In this study, zinc phthalocyanines (ZnPcs) substituted with tetracarboxy groups were synthesized and characterized using UV - VIS spectroscopy, fluorescence spectroscopy, NMR, and mass spectrometry. The photophysical properties depend on the peripheral substituents and the presence of noble metal nanoparticles. The UV - VIS spectra of ZnPcs 15 - 19 showed Soret bands at 348 - 352 nm and Q bands at 615 - 683 nm, typical of nanostructured phthalocyanines. The emission spectra, upon excitation at 616 nm, displayed two main bands at 688 - 692 nm and 757 - 759 nm, assigned to the Q(x)(0 - 0) and Q(x)(0 - 1) transitions. The fluorescence quantum yields (ΦF) varied significantly: ZnPc 16 exhibited the highest ΦF, while ZnPc 19 showed reduced values in the increased presence of AgNPs. Samples 16 - 18 presented higher yields than the reference sample. Fluorescence lifetimes indicated energy transfer to the triplet state for some compounds. The solvent effect study revealed a decrease in fluorescence intensity with increasing water content in DMSO, suggesting aggregation and quenching. The results demonstrate the influence of peripheral substitution and the surrounding medium on the photophysical behavior of zinc phthalocyanines.

The article presents the results of the study of zinc phthalocyanine and zinc tetracarboxyphthalocyanine as ionophores of polymer matrix electrodes sensitive to the presence of zinc ions. Based on these compounds, two ion-selective electrodes were assembled: EIS1 and EIS2. The electrodes exhibit a cationic function in compliance with the Nernst function in the concentration range 102 - 10-5 mol/L, with a response time of 10 - 20 seconds. The potentiometric selectivity constants indicate a more pronounced interference on the potentiometric measurements from aluminum ions. The sensors were tested as indicator electrodes in potentiometric titrations of model samples containing Zn2+ ions, and the results obtained indicate the possibility of using them to determine the equivalence point with good accuracy.

This study reports the synthesis, structural characterization, and chemical analysis of pure NaMgF3 and CeO2-doped NaMgF3 perovskite materials. The compounds were prepared via a combined co-precipitation and solid-state reaction approach, ensuring homogeneous incorporation of cerium into the NaMgF3 lattice. X-ray diffraction XRD analysis confirmed that all samples crystallize in a single-phase orthorhombic perovskite structure (space group Pbnm) while XPS provides insights into the bonding, chemical environment, and chemical state of elements present respectively. According to XRD studies Ce incorporation inducing minor peak shifts, a slight reduction in crystallite size (from 35.7 nm to 34.7 nm), and decreased lattice strain (0.27

In this paper, the photophysical properties of thiol-functionalized zinc phthalocyanine (ZnPc(SH)8) conjugated with silver nanoparticles (AgNPs) were investigated. AgNPs were synthesized using modified citrate and tannic acid reduction methods, producing nanoparticles with distinct plasmonic features. ZnPc(SH)8 was obtained via cyclotetramerization of tetra(alkylthio)phthalonitrile in the presence of zinc acetate and subsequently conjugated to AgNPs through thiol anchoring groups. UV-Vis spectroscopy confirmed the formation of ZnPc(SH)8/AgNPs assemblies, showing characteristic ZnPc Soret and Q bands alongside AgNPs surface plasmon resonance bands. Variations in absorption intensity and band positions reflected differences in nanoparticle size, aggregation, and coupling strength. Fluorescence measurements revealed plasmon-mediated modulation of ZnPc emission, including quenching and enhancement effects depending on the AgNPs characteristics. Transient absorption spectroscopy indicated dominant ground-state bleaching and long-lived excited or charge-separated states, suggesting plasmon-molecule coupling and charge-transfer dynamics. Time-resolved fluorescence showed shortened singlet lifetimes in the presence of AgNPs, while phosphorescence measurements revealed prolonged triplet-state lifetimes, consistent with modified radiative and non-radiative decay pathways induced by plasmonic interactions. These results demonstrate that AgNPs conjugation significantly alters the photophysical behavior of ZnPc(SH)8, highlighting the potential of ZnPc(SH)8/AgNPs nanocomposites as plasmon-enhanced photosensitizers for photodynamic therapy and other photonic applications.

This study presents a comprehensive analysis of the photophysicochemical properties of zinc(ii) 2,9,16,23-tetracarboxy-phthalocyanine (TcPcZn), N,N'-bis(3-pentyl)perylene-3,4,9,10-bis(dicarboximide) (EP-PDI), and their mixed systems in various TFA/H2O solvent mixtures. Key aspects discussed include molecular arrangement, intra- and intermolecular interactions, protonation effects on absorbance and aggregation, light-induced partial deprotonation of TcPcZn, and Förster Resonance Energy Transfer (FRET) effects on excited-state lifetimes. Due to strong solvent quenching, the singlet-state lifetimes of EP-PDI (1.07 and 2.91 ns), TcPcZn (0.67 and 3.79 ns), and their TcPcZn : EP-PDI mixture (0.64 and 3.96 ns) were measurable only at high concentrations (C M ≥ 0.110 mM). Both individual compounds and their blends exhibit promising triplet-state lifetimes, which are crucial for processes relying on long-lived excited states, such as photodynamic therapy and optoelectronic applications. In this context, particular attention is given to their ability to sustain room-temperature phosphorescence (RTP) : TcPcZn - 8.93 µs, EP-PDI - 10.18 µs, and TcPcZn : EP-PDI - 9.41 µs. Several strategies are proposed to further optimize these parameters and enhance RTP quantum yields.

This paper presents a comparative study of the photophysical properties of ZnPc, ZnPc(SO₃)₄ and ZnPc(OH)₄ compounds dissolved in DMSO. The photophysical characteristics of the studied compounds were examined using UV–Vis absorption, fluorescence, and transient absorption spectroscopy. The UV–Vis spectra revealed the characteristic B/Soret and Q absorption bands of zinc phthalocyanines, with noticeable differences in band position, intensity and broadening in dependence on the peripheral substituents. Fluorescence investigations demonstrated that ZnPc possesses the highest fluorescence quantum yield (26.08%) and efficient radiative relaxation behavior, whereas ZnPc(SO₃)₄ and ZnPc(OH)₄ showed significantly lower fluorescence efficiencies due to increased non-radiative deactivation pathways. Time-resolved fluorescence measurements revealed lifetimes in the nanosecond domain for all investigated compounds. Transient absorption spectroscopy demonstrated efficient excited-state formation and the presence of long-lived triplet excited states extending up to the microsecond time region. The obtained results highlight the strong influence of peripheral functional groups on the optical absorption, fluorescence behavior, aggregation tendency, and excited-state dynamics of zinc phthalocyanines.

NaMgF3 nanoparticles were successfully synthesized via a co-precipitation method and calcined at 500-700 degrees C for different durations to investigate the influence of thermal treatment on their structural and compositional properties. XRD confirmed a stable single-phase orthorhombic NaMgF3 structure under all conditions. Increasing the calcination temperature resulted in crystallite coarsening from 34.1 to 39.8 nm, while prolonged treatment at 700 degrees C (12 h) further enhanced grain growth up to 46.7 nm, accompanied by a significant reduction in microstrain (from 0.33% to 0.25%) and dislocation density (from 0.73 to 0.52 x 10-3 nm-2), indicating defect annealing and lattice relaxation. XPS revealed temperature-dependent shifts in Na 1s, Mg 1s and F 1s binding energies, suggesting stabilization of cation coordination environments and reduction in surface defects. EDS and XPS confirmed stoichiometric composition with good agreement to the theoretical NaMgF3 ratio. These findings demonstrate that calcination plays a critical role in tuning the structural integrity, defect distribution, and chemical stability of NaMgF3 nanoparticles, which is essential for their integration in radiation detection, dielectric, and optoelectronic applications.

This study reports the synthesis, photophysical characterization, and fluorescence behavior of [octakis(chloromethyl)phthalocyaninato]zinc conjugated with gold nanoparticles (AuNPs). The compound was prepared via a chloromethylation reaction of zinc phthalocyanine, followed by conjugation with AuNPs stabilized with tannic acid or sodium citrate. UV-Vis absorption spectra revealed intense Q bands in the 580–780 nm range, with additional solvent-dependent features in the near-IR region. Steady-state fluorescence measurements showed red-shifted emission by 6–10 nm relative to the absorption maxima, with small Stokes shifts indicating minimal energy loss between absorption and emission. Fluorescence lifetimes, determined using time-correlated single-photon counting, exhibited bi-exponential behavior, reflecting two distinct molecular populations in DMSO:H₂O. Quantum yields were low, suggesting that the compounds are more suitable as diagnostic fluorescence probes than as photosensitizers for photodynamic therapy. Transient absorption spectroscopy revealed negative bands corresponding to ground-state bleach and stimulated emission, with an estimated lifetime of 12 ns, and no observable triplet state absorption. These results provide insights into the photophysical properties and non-radiative deactivation pathways of the hybrid system. The study demonstrates the potential of [octakis(chloromethyl)phthalocyaninato]zinc:AuNPs assemblies for advanced photonic and biomedical applications and highlights the importance of controlled nanoparticle functionalization to tune their emission properties.

We fabricated erbium, cerium, and their alloy oxide nanoparticles using the co-precipitation method. EDS analysis demonstrates the presence of oxygen, erbium, and cerium elements. FTIR and XRD analyses confirm the formation of Er2O3, CeO2, and their alloy nanoparticles. XRD analysis revealed that the lattice parameters of CeO(2 )nanoparticles increase with the addition of Er2O3. The photoluminescence spectrum, measured with a 532 nm green laser at room temperature, exhibited both green (540-570 nm) and red (650-700 nm) luminescence. The photoluminescence properties of Er(2)O(3 )nanoparticles originate from relaxation and emission corresponding to the S-4(3/2)-*I-4(15/2) and F-4(9/2)-*I-4(15/2) transitions, while the emission bands of CeO(2 )nanoparticles arise from oxygen vacancies forming F-centers and Ce3+-related defects such as vacancies and interstitial atoms. The photoluminescence spectrum of Er:Ce:O alloy nanoparticles exhibit two intense bands in the region from 547 nm to 560 nm, with maxima at 2.266 eV and 2.214 eV, associated with f-f internal transitions( 4)F(9/2)-*I-4(15/2) and S-4(3/2)-*I-4(15/2) in the Er3+ ion, indicating the incorporation of Er3+ ions into the crystal lattice as substitutional ions

In this paper, monosubstituted derivatives of zinc and cobalt phthalocyanines are presented, of the mono-aminomethylene type (AM-PcZn, AM-PcCo) and mono-o-carboxybenzamidomethylene (CBAMPcZn, CBAM-PcCo), obtained through thermo-mechanochemistry and characterized by FTIR, UV-Vis, and fluorescence spectroscopy. The compounds were characterized by FTIR, UV-Vis, and fluorescence spectroscopy. FTIR spectra confirm successful functionalization through the presence of -NH₂ and -CONHgroups. UV-Vis analysis reveals a strong Q-band around 670 nm, characteristic of the phthalocyanine macrocycle. Fluorescence spectra recorded at excitation with λex = 340 nm show emission in the 350-600 nm region, while at excitation with λex = 640 nm leads to intensive emission in the 800-850 nm region. AM-PcZn derivatives exhibit higher fluorescence intensity in the NIR region. Emission within the 700- 900 nm region highlights the potential of these compounds for photodynamic therapy applications.

Room-temperature phosphorescent materials are needed because they offer unique properties and potential applications in various fields due to their capacity to absorb, store and emit light. In this study we summarized the progress in long-lived room-temperature phosphorescent system synthetized by self-assembly of ZnPc(COOH)₄ derivative and ZnO/Dx NPs in DMSO/H2O through a combination of electrostatic interactions and hydrogen bonding. Conjugation of the peripheral carboxy (–COO−) substituted ZnPc to ZnO/Dx NPs in DMSO/H2O broaden absorption bands, boost its triplet quantum yields and increase their triplet lifetimes from 8.9 μs to 10.2 μs. The triplet state parameters discussed in this study, together with the ground state absorption properties suggest that ZnPc(COOH)₄/Dx/ZnO composite may be tested as photosensitizers in photodynamic therapy.

The development of phthalocyanine derivatives with enhanced photophysical properties is crucial for advancing applications in optoelectronics, photodynamic therapy (PDT), and other medical fields. In this study, we investigated the photophysical properties of two zinc phthalocyanine derivatives: mono-(o-carboxybenzamidomethylene) (mono-CBAM-PcZn) and tetra-(o-carboxybenzamidomethylene) (tetra-CBAM-PcZn), both solubilized in water to facilitate biomedical applicability. The absorption spectra of both derivatives showed characteristic Q- and Soret bands, with tetra-CBAM-PcZn displaying red-shifted absorption features at 812 nm compared to mono-CBAM-PcZn, indicating an extended π-conjugation and potential for deeper tissue penetration in PDT. Fluorescence measurements revealed a significant increase in the quantum yield fluorescence from 10.08

In this study, we report the synthesis and characterization of Fe3O4 nanoparticles coated with dextran. The structural and optical properties of the Dx:Fe3O4 synthesized composites were investigated by Fourier Transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and UV–Vis absorption spectroscopy. For the first time in this paper, the photophysics of Dx:Fe3O4 composites in water is studied using fluorescence and phosphorescence molecular spectrometry. An analysis of the absorption spectra of the Dx:Fe3O4 composite reveals the broad absorption bands with maxima at wavelengths of 227 nm, 264 nm, and 340 nm. Dx:Fe3O4 composite nanoparticles in water exhibit strong fluorescence with a quantum yield of 0.24% in contrast to 0.07% for dextran. Phosphorescence spectra confirm the formation of new emission bands within the Dx:Fe3O4 solution evidenced by the maxima shift for both dextran and Dx:Fe3O4 composites.

Magnesium oxide (MgO) nanoparticles were synthesized using two distinct stabilizing agents-sodium dodecyl sulphate (SDS) and Aloe Vera extract (AVE)-in order to evaluate how electrostatic versus biopolymeric stabilization affects nucleation, crystallite formation, and final structural properties. The nanoparticles were obtained through a precipitation route followed by calcination at 500-1100°C. XRD analysis confirmed the formation of nanocrystalline MgO, with the crystallite size being slightly influenced by the choice of stabilizing agent. SDS promoted electrostatic micellar templating, resulting in faster nucleation and smaller but defect-richer crystallites, whereas Aloe Vera acted as a steric capping agent that delayed supersaturation and enabled more ordered crystal growth. FTIR and XPS analyses revealed temperature-dependent dehydroxylation and surface carbonation effects, consistent with nanoscale MgO chemical reactivity. The optical bandgap ranged from 5.4 to 6.0 eV, exhibiting a blue shift relative to bulk MgO due to nanoscale confinement and surface defect states. Overall, the results demonstrate that the precipitation environment plays a decisive role in controlling MgO crystallization kinetics, defect chemistry, and nanoparticle stability, with Aloe Vera providing superior steric stabilization against agglomeration compared to SDS.

In this paper, dye-sensitized solar cells (DSSCs) are fabricated and studied using chalconic derivatives as sensitizing dyes. The chalconic derivatives containing the 4-N,N-dimethyl group present two absorption bands with maxima located at the 241 nm and 416 nm, with maximum intensity in the visible region and absorption coefficient of the order 104 cm-1. The analysis of the current-voltage characteristics of the DSSCs with the respective chalconic derivative indicattes the best solar energy conversion efficiency (η = 0.4%), due to the fact that it has the highest absorption value in the band located in the visible region. The best short-circuits current density with value of 2.45 mA/cm2. are obtained for the DSSCs sensitized with chalconic derivative containing 4-N, N-dimethyl SH group.

Yttrium oxide nanoparticles were conjugated separately to zinc tetracarboxy phthalocyanine (ZnPc(COOH)4) to form Y2O3:ZnPc(COOH)4 assemblies. The triplet quantum yields and lifetimes of the phthalocyanines increased following conjugation. The resulting assemblies exhibited stronger fluorescence with increased quantum yields, reaching up to 33.44% compared to ZnPc(COOH)4 alone, which has a value of 0.3%. The triplet quantum yields increased from Phi T = 14.8% for ZnPc(COOH)4 to Phi T = 29.9% and 30.9% for the Y2O3:ZnPc(COOH)4 assemblies. The lifetimes also became longer for the conjugates compared to ZnPc(COOH)4 alone. These studies open new avenues for the development of next-generation phosphorescent materials with tailored functionalities for both industrial and medical applications.

In this study, zinc phthalocyanine (ZnPc) and copper phthalocyanine (CuPc) thin films fabricated by drop casting (DC) and close space sublimation (CSS) have been investigated and compared with ZnPc and CuPc solutions in formic acid (29 µmol/L). The results show that the CSS method produces films with improved molecular ordering, enhanced surface uniformity, superior optical and morphological properties compared to those obtained by drop casting. Moreover, CSS allows a precise and reproducible deposition, resulting in thinner, homogeneous layers with strong substrate adhesion and fewer defects. Optical characterization confirms that CSS films display high transparency (~90%), a sharp Q-band around 680 nm, and a fluorescence maximum at ~825 nm with the strongest emission intensity.In contrast, DC films show lower transparency (<70%), a slightly shifted Q-band (~675 nm), and similar emission around 825 nm. The fluorescence is strongly thickness-dependent: at ~100 nm, the emission band appears at 795 nm, while films thicker than 300 nm exhibit a red-shifted maximum at ~825 nm. AFM analysis further demonstrates the influence of deposition method: CSS yields smoother films with tunable morphology, while DC produces rougher, less controllable surfaces. Overall, CSS is shown to be the more effective approach for fabricating high-quality phthalocyanine films for optoelectronic applications such as photovoltaics and sensors.

This paper presents the synthesis of ZnPc(COOH)4/Ch/Fe3O4 supramolecular architectures at various ZnPc(COOH)4 and Ch/Fe3O4 concentrations explored in the synthesis process. Ch/Fe3O4 composite was prepared by a simple solution mixing-evaporation method. The validation of the synthesis was achieved through FTIR analysis and UV-Vis spectroscopy. FTIR of composite indicated an interaction between chitosan and Fe3O4 NPs. The chemical interaction of ZnPc(COOH)4 with Ch/F3O4 composite is confirmed by the shift of the signal from v(C=O)) of protonated COOH groups in the FTIR spectrum of ZnPc(COOH)4, associated with spitting, to (νsym(COO)) and (νasym(COO)) that correspond to deprotonated carboxylic group. The absorption spectra of ZnPc(COOH)₄ revealed IR Q band with two subbands situated at 640 nm 700 nm. Also, the effect of various ZnPc(COOH) and Ch/Fe3O4 concentrations on absorbance of ZnPc(COOH)4/Ch/Fe3O4 supramolecular architecture is discussed.

This study investigates the influence of solvent on the photophysical properties of a tetranitro zinc phthalocyanine derivative synthesized through a cyclotetramerization reaction using 4-nitrophthalonitrile and zinc acetate in N,N-dimethylaminoethanol. Its photophysical behavior was systematically analyzed in DMSO, DMSO:H₂O (1:1), NMP, and NMP:H₂O (1:1) media using UV-Vis absorption, fluorescence, and phosphorescence spectroscopy. The UV-Vis spectra revealed the presence of a single, intense Q-band around 700 nm, whose position and intensity depend on the solvent polarity and the degree of hydrogen bonding, indicating solvent-dependent aggregation behavior. Fluorescence measurements showed well-defined emission bands only in pure solvents (DMSO and NMP), while in aqueous mixtures the fluorescence was strongly quenched, suggesting non-radiative processes and possible hydrogen-bond-assisted aggregation. Room-temperature phosphorescence, recorded under pulsed excitation with a xenon lamp, confirmed the population of triplet states, with emission bands around 850 nm and lifetimes on the order of tens of microseconds, depending on the solvent environment. The phosphorescence intensity was notably higher in DMSO compared to NMP, indicating differences in triplet-state stabilization. These results demonstrate that solvent polarity, hydrogen bonding, and the presence of water significantly influence both, singlet and triplet excited-state dynamics, of the tetranitro zinc phthalocyanine derivative. The findings provide valuable insights for optimizing the photophysical response of phthalocyanine-based systems in light-harvesting, photodynamic therapy, and optoelectronic applications, where solvent tuning can be employed to control emission properties and excited-state lifetimes.

In this study, we report the synthesis and comprehensive characterization of pure Yb₂O₃, pure CeO₂, and mixed Yb₂O₃:CeO₂ nanoparticles with varying molar ratios, prepared via a simple sol-gel method followed by thermal treatment. Structural analysis by X-ray diffraction (XRD) confirmed the formation of cubic crystalline phases for all samples, with crystallite sizes ranging from 24.5 nm for pure Yb₂O₃ to 5.1 nm for the 1.0Yb₂O₃:0.5CeO₂ composition, indicating that Ce incorporation leads to significant crystallite size reduction. The addition of CeO₂ induced lattice strain and increased dislocation density, reflecting the presence of structural distortions and enhanced defect formation, which suggest the successful incorporation of Ce ions into the Yb₂O₃ matrix and the formation of solid solutions. X-ray photoelectron spectroscopy (XPS) analysis confirmed the chemical composition and oxidation states of the constituent elements. The O 1 s spectra revealed contributions from lattice oxygen and oxygen vacancies, indicating defect-related features that may influence the electronic properties. The Ce 3d spectra displayed a dominant Ce4+ component with the presence of Ce3+ species, implying partial reduction, redox activity, and the potential for oxygen storage or catalytic applications. Yb 4d spectra confirmed the presence of Yb3+ without evidence of Yb2+ species. The experimental atomic ratios closely matched the theoretical stoichiometries, validating the compositional homogeneity and stability of the synthesized nanomaterials. Overall, the synthesized Yb₂O₃:CeO₂ nanomaterials exhibit tunable structural, electronic, and defect properties, making them promising candidates for applications in catalysis, gas sensing, and energy-related devices, where defect engineering and redox activity are critical for enhancing performance.