Sm3+ activated La3GaO6 (LGO) phosphors were successfully synthesized via an eco-friendly solution combustion technique. Rietveld refinement of the X-Ray Diffraction (XRD) data verified that the sample crystallizes in a single-phase orthorhombic structure with Cmc21 symmetry. The refinement results indicate that Sm3+ ions effectively substitute La3+ lattice sites without inducing any noticeable structural distortion, demonstrating good dopant incorporation. Under UV excitation, the phosphor materials produce a dominant reddish-orange emission at 610 nm, which is assigned to the 4G5/2 -> 6H7/2 transition. The luminescence intensity initially increases with Sm3+ doping concentration, reaching a maximum at 4 mol % and subsequently decreases at higher doping levels due to concentration quenching, which is predominantly governed by dipole-dipole interactions. The chromaticity coordinates plotted on the Commission Internationale de l'Eclairage (CIE) diagram exhibit a gradual transition from orange to red emission as the Sm3+ doping increases. These luminescence characteristics demonstrate that Sm3+-activated La3GaO6 phosphors are promising candidates for solid-state lighting applications.

Trivalent samarium doped Gd3GaO6 (GGO) phosphors were synthesized via solution combustion synthesis with Sm3+ ions concentration varying between 1 and 6 mol %. X-ray diffraction (XRD) and photoluminescence studies were conducted to characterize structural and optical attributes. The orthorhombic phase belonging to Cmc2(1) space group of the considered phosphors was confirmed by X-ray diffraction and Rietveld analysis. Morphological and compositional features were inspected by Field emission scanning electron microscope (FESEM) and Energy dispersive X-ray (EDX) techniques, respectively. The major emission peak at 609 nm related to (4)G(5/2) -> H-6(7/2) transition was observed which is responsible for reddish-orange emission of the phosphors. The PL spectra further display three lines centered at 568 nm, 655 nm and 714 nm corresponding to (4)G(5/2) -> H-6(5/2), (4)G(5/2) -> H-6(9/2) and (4)G(5/2) -> H-6(11/2) transitions, respectively. The critical energy transfer distance (R-c = 20.92 & Aring;) and energy transfer mechanisms (dipole-dipole interaction) were explained based on Dexter theory. Lifetime analysis shows that the decay time steadily decreases with increasing concentration of trivalent samarium ions due to enhanced non-radiative transitions. Additionally, photometric parameters including chromaticity coordinates and color purity values in the range 79-82 % were determined demonstrating suitability of GGO:Sm3+ phosphors for reddish-orange emission in warm white LED applications.

Achieving efficient luminescence from lanthanide complexes depends on how effectively the coordination environment can facilitate excitation and direct energy into the 4f manifold. Although numerous reviews have addressed individual aspects of lanthanide photophysics, discussions are often dispersed across specialized topics, making it difficult to view the underlying processes as a connected framework. This Review brings these elements together by examining the roles of f-f, f-d and charge-transfer transitions alongside ligand-centered sensitization in a single, cohesive context. The relationship between molecular structure and energy migration is discussed in terms of both Förster and Dexter mechanisms, highlighting how these pathways often operate together in real coordination systems. Different sensitization routes including ILCT, LMCT, MLCT and related charge-transfer states are examined together with chemical approaches used to limit non-radiative decay, such as ligand modification. In addition, commonly used color parameters are outlined to show how emission color and purity can be quantitatively evaluated, providing a bridge between spectroscopic data and visual performance. By viewing these factors collectively rather than in isolation, the review illustrates how coordination chemistry can be used to systematically tune emission behavior and relates these principles to current application areas of luminescent lanthanide complexes.

To understand different properties of Eu3+ ions in inorganic phosphors, a series of red emitting Gd3GaO6:Eu3+ was synthesized via solution combustion method. XRD patterns supported by Rietveld refinement revealed successful formation of crystalline sample with orthorhombic structure and Cmc21 space group. Microstructural features and elemental mapping of samples were examined by means of FE-SEM and EDX techniques. Photoluminescence spectra of Eu3+-activated Gd3GaO6 revealed red emission at 612 nm due to the 5D0 -> 7F2 transition under excitation at 261 nm. A decrease in emission intensity was observed after doping levels exceed 4 mol% indicating energy transfer between activator ions results in concentrating quenching governed via dipole-dipole interactions. The intensity parameters Omega 2 and Omega 4 defined by Judd Ofelt theory were calculated utilizing emission spectra to investigate coordination symmetry around Eu3+ ions. The photoluminescence decay profile was well described by bi-exponential decay function. The activation energy 0.19873 eV suggests good thermal stability of GGO:4 mol% Eu3+ phosphor. The high color purity (98.15 %) inferred from CIE coordinates revealed their applicability in white light emitting diodes.

In this work, three Tb(iii) complexes, TbA, TbM and TbD, were synthesized using 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione (TTBD) and pyrazine (pyz) as antenna moieties. Structural characterizations (elemental (CHN), infrared and NMR) confirmed that TbA and TbM are mononuclear and share an identical structural framework, while TbD forms a dinuclear species where pyrazine serves as a bridging ligand. Photoluminescent (PL) features of the complexes were studied through electronic absorption, PL and lifetime analyses. All three complexes emit the characteristic emissive peaks of Tb(iii) ions along with a broad ligand-centered band due to the sensitizer energy difference. Upon incorporation of chromophores, the emission color shifts dramatically towards near-white, showcasing tunable optical behavior. The Judd-Ofelt analysis supported these photophysical observations theoretically. Detailed decay studies provided radiative lifetime data and insights into the qualitative energy transfer efficiency from the ligand to the metal. Bandgap analysis using Tauc's method, supported by DFT calculations revealed semiconducting behavior with a value of similar to 3.2 eV. These outcomes highlight the possibility of these complexes for use in photonic and optoelectronic applications, highlighting how pyrazine incorporation enables fine-tuning of Tb(iii) luminescence to achieve near-white emission.

This research investigation reports the synthesis of europium complexes with chosen β-diketone referred as BPTD (1-(4-bromophenyl)-4,4,4-trifluorobutane-1,3-dione) and ancillary ligands (–N donors) as 2,2′-bipyridine (Bpy), 1,10-Phenanthroline (Phen), 2,9-dimethyl-1,10-phenanthroline (DmPhen) and 2,9-dibromo-1,10-phenanthroline (DbPhen). Elemental, FTIR, UV, Photoluminescence spectroscopy and TGA analysis are utilized to characterize the complexes. IR and NMR are employed to determine structure information about complexes. The optical bandgap measurements in DCM show the optically active wide-bandgap behavior of complexes. The luminescence intensity of the Europium centered luminescence clearly shows the good efficiency of energy transfer. Calculations using density functional theory demonstrated that the luminescence of Eu(III) complexes originates from the attenuation effect of β-diketonates that rigidifies the coordination surroundings about europium ion and reduces non-radiative energy loss suggesting that optical excitation populates ligand centered singlet and triplet states instead of metal centered states. The intensity of the f–f transitions in the wavelength spectrum of absorption was examined using the Judd–Ofelt hypothesis. Sets of phenomenological Ωλ intensity values can be obtained.

Incorporating synthetic and natural polymers with metal oxide nanoparticles (NPs) can significantly alter electrical, optical, catalytic, antibacterial, mechanical, physical, and magnetic properties. In this study, nanocomposites (NCs) containing polyaniline (PANI), a conducting polymer, Chitosan (CS), a natural polymer, and ZnO metal NPs were synthesized using in situ chemical oxidative polymerisation technique. The multifunctional properties of these NCs, including antibacterial, photocatalytic, anticorrosive, and magnetic, were investigated. The photocatalytic degradation efficiency of methylene blue dye (MBD) was evaluated under UV and sunlight and found to be higher in sunlight. The MBD degradation efficiency reached 74.57% in 6.4 h in UV light and 89.62% in 5.0 h in sunlight. The synthesized NCs exhibited a 'magnetic susceptibility' (chi) of 0.035, indicating paramagnetic behavior. The optical band gap of the NCs was 2.9 eV, lower than that of pure PANI (3.8 eV) and ZnO NPs (3.35 eV). The zone of inhibition (14.0 mm) was measured against S. aureus (Gram-positive) bacteria at a concentration of 4.5 mg/mL. The NCs demonstrated anticorrosive activity against mild steel in 1.0 M H2SO4, achieving an inhibition efficiency of 90.34% at 10 ppm. This study leads to the development of NCs with significant potential for water purification, environmental remediation, anticorrosive coatings, and applications requiring conductive and magnetic properties.

Compounds with common depiction [Tb(BPTD)3.L], (where BPTD represents “1-(4-bromophenyl)-4,4,4-trifluorobutane-1,3-dione”; and L denotes N-donor neutral auxiliary moeities viz. “2,2’-dipyridyl (Bpy, T1), “1,10-phenantroline (Phen, T2), “2,9-dimethyl-1,10-phenanthroline (DMPhen, T3) and 2,9-dibromo-1,10-phenanthroline (DBPhen,” T4). The complexes were synthesized by reaction of Tb(III) chloride salt with BPTD in the occurrence of respective ancillary ligands. The arrangement and molecular structure of the synthesized terbium complexes are established by elemental analysis, IR spectroscopy, chemical analysis such as NMR and thermogravimetric analysis. The wavelength of emission centered at 545 nm, consistent to the 5D4 → 7F5 transition. The influence of different nitrogen-donor ligands on the photophysical behavior of the complexes was systematically investigated, with particular emphasis on the emission intensity and luminescence lifetime of the central Tb³⁺ ion. The thermal stability and degradation performance of all compounds were examined in detail. In addition, the study highlights the applicability of density functional theory calculations in predicting and interpreting key properties of these complexes, including optimized molecular structures, electronic energies and spectroscopic features.

Guar gum (GG) is a galactomannan polysaccharide which is extracted from seeds of guar plants. GG is a useful biopolymer for modern drug delivery systems and hence, has attracted interests of researchers and pharmaceutical companies. The present review work summarizes available knowledge on GG-based systems and also describes key developments in the design and application of such systems. The review provides valuable knowledge for the researchers and the pharmaceutical companies to enhance therapeutic developments. The review highlights key physicochemical characteristics of the GG which make GG an important substance for developing various drug carriers. The review provides analysis on various GG-based formulations such as hydrogels, nanoparticles, microparticles, films, but not limited thereto. The authors have described modifications and development of various GG-based drug delivery systems alongwith their key advantages and shortcomings. Additionally, the review illustrates a wide range of therapeutics which can be delivered with the help of GG-based carriers such as small molecules, peptides, proteins and nucleic acids, but not limited thereto. The review also describes utility of GG-based formulation for targeted and controlled release systems with improved drug stability. The review concludes by describing solutions for existing challenges in this field and identifies key areas for future research studies to unlock the potential of guar gum-based drug delivery systems.

Three Sm(iii)-complexes featuring β-diketone ligand 4,4,4-trifluoro-1-thienyl-1,3-butadionate (TTBD) were studied for their potential as visible-light emitters. Utilizing pyz (pyrazine) as an ancillary ligand, two mononuclear compounds i.e. binary (SmA) and ternary (SmM) along with a dinuclear compound (SmD) were synthesized. Elemental (CHN), IR and NMR analyses confirmed that two complexes (SmA and SmM) are mononuclear with identical structural frameworks, whereas SmD forms a dinuclear species with pyrazine acting as a bridging ligand. The optical band gaps were measured from UV-vis absorption using Tauc's relation corresponding to HOMO-LUMO (Highest Occupied Molecular Orbital-Lowest Unoccupied Molecular Orbital) transitions. Photophysical investigations in solution phase using dichloromethane (DCM) solvent revealed characteristic emissions of Sm(iii) ions under UV excitation, due to 4G5/2 → 6H j (j = 5/2, 7/2, 9/2, 11/2) transitions in visible region. All complexes displayed intense luminescence with notably high lifetimes (0.063 ms), similar to the most efficient Sm(iii)-based emitters reported. Radiative lifetimes and qualitative ligand-to-metal energy transfer (ET) efficiencies were deduced from time-resolved measurements, confirming that TTBD and pyz function effectively as sensitizing ligands. Colorimetric analysis based on emission spectra yielded CIE coordinates indicative of orange-red luminescence, typical of Sm(iii) ions. Correlated color temperature (CCT) values further suggest their suitability as warm-light emitters. thermogravimetric analysis (TGA) revealed thermal stability up to ∼224-231 °C, emphasizing their promise in thermally stable optoelectronic devices.

Octacoordinated luminescent Samarium(III) complexes described by empirical formula [Sm(L)(3)& centerdot;(N)] have been synthesized, where L = 4,4,4-trifluoro-1-phenyl-1,3-butanedione (TFPD) and N represents ancillary ligands including 2,2 '-bipyridine (Bpy) and its derivatives 5,5 '-dibromo-2,2 '-bipyridine (B1), 5-bromo-5 '-(3,4-(ethylenedioxy)thien-2-yl)-2,2 '-bipyridine (B2) and 5,5 '-bis(3,4-(ethylenedioxy)thien-2-yl)-2,2 '-bipyridine (B3). This study investigates how structural variations in secondary ligands influence the photophysical and electronic properties of synthesized complexes. Synthesized materials were comprehensively characterized by elemental analysis, FTIR, H-1 NMR spectroscopy absorption, photoluminescence and thermogravimetric analysis. Optical band gap values ranging from 2.95 to 3.40 eV confirm their semiconducting nature and potential suitability for optoelectronic applications. Upon excitation at 367 nm, all complexes exhibited characteristic Sm(III) emissions at similar to 564, similar to 600, similar to 648 and 703 nm, corresponding to (4)G(5/2) -> H-6(5/2), H-6(7/2), H-6(9/2) and H-6(11/2) transitions, respectively, with most intense emission observed at similar to 648 nm. Commission Internationale de l'& Eacute;clairage (CIE) chromaticity coordinates revealed warm orange red emissions, affirming their applicability for use in light emitting and display technologies. Overall, the synergistic effects of fluorinated beta-diketonate and functionalized bipyridine ligands enhance both luminescent efficiency and material stability, making these complexes promising candidates for next generation photonic and semiconductor devices.

Four ternary Sm(III) complexes (A1-A4) have been synthesized incorporating a heteroaryl-beta-diketone TTBD (4,4,4-trifluoro-1-thiophen-2-yl-butane-1,3-dione) and four distinct bidentate auxiliary ligands (Phen, Neo, BP and BC). Molecular structure of these complexes is confirmed through preliminary analysis (CHN), Powder XRD and various spectroscopic techniques (XPS, IR and H-1 NMR). Obtained optical (UV) and electrochemical (CV) energy gaps similar to 3 eV specifies the semiconducting properties possessed by these trivalent samarium complexes and strong correlation between the findings of both these techniques affirms the reliability of the results. The hyperintense transition observed similar to 648 nm, attributed to Delta J = 2 transition, reveals significantly non-symmetric chelation surroundings of the central ion, which contributes towards the orange-red luminescence characteristic of Sm(III) complexes. Complex A4 shows the weakest luminescent output, likely due to the presence of a bulky, sterically hindered neutral ligand (BC). Interestingly, A4 is found to emit pink luminescence due to broad ligand based band which suggests its possible utility in OLEDs. The probable Energy Transfer (ET) path demonstrates the efficient sensitizing effect of the heteroaryl TTBD diketone. Prepared complexes exhibit semiconducting property, a considerably extended luminescence lifetime and chromaticity coordinates in the orange-red zone, which collectively suggests their possible utility in optoelectronic devices.

In this study, two coumarin-naphthalimide-based probes, L1 and L2, are designed, and their sensing capabilities are systematically investigated. Probe L1 exhibits a distinct fluorescence 'turn-on' behavior upon interaction with Be2+ and Zn2+ ions, accompanied by appreciable binding constants. In contrast, L2 exhibits a selective 'turn-on' emission response to the Ga3+ ion, further illustrating its high selectivity for valine. Both probes display low detection limits and high binding constants. Specifically, L1 shows a detection limit of 42 nM and 24 nM for Be2+ and Zn2+ ions, respectively. On the other hand, L2 exhibits a detection limit of 64 nM for Ga3+ ion and 120 nM for valine. The interaction of both probes with their respective analytes is further validated through 1H NMR spectral and mass spectrometric analyses, while Job's plots confirm a 1:1 binding stoichiometry. A detailed DFT study has been carried out to support the binding modes of both probes with metalanalytes. The sensing ability of L1 and L2 was successfully extended to colorimetric assays and paper-strip-based detection methods, highlighting their potential for real-world applications.

Four mononuclear dysprosium(III) complexes, formulated as [Dy(TFPD)(3)N] (TFPD = 4,4-trifluoro-1-phenyl-1,3-butanedione; N = Phen and its derivatives P1-P3), have been successfully synthesized via a facile one-pot strategy. Elemental and spectroscopic analyses (FTIR and NMR) confirm effective ligand coordination, affording an eight-coordinated Dy(III) center. The photophysical behavior was systematically investigated through UV-visible absorption spectroscopy, steady-state & time-resolved emission measurements, enabling detailed evaluation of the characteristic 4f-4f transitions of Dy3+. The complexes exhibit characteristic dual emission bands at similar to 480 nm (F-4(9/2) -> H-6(15/2)) and similar to 575 nm (F-4(9/2) -> H-6(13/2)), corresponding to magnetic dipole and hypersensitive electric dipole transitions, correspondingly. Relative intensity modulation of these transitions enables fine control over emission chromaticity, approaching near-white light generation. Electrochemical and optical band gap analyses (2.98-3.35 eV) reveal semiconducting characteristics, indicating potential integration into optoelectronic architectures. The correlation between coordination environment, asymmetry around the Dy(III) center and enhanced electric dipole emission underscores the structure property relationship governing luminescent performance. Collectively, these findings establish the present Dy(III) beta-diketonate systems as promising multifunctional materials for tunable photonic and solid-state lighting applications.

Green-emitting Tb3+-doped Gd3GaO6 phosphors were fabricated through a low-temperature solution-combustion approach utilizing urea as the fuel. Powder XRD analysis suggested an orthorhombic structure with the Cmc21 space group. Crystallite size was determined using the Scherrer's formula and W-H plot. Surface topography was examined utilizing the FESEM technique, and EDX data confirmed the uniform incorporation of Tb3+ ions into the Gd3GaO6 lattice with proper stoichiometry. A bright green emission was exhibited by phosphors at 543 nm, attributed to the 5D4 → 7F5 transition upon irradiation with near ultraviolet light at 272 nm. The observed concentration quenching at 3 mol% Tb3+ in the Gd3GaO6 matrix was attributed to non-radiative energy transfer between the neighbouring Tb3+ ions, which became significant at higher doping levels. The quenching observed beyond the optimum concentration is primarily attributed to dipole-dipole interactions between adjacent Tb3+ ions. The CIE chromaticity coordinates are located the green region, and the calculated CCT value (4500-5500 K) lies in the cool temperature range, making this phosphor a suitable candidate for cool white-solid state lighting and display devices.

[2Fe2S] synthetic model complexes serve as benchmarks for intermediates proposed in enzyme catalysis, and elucidate how structural effects influence the electronic structure of the cluster. Access to [2Fe2S]1+ complexes has been synthetically challenging, with most clusters degrading or aggregating upon reduction. Here, we report a 2Fe2S cluster ligated by a dinucleating bis((3-diketiminate) cyclophane in two oxidation states, with the reduced congener being valence localized based on X-ray diffraction and Mo & uml;ssbauer data.

Octacoordinated terbium complexes were synthesized by mixing a 4,4,4-trifluoro-1-phenyl-1,3-butanedione with ancillary ligands in a 3:1:1 M ratio. The effects of 1,10-phenanthroline and its derivatives on the optoelectronic properties of the complexes were studied. Structural characteristics of the complexes were elucidated through a combination of elemental analysis, infrared (IR) spectroscopy and proton nuclear magnetic resonance (1H NMR) spectroscopy. Absorption studies and cyclic voltammetry experiments demonstrated applications of these complexes in semiconducting materials. Thermogravimetric analysis confirmed their thermal stability. Emission spectra recorded under various excitation wavelengths revealed tunability in the CIE color coordinates. Green luminescence observed in the P1-P4 complexes arises primarily from the characteristic 5D4 -> 7F5 transition of Tb (III) ion. Luminescence decay measurements at this emission wavelength confirmed the presence of a single luminescent centre in each complex. Owing to their intense green emission and favourable thermal and optoelectronic properties, these terbium complexes hold promise as efficient light-converting molecular materials for use in display technologies and lighting applications.

A novel series of four luminescent Sm3+ complexes having empirical formula [Sm(TFPD)3Z] were successfully prepared and fully characterized. Here, TFPD (4,4,4-trifluoro-1-phenyl-1,3-butanedione) serves as primary β-diketonate ligand, while ancillary ligands (Z) are functionalized 1,10-phenanthroline derivatives (Phen, P1, P2 and P3). Systematic modulation of the ancillary ligand framework enabled clear elucidation of structure–property relationships, particularly the influence of ligand environment on photophysical and electronic behavior. Comprehensive characterization using elemental analysis, FTIR, 1H NMR and TGA confirmed successful formation and appreciable thermal stability. Synthesized materials exhibit a semiconducting nature, confirmed by optical band gap values (2.89 to 3.39 eV). Upon UV excitation, all compounds display characteristic intense orange–red emission centered around 648 nm, corresponding to the dominant 4G5/2→6H9/2 transition of Sm3+. The CIE 1931 chromaticity coordinates further reveal tunable emission spanning red (SP1, SP2), reddish–orange (SP3) and pink (SP4) regions, demonstrating effective color modulation through ligand engineering. Overall, these findings highlight the pivotal role of ancillary ligand design in governing energy transfer efficiency and emission characteristics, establishing this new class of Sm3+ coordination compounds as promising candidates for optoelectronic and semiconducting applications, particularly in advanced display and solid state lighting technologies.

The trivalent erbium doped Y3GaO6 nanophosphors were successfully prepared using solution combustion method. The synthesized products were characterized through detailed spectroscopic and structural analysis. Structural studies of considered samples were elucidated by means of X-ray Diffraction (XRD) as well as Rietveld refinement procedure which confirmed orthorhombic phase with Cmc2(1) space group. Morphological and elemental analyses were carried out using field-emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDX) techniques, respectively. Photoluminescent features of samples were thoroughly examined revealing strong absorption at 377 nm. Upon excitation at this wavelength, phosphor materials demonstrated characteristic emissions of Er3+ ions primarily corresponding to transition S-4(3/2)-> I-4(15/2). Furthermore, investigation of concentration quenching effect showed that sample doped with 4 mol % Er3+ revealed highest luminescence intensity. The observed concentration quenching was credited to dipole-dipole interactions among Er3+ activator ions. The calculated CIE chromaticity coordinates (x, y) fall within green region indicating potential application of synthesized phosphor in near-UV excited white light-emitting diodes (WLEDs).

The CuO nanoparticles (NPs) were synthesized using a facile Sol-gel method. Characterization was performed using FTIR, UV-visible spectroscopy, XRD, AFM, and SEM techniques. Both XRD and SEM analyses indicate an average particle size ranging between 25 and 30 nm. CuO NPs provide 98.7% corrosion inhibition efficiency at a concentration of 100 ppm for Al sheet in 0.5 M HCl solution. Antibacterial activity was tested against Gramnegative bacteria E. coli and Gram-positive bacterium S. aureus and compared with six standard antibiotics (hexa disk) No antibacterial activity was seen against E. coli. The NPs exhibited an inhibitory zone of 17 mm towards S. aureus. NPs show an indirect band gap of 2.31 eV. Non-linear relationship between change in weight and magnetic field suggests presence of complex magnetic interactions within NPs. NPs exhibit high photocatalytic activity (80%) towards Methylene Blue dye under UV light. With enhanced photocatalytic, magnetic, antibacterial, and anticorrosive qualities, CuO NPs are proven to be multifunctional nanomaterials.