Correction: Photoluminescence modification of europium(III)-doped MAlO (M = Zn, Mg) spinels induced by Ag@SiO core-shell nanoparticles.

Correction for 'Photoluminescence modification of europium(III)-doped MAlO (M = Zn, Mg) spinels induced by Ag@SiO core-shell nanoparticles' by Rodrigo A. Valenzuela-Fernández , , 2024, https://doi.org/10.

Synthesis and Optical Properties of a Novel Hybrid Nanosystem Based on Covalently Modified nSiO Nanoparticles with a Curcuminoid Molecule.

A new curcuminoid molecule () has been designed and synthesized, containing a central -(CH)-COOH chain at the α carbon of the keto-enol moiety in the structure. The carboxylic acid group is added to react with exposed amino groups on silica oxide nanoparticles (nSiO), forming an amide bond to attach the curcuminoid moiety to the nSiO covalently. The Kaiser test quantifies the functionalization degree, yielding 222 μmol of curcuminoid per gram of nanoparticles.

Photoluminescence modification of europium(III)-doped MAlO (M = Zn, Mg) spinels induced by Ag@SiO core-shell nanoparticles.

In recent years, there has been an increasing interest in developing new inorganic compounds with exceptional properties for advanced materials. Specifically, compounds containing europium have attracted much attention due to their luminescent properties. These compounds are used in electronics, biotechnology, medicine, and catalysis.

Photoinduced behaviour of N,N-bidentate manganese(I) and rhenium(I) tricarbonyl complexes for singlet oxygen generation and CO release.

The combined action of singlet oxygen (O) and photoinduced carbon monoxide (CO) released by tricarbonyl metal complexes is a promising synergic treatment against multi-resistant bacterial infections. In this work, we explore the use of a polydentate ligand (bpm = 2,2-bipyrimidine) that offers the opportunity to accommodate two metal centers exhibiting both singlet oxygen generation and carbon monoxide releasing properties in a single molecule. A series of monometallic ([(bpm)M(CO)Br]; M = Mn, Re) and homo or hetero bimetallic ([Br(CO)M(bpm)M'(CO)Br]; M = Mn, Re) compounds were synthesized in moderate to good yields by modulating the metal precursor or the stoichiometry, also the syn:anti isomers ratio for the bimetallic complexes was dependent on the experimental conditions used.

Synthesis of fluorescent chalcones, photophysical properties, quantitative structure-activity relationship and their biological application.

The development of fluorescent pigments is an area of interest in several research fields due to their high sensitivity. In the current study-eight known and three new N,N-dimethylamino-chalcones (12a-k) were synthesized with good yields using the Claisen-Schmidt reaction. For each molecular system, the photophysical properties, including the maximum absorption wavelength (λ), molar absorption coefficient (ε), maximum excitation wavelength (λ), maximum emission wavelength (λ), Stokes Shift (Δλ), fluorescence quantum yield (Φ), fluorescence lifetime (τ), radiative and non-radiative rate constants (k and k, respectively) were evaluated.

New Light-Green Thermally Activated Delayed Fluorescence Polymer Based on Dimethylacridine-Triphenyltriazine Light-Emitting Unit and Tetraphenylsilane Moiety as Non-Conjugated Backbone.

In the search for solution-processable TADF materials as a light emitting layer for OLED devices, polymers have attracted considerable attention due to their better thermal and morphological properties in the film state with respect to small molecules. In this work, a new polymer (-TPS-DMAC-TRZ) with thermally activated delayed fluorescence (TADF) light-emitting characteristics was prepared from a conjugation-break unit (TPS) and a well-known TADF core (DAMC-TRZ). This material was designed to preserve the photophysical properties of DAMC-TRZ, while improving other properties, such as thermal stability, promoted by its polymerization with a TPS core.

Photochemistry of P,N-bidentate rhenium(i) tricarbonyl complexes: reactive species generation and potential application for antibacterial photodynamic therapy.

In this work, we describe the photoisomerization of facial rhenium(i) tricarbonyl complexes bearing P,N-bidentate pyridyl/phosphine ligands with different chelating rings and anions: RePNBr, RePNTfO, and RePNNBr, which are triggered under irradiation at 365 nm in solutions. The apparent photodegradation rate constants ( ) depend on the coordinating ability of the solvent, being lowest in acetonitrile. The value increases as the temperature rises, suggesting a reactive IL excited state thermally populated from the MLCT excited state involved.

Spectroscopic Study of the E/Z Photoisomerization of a New Cyrhetrenyl Acylhydrazone: A Potential Photoswitch and Photosensitizer.

The new cyrhetrenyl acylhydrazone [(CO) Re(η -C H )-C(O)-NH-N = C(CH )-(2-C H S-5-NO )] (E-CyAH) has been designed, synthesized and fully characterized to study the effect of having a cyrhetrenyl fragment (sensitizer) covalently bonded to an acylhydrazone moiety (switch), on its photophysical and photochemical properties. The crystal structure reveals that E-CyAH adopts an E-configuration around the iminic moiety [-N = C(CH )]. The absorption spectrum of E-CyAH displays two bands at 270 and 380 nm, which are mainly ascribed to π → π* intraligand (IL) and d  → π* metal-to-ligand charge transfer (MLCT) transitions, being consistent with DFT/TD-DFT calculations.

Fatty Acid Conjugates of Toluidine Blue O as Amphiphilic Photosensitizers: Synthesis, Solubility, Photophysics and Photochemical Properties.

Toluidine blue O (TBO) is a water-soluble photosensitizer that has been used in photodynamic antimicrobial and anticancer treatments, but suffers from limited solubility in hydrophobic media. In an effort to incrementally increase TBO's hydrophobicity, we describe the synthesis of hexanoic (TBOC6) and myristic (TBOC14) fatty acid derivatives of TBO formed in low to moderate percent yields by condensation with the free amine site. Covalently linking 6 and 14 carbon chains led to modifications of not only TBO's solubility, but also its photophysical and photochemical properties.

The Effect of Pyrazolyl Substituents on the Photophysical and Photochemical Properties of Pyrazine Derivatives.

The reaction of 2,5-dibromopyrazine with N-Lithium pyrazolate in a 1:2 ratio leads to a mixture of 2-bromo-5-(1H-pyrazol-1-yl)pyrazine (I) and 2,5-di(1H-pyrazol-1-yl)pyrazine (II). The structures of I and II are highly planar. Two absorption bands can be observed for the compounds in the UV-Vis region, having ε in the order of 10  m  cm .

The first Re organometallic complex with an organoimido-polyoxometalate ligand.

The spectroscopic, electrochemical and photophysical properties of the first Re organometallic organoimido-polyoxometalate complex [n-BuN][MoONCH-CH-NCH-Re-phen(CO)] compared with all fragments are reported. The UV-Vis spectra are analysed using experimental and theoretical tools. In contrast to the reported studies in the literature, our results show that a new more intense band is present in the spectra of the hybrid ligand obscuring the intra-polyanion charge transfer.

Fluorescence properties of aurone derivatives: an experimental and theoretical study with some preliminary biological applications.

In this paper, we explored the fluorescence properties of eight aurone derivatives bearing methoxy groups and bromine atoms as substituents in the benzene rings. All derivatives showed strong solvatochromic absorption and emission properties in solvents of different polarities. Some of them showed high fluorescence quantum yields, which make them potential compounds for sensing applications.

The binuclear dual emitter [Br(CO)Re(PN)(NP)Re(CO)Br] (PN): 3-chloro-6-(4-diphenylphosphinyl)butoxypyridazine, a new bridging P,N-bidentate ligand resulting from the ring opening of tetrahydrofuran.

Lithium diphenylphosphide unexpectedly provokes the ring-opening of tetrahydrofuran (THF) and by reaction with 3,6-dichloropyridazine leads to the formation of the ligand 3-chloro-6-(4-diphenylphosphinyl)butoxypyridazine (P⋯N), which was isolated. The reaction of this ligand with the (Re(CO)(THF)Br) dimer yields the novel complex [Br(CO)Re(μ-3-chloro-6-(4-diphenylphosphinyl)butoxypyridazine)Re(CO)Br] (BrRe(P⋯N)(N⋯P)ReBr), which was crystallized in the form of a chloroform solvate, (CHBrClNOPRe)·(CHCl). The monoclinic crystal (P2/n) displays a bimetallic cage structure with a symmetry inversion centre in the middle of the rhenium to rhenium line.

Flavonoids in Microheterogeneous Media, Relationship between Their Relative Location and Their Reactivity towards Singlet Oxygen.

In this work, the relationship between the molecular structure of three flavonoids (kaempferol, quercetin and morin), their relative location in microheterogeneous media (liposomes and erythrocyte membranes) and their reactivity against singlet oxygen was studied. The changes observed in membrane fluidity induced by the presence of these flavonoids and the influence of their lipophilicity/hydrophilicity on the antioxidant activity in lipid membranes were evaluated by means of fluorescent probes such as Laurdan and diphenylhexatriene (DPH). The small differences observed for the value of generalized polarization of Laurdan (GP) curves in function of the concentration of flavonoids, indicate that these three compounds promote similar alterations in liposomes and erythrocyte membranes.

Dual Emission of a Novel (P,N) Re(I) Complex: A Computational and Experimental Study on [P,N-{(C6H5)2(C5H4N)P}Re(CO)3Br].

The spectroscopic, electrochemical, and photophysical properties of the new complex [P,N-{(C6H5)2(C5H4N)P}Re(CO)3Br] are reported. The UV-vis spectrum in dichloromethane shows an absorption maximum centered at 315 nm and a shoulder at 350 nm. These absorption bands have been characterized to have MLCT character.

Substituent Effect on the Photolability of 4-Aryl-1,4-Dihydropyridines.

The electronic nature of substituents attached to the 4-aryl moiety of 1,4-dihydropyridines strongly affects the photophysical and photochemical behavior of these family of compounds. The presence of an electron donor substituent on the 4-aryl moiety (or the absence of electron-withdrawing ones) modifies the luminescence lifetimes (τ < 100 ps) and diminishes the photodecomposition quantum yields. For electron-withdrawing substituents, the photodegradation quantum yield is affected by the media, changing more than two orders of magnitude as the polarity is increased.

Solvent and media effects on the photophysics of naphthoxazole derivatives.

The photophysical properties of 2-phenyl-naphtho[1,2-d][1,3]oxazole, 2(4-N,N-dimethylaminophenyl)naphtho[1,2-d][1,3]oxazole and 2(4-N,N-diphenylaminophenyl) naphtho[1,2-d][1,3]oxazole were studied in a series of solvents. UV-Vis absorption spectra are insensitive to solvent polarity whereas the fluorescence spectra in the same solvent set show an important solvatochromic effect leading to large Stokes shifts. Linear solvation energy relationships were employed to correlate the position of fluorescence spectra maxima with microscopic empirical solvent parameters.

Photophysics and photochemistry of naphthoxazinone derivatives.

The photophysics and photochemistry of a series of naphthoxazinones have been studied using a combination of methods ranging from steady-state and time-resolved spectroscopic techniques to product analysis. The photophysics of naphthoxazinone derivatives is very dependent on the structure: phenanthrene-like compounds exhibit higher fluorescence quantum yield than the less aromatic anthracene-like homologous. The latter, exhibit a substantial degree of charge transfer in the excited singlet state.

Solvent effect on the sensitized photooxygenation of 2,3-dihydropyrazine derivatives.

Detection of O(2)((1)Delta(g)) phosphorescence emission, lambda(max) = 1270 nm, following laser excitation and steady-state methods was employed to determine the total rate constant, k(T), and the chemical reaction rate constant, k(R), for reaction between 5,6-disubstituted-2,3-dihydropyrazines and singlet oxygen in several solvents. Values of k(T) ranged from 0.26 x 10(5) M(-1) s(-1) in hexafluoro-2-propanol to 58.