculated using 4f–4f intensity theory, was studied and discussed. Filling factor of prepared nanoparticles is defined using both radiative and observed lifetimes.

A series of novel charged disilver(I) complexes with pyridyl-containing phospholanes was synthesized. These complexes were characterized using a range of spectroscopic techniques and single-crystal and powder X-ray diffraction. The complexes demonstrate solid-state near-infrared (NIR) luminescence (765-902 nm) that is unique for dinuclear AgI complexes. Combined spectroscopic/quantum chemical analysis suggests that the NIR luminescence of complexes 4-6 in the solid state is mainly due to crystal packing effects.

The complex cis-[PtCl2(Me2SO)2] (1) reacts with 1 equiv. of C-4-trifluoromethylphenyl-N-methylaminonitrone (2) to give the product [PtCl(Me2SO){ O N(Me)C(4-CF3C6H4) N H}] (3; 75%). Treatment of 3 with an excess cyclohexyl isocyanide, CyNC, leads to the acyclic diaminocarbene complex [PtCl(CNCy){ N (Me)C(4-CF3C6H4)N C (=NHCy)}] (4; 28%). The latter exhibits solid-state phosphorescence with an emission maximum at 600 nm and 23% quantum yield. Complexes 3 and 4 were characterized by HRESI+-MS, FTIR, 1H and 13C{1H} NMR spectroscopic techniques. The complex 4 was additionally characterized by X-ray diffraction; short Pt Pt contacts (3.2360(5) A) were observed in the crystal structure. These non-covalent interactions have an attractive nature and their estimated strength is 4.6–5.6 kcal/mol.

The contactless real-time temperature sensing technique with high temporal and spatial resolution is in high demand for the countless applications. Here, the Yb3+/Er3+−codoped GeO2–PbO–PbF2 glass ceramics synthesized via the melt-quenching technique has been presented as an optical thermometer. The thermal sensing was designed based on the temperature dependent fluorescence intensity ratios of thermally (2H11/2 and 4S3/2) and non-thermally (2H11/2 and 4F9/2) coupled Er3+ levels. The ratiometric techniques provide the thermal sensing within the temperature range of 300–466 K. The absolute and relative thermal sensitivities as well as the temperature resolution were calculated and compared with other Yb3+/Er3+-doped materials. The temperature of the microelectronic component on the printed circuit board was defined using the optical thermometry as a proof of concept revealing Yb3+/Er3+−codoped GeO2–PbO–PbF2 phosphor to be a promising candidate for precise non-contact thermal sensor.

Using Suzuki and Yamamoto coupling reactions, copoly-(9,9-dioctylfluorenes) (CPF) were synthesized and compared regarding their photophysical properties using the spectroscopic and ab initio DFT approaches. The CPFs were functionalized by benzo [2,3,5] thiadiazole (BT) or carbazole-3,6-diyl (3,6-Cz). The latter was used to introduce different luminophore fragments, including Nile red and 4-pyrrolidinyl-1,8-naphthalimide derivatives. The effect of the two synthesis techniques on the polymer microstructure, the influence of embedding of 3,6-Cz moieties in the polymer backbone on polymer structuring, and the impact of the end groups like novel quinoxaline-containing compounds on the luminescent properties of CPFs were investigated. By comparing electron density distribution using the ab initio DFT approach with photoluminescence, it was shown that Suzuki reaction provides a chain microstructure with individual BT fragments separated by 9,9-dioctylfluorene monomeric units, while Yamamoto reaction leads to the blocks of BT units. This effect leads to different CPF photophysical properties (absorption and emission spectra).

A novel single-step, laser-induced and solution-based process is presented for synthesizing complex hybrid metal/carbon nanostructures. The process relies on simply illuminating the interface between a substrate and a liquid solution of the supramolecular complex [Au13Ag12(C2Ph)20(PPh2(C6H4)3PPh2)3][PF6]5 (hereinafter abbreviated as SMC) with an unfocussed He–Cd laser having a wavelength of 325 nm and an intensity of I = 0.5 W/cm2. The process results in hybrid nanostructures of well-controlled morphology: nanoparticles (NP) and 2D flakes, which may also grow jointly to form 3D morphologically complex multipetal ‘flower-like’ structures. At the atomic scale, the obtained metamaterials are complex in composition and structure, i.e., they contain bimetallic Au–Ag nanoclusters of diameter 3–5 nm incorporated inside a carbonaceous matrix. This matrix can be amorphous or crystalline, and the details of the compositional outcome can be controlled and steered by the laser deposition parameters. Au–Ag nanoclusters show plasmonic behavior including the enhancement of electromagnetic fields of visible light. This leads to the enhancement of Raman scattering by the Au–Ag nanoparticle ensemble within the carbonaceous matrix. This enables a 3D architecture for stimulating surface-enhanced Raman scattering (SERS).

Development of new approaches to the noncontact optical thermometry is of great importance for modern science and technology. In the current work, single-phase YVO4:Eu3+ nanoparticles prepared via ...

Single molecule luminophores capable of multiple emissions are essential for the development of new materials with unconventional photophysical behavior. In this work, a family of diphosphine ligands PPh2–PAH–PPh2 with variable polyaromatic hydrocarbon (PAH) spacers (PAH = 9,10-anthracene L1, 1,4-naphthalene L2, 2,6-naphthalene L3, and their diethynyl congeners L4–L6) were employed to prepare gold(I) complexes (RC2Au)PPh2–PAH–PPh2(AuC2R) (1–22), containing a selection of alkynyl groups. Investigation of their optical properties indicates that compounds with anthracene-based diphosphines (1–4 and 13–16) display only 1IL (ππ*) fluorescence with Φem up to 93%. The naphthalene and diethynyl-naphthalene diphosphine complexes (5–12 and 17–22), however, demonstrate panchromatic emission in the solid state and in solution featuring well-separated low and high energy signals, which originate from 1IL (ππ*) and 3IL (ππ*) transitions along with certain contribution from metal to ligand and ligand to ligand charge transfers.