UV-vis Emission Research Articles

Synthesis and spectroscopic characterization of 2-furancarbothioamide: N-(4-fluorophenyl)furan-2-carbothioamide

This investigation deals with an alternative thionation synthetic strategy for the preparation of N-(4-fluorophenyl)furan-2-carbothioamide using elemental sulphur and applying the Willgerodt-Kindler reaction. The carbothioamide was obtained with ca 30% yield assessing the purity (higher than 90%) with GC/MS spectrometry, and the compound was fully characterised by NMR (1H, 13C), FTIR and UV-visible spectroscopies. Indeed, 1H-NMR spectroscopic analysis demonstrated that a single conformer with anti-anti geometry was formed attributed to the observation of only one N-H signal (9.37 ppm) of the NH-C=S group and, FTIR spectroscopy (N-H stretching at 3372 cm−1) also reinforces this observation. UV-visible absorption and fluorescence emission spectra were recorded in different polar and nonpolar solvents (acetonitrile, ethanol and n-heptane) and the λ0,0 cross point displays a bathochromic shift of 11 nm with the increasing solvent polarity. The fluorescence quantum yield (φf) has been measured at room temperature concluding that this carbothioamide derivative is not a fluorescent compound showing a φf value of 0.0002. Finally, theoretical calculations have been carried out to estimate the NMR chemical shifts as well as vibrational frequencies values of the anti-anti isomer and these values were compared with the experimental data obtaining satisfactorily correlations.

Carbonized Polymer Dots: Influence of the Carbon Nanoparticle Structure on Cell Biocompatibility.

Carbonized polymer dots (CPDs) were obtained by using microwave irradiation under the same conditions. However, different carbogenic precursors were used, such as aromatic diamine molecules, ortho-phenylenediamine (o-OPDA), and 3,4-diaminobenzoic acid (3,4-DABA). Both carbon nanoparticles showed different structural results based on Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, and atomic force microscopy analyses. However, there are similar spectroscopic (UV-visible and fluorescence emission) profiles. The photophysical results, like quantum yield (QY) and fluorescence lifetime, were not identical; CPDs-OPDA has a higher QY and fluorescence lifetime than CPDs-3,4-DABA. CPDs-3,4-DABA presents a more hydrophobic character than CPDs-OPDA and has a more negative superficial charge. Cell viability studies in both standard and tumor lines demonstrated higher cytotoxicity from CPDs-OPDA than that from CPDs-3,4-DABA. The oxidative stress identified in cells treated with CPDs-OPDA was based on reactive oxygen species and associated with nitric oxide production. CPDs-3,4-DABA showed more DPHH inhibition than CPDs-OPDA, indicating the antioxidant activity of CPDs.

CuO/Sb2S3 Nanoarchitectures for Enhanced Charge Generation/Separation for Photoelectrochemical Hydrogen Evolution

Developing an efficient photocathode system using abundant earth materials is crucial for the effective process of Photoelectrochemical (PEC) water splitting. Achieving successful charge transfer between heterojunctions is a key consideration in creating an innovative photocathode that considers cost-effectiveness, material abundance, and PEC performance. In our study, we synthesized a p-type narrow band gap photocathode using copper oxide (CuO) with an energy gap (Eg) of 1.5 eV through a hydrothermal method. We then enhanced its performance by decorating it with antimony sulfide (Sb2S3) nanospheres (NSs) using a simple chemical bath deposition (CBD) technique, resulting in the formation of a CuO/Sb2S3 NSs heterojunction.The fabricated heterojunction demonstrated superior PEC performance compared to the bare CuO. Specifically, we observed a significant increase in photocurrent density for the CuO/Sb2S3 NSs photocathode (J = -1 mA.cm-2) compared to CuO alone (J = -0.3 mA.cm-2) at a standard potential of 0 V vs RHE in a 0.5 M Na2SO4 solution with a pH of 6.85. This improvement can be attributed to the enhanced generation and separation of charge carriers. Furthermore, the CuO/Sb2S3 heterojunction exhibited remarkable photostability over a period of 2.5 h, with no degradation in photocurrent density. The Sb2S3 acted as a sensitizer, reducing the recombination rate of electron-hole pairs (e-/h+) within the CuO/Sb2S3 NSs, thereby enhancing the overall performance. The CuO/Sb2S3 NSs photocathode exhibited an ABPE% of 0.1%, while the ABPE% for CuO alone was 0.03%. This indicates a significant improvement in the performance of the CuO/Sb2S3 NSs photocathode. Onset potential (Eonset) was also observed to shift in a positive direction in CuO/Sb2S3 NSs as compared to CuO only. Eonset for the films followed a trend having CuO/Sb2S3 NSs (0.85 VRHE) > CuO (0.78 VRHE). Notably, this improvement is attributed to increased light absorption and a reduced recombination rate compared to the pristine CuO photocathode. Moreover, electrochemical impedance spectroscopy (EIS) studies provided evidence of enhanced electron transfer rates occurring at the interface between the heterojunction and the electrode/electrolyte interface. UV-Visible and photoluminescence (PL) emission spectra results indicated that the CuO/Sb2S3 NSs heterojunction exhibited an extended absorption spectrum and a reduced rate of recombination, further supporting the enhanced performance. Additionally, electrochemical impedance spectroscopy studies revealed lower charge transfer resistance in the CuO/Sb2S3 NSs heterojunction compared to CuO alone.These findings open up new avenues for the development of novel photocathodic materials and heterojunctions utilizing copper-based binary oxides/chalcogenides for efficient solar harvesting applications.References(1) Kumar, M.; Singh, A.; Meena, B.; Sahu, P. K.; Subrahmanyam, C. Decoration of Spherical Sb2S3 over CuO Nanoflakes for Efficient Photoelectrochemical Hydrogen Generation. Results Eng. 2023, 101513. https://doi.org/10.1016/j.rineng.2023.101513.(2) Kumar, M.; Meena, B.; Subramanyam, P.; Suryakala, D.; Subrahmanyam, C. Emerging Copper-Based Semiconducting Materials for Photocathodic Applications in Solar Driven Water Splitting. Catalysts 2022, 12 (10), 1198. https://doi.org/10.3390/catal12101198.(3) Kumar, M.; Meena, B.; Subramanyam, P.; Suryakala, D.; Subrahmanyam, C. Recent Trends in Photoelectrochemical Water Splitting: The Role of Cocatalysts. NPG Asia Mater. 2022, 14 (1), 88. https://doi.org/10.1038/s41427-022-00436-x. Figure 1

Understanding the xenon primary scintillation yield for cutting-edge rare event experiments

Xenon scintillation has been widely used in rare event detection experiments, such as in neutrinoless double beta decay, double electron captures and dark matter searches. Nonetheless, experimental values for primary scintillation yield in gaseous xenon (GXe) remain scarce and dispersed. The mean energy required to produce a scintillation photon, w sc, in GXe in the absence of recombination has been measured to be in the range of 34–111 eV. Lower w sc-values were reported for α-particles when compared to electrons produced by γ- or x-rays. Since w sc is expected to be similar for x-, γ-rays or electrons and almost equal to that obtained for α-particles, the above difference can not be understood. In addition, at present one may also pose the question of a dependence of w sc on photon energy. We carried out a systematic study on the absolute primary scintillation yield in GXe under reduced electric fields in the 70–300 V cm-1 bar-1 range and near atmospheric pressure, 1.2 bar, supported by a robust geometrical efficiency simulation model. We were able to clear-out the above standing problems: w sc was determined for x/γ-rays in the 5.9–60 keV energy range as well as for α-particles in the 1.5–2.5 MeV range, and no significant dependency neither on radiation type nor on energy has been observed. Our experimental w sc-values agree well with both up-to-date simulations and literature data obtained for α-particles. The discrepancy between our results and the experimental values found in the literature for x/γ-rays is discussed in this work and attributed to unaddressed large systematic errors in those previous studies. These findings can be extrapolated to other gases, and have impact on experiments such as double beta decay, double electron capture and directional dark matter searches while also on potential future detection systems such as DUNE-Gas. Only assuming the VUV emission band as is the case of most of the literature values, a mean w sc-value of 38.7 ± 0.6 (sta.)+7.7 -7.2 (sys.) eV was obtained. If the UV-VIS emission band is to be considered, the average energy to produce a photon was determined to be w 2nd = 43.5 ± 0.7 (sta.)+8.7 -8.1 (sys.) eV and w 3rd = 483 ± 7 (sta.+110 -105 (sys.) eV, in the VUV and UV-VIS bands, respectively.

Synthesis and Application of Specific N2H4 Fluorescent Probes with AIE Effect Based on Pyrazole Structure.

Two fluorescent probes, Y1-2 were synthesized from 2-acetonaphthone, 4-acetylbiphenyl, and phenyl hydrazine by Vilsmeier-Haack reaction and Knoevenagel condensation. Their recognition efficacies for N2H4 were tested by UV-visible absorption spectroscopy and fluorescence emission spectroscopy. The recognition mechanism were studies by density-functional theory calculations, and the effect of pH on N2H4 recognition was also studied. The results showed that the probe Y1-2 has high selectivity and a low detection limit for N2H4, and the recognition of N2H4 can be accomplished at physiological pH. The probes have had obvious aggregation-induced luminescence effect, large Stokes shift, high sensitivity, and can be successfully applied to live cell imaging.

Structural, spectroscopic, DFT studies, Hirshfeld surface analysis and antibacterial activity of Z-3-(4-bromophenyl)-3-chloroacrylaldehyde

The present paper describes the single-crystal X-ray structure of Z-3-(4-bromophenyl)-3-chloroacrylaldehyde (BCA). Hirshfeld Surface analysis was performed, providing insight into intermolecular interactions for the first time. The compound crystalizes in the monoclinic system with a space group P21/c and unit cell dimensions of a =3.9327(4) Å, b=18.5517(19), c=12.2749(14) and V=894.77(16)Å3. Z-3-(4-bromophenyl)-3-chloroacrylaldehyde was characterized using 13C and 1H NMR spectroscopy, and its thermal stability assessed with a thermogravimetric analyzer. Optical properties were investigated through UV-Visible absorption and emission spectroscopy. Density Functional Theory (DFT) calculations were performed using B3LYP theory with a basis set of SDD. HOMO-LUMO calculations, conceptual DFT and its global reactivity descriptors like hardness, electronegativity and electrophilicity of molecule were studied using G16W software. The energy gap of 4.17eV obtained from HOMO-LUMO molecular orbital energy shows that the compound is hard, stable and reactive. Further, Z-3-(4-bromophenyl)-3-chloroacrylaldehyde also exhibited significant antibacterial activity against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) with a zone of inhibition of 13 ± 1 mm against E. coli and 14 ± 1 mm against S. aureus and the MIC value was found to be 0.55 mg/mL against S. aureus and 1.1 mg/mL against E. coli. The integration of experimental and theoretical approaches in this study enhances the understanding of the versatile applications of BCA across various fields.

Effect of π-extension and halogenation on the optical limiting properties of meso-pyrenylBODIPYdyes

The lack of suitable optical limiters that cover the entire UV-visible-NIR region has motivated research to identify novel efficient and stable optical limiting materials. There has been a strong focus on attenuating the second harmonic of Nd:YAG pulsed lasers at 532 nm on the nanosecond timescale. The photophysicochemical processes of a series of mono- and di-(4-dimethylamino)styryl-meso-pyrenylBODIPY and mono- and di-(4-dimethylamino)buta-1,3-dienyl-meso-pyrenylBODIPY dyes were studied by UV-visible absorption and fluorescence emission spectroscopy, and by determining the fluorescence and triplet state lifetimes. Z-scan measurements were carried out at a fixed concentration of 10 [Formula: see text]M so that the effective nonlinear coefficients, third-order susceptibilities, second-order hyperpolarizabilities and limiting fluences of the dyes can be compared and trends in the structure-property relationships for these optical limiting parameters can be identified.

Tandem High-Pressure Crystallography-Optical Spectroscopy Unpacks Noncovalent Interactions of Piezochromic Fluorescent Molecular Rotors.

To develop luminescent molecular materials with predictable and stimuli-responsive emission, it is necessary to correlate changes in their geometries, packing structures, and noncovalent interactions with the associated changes in their optical properties. Here, we demonstrate that high-pressure single-crystal X-ray diffraction can be combined with high-pressure UV-visible absorption and fluorescence emission spectroscopies to elucidate how subtle changes in structure influence optical outputs. A piezochromic aggregation-induced emitter, sym-heptaphenylcycloheptatriene (Ph7C7H), displays bathochromic shifts in its absorption and emission spectra at high pressure. Parallel X-ray measurements identify the pressure-induced changes in specific phenyl-phenyl interactions responsible for the piezochromism. Pairs of phenyl rings from neighboring molecules approach the geometry of a stable benzene dimer, while conformational changes alter intramolecular phenyl-phenyl interactions correlated with a relaxed excited state. This tandem crystallographic and spectroscopic analysis provides insights into how subtle structural changes relate to the photophysical properties of Ph7C7H and could be applied to a library of similar compounds to provide general structure-property relationships in fluorescent organic molecules with rotor-like geometries.

Fluoride Binding Potential of Selected Phytochemicals: A Pilot Study.

Fluoride (F-) contamination in drinking water is a major global concern. According to several studies, India and China are the most affected by the presence of excess F-. Long-time exposure to F- concentrations above 1.5ppm can lead to hard and soft tissue fluorosis(F- toxicity). There are no effective cure or treatment for fluorosis and the condition is almost irreversible. Considering water to be the prime media through which F- reaches humans, maintaining optimal F- levels in water remains the only possible remedy. F- endemic areas have adapted several conventional defluoridation techniques to resolve the issue. Among these, adsorption with plant compounds is widely used for F- removal. Studies have shown that plant metabolites can ameliorate the toxic effects of F-. Based on this, we attempt to elucidate the potential binding and electrochemical bio-sensing properties of selected phytochemicals towards F-. The focus of the present work is to evaluate the interactions of phytochemicals with F-; for which, the binding studies of phytochemicals with F- have been elaborated by UV-visible spectroscopy and emission techniques. Benesi-Hildebrand's (BH) plot was used to calculate the binding constant (CUR-34.9 × 103 (M-1), QUER - 13 ×103 (M-1),ESC-6.3 × 103 (M-1), FIS - 5.36 ×103 (M-1) and PCA-1.5 × 103 (M-1), and detection limit (CUR - 1.54× 10-7M, QUER - 0.156 × 10-6 M,ESC-0.221 × 10-6 M, FIS - 0.175× 10-6 M,and PCA-5.8 × 10-6M) for the F-:phytochemical mixtures. Further, the binding characteristicswere confirmed using 1H-NMRtitration experiments. Our findings highlight the potential of phytochemicals as effective binding agents for F-, thereby reducing its bioavailability.

PEG functionalized ZnO nanoparticles by fusion of precipitation-cum-hydrothermal method with enhanced photocatalytic activity

In this study, polyethylene glycol (PEG)-aided zinc oxide (ZnO) nanoparticles (NPs) have been synthesized by fusion of precipitation-cum-hydrothermal method. The PEG/ZnO NPs were investigated by x-ray diffraction (XRD), Fourier-transform infrared (FTIR) transformation, UV-visible field emission scanning electron microscope (FESEM), energy dispersive x-ray, high resolution transmission electron microscope (HRTEM), and RAMAN techniques. XRD analysis confirms the formation of the wurtzite phase with a crystallite size of 8 nm of synthesized PEG/ZnO. While FESEM and HRTEM investigations reveal the formation of distinct structural forms, FTIR investigations show interactions between PEG and ZnO. High crystallinity of PEG/ZnO is observed in the selected area electron diffraction pattern. The Brunauer–Emmett–Teller (BET) study revealed that ZnO NPs have a mesoporous structure with a significant specific surface area of 42 m2 g−1. The evaluation of photocatalytic activity of PEG/ZnO-based photocatalyst was carried out via the degradation of typical azo dye (industrial methylene blue (MB) dye) along with total organic carbon (TOC) analysis. The PEG-ZnO (dose 200 mg l−1) was found to be an efficient photocatalyst for the degradation of MB dye. The degradation reaction exhibits pseudo-first-order kinetics. Additionally, TOC removal was monitored, elucidating almost complete mineralization.

Spectrophotometric and Spectrofluorimetric Quantification of Urea via Silver Nanoparticles Prepared by Wet Chemical Method

Silver nanoparticles have been utilized in an easy, sensitive, and effective approach through spectrophotometry and spectrofluorimetry to quantify urea in water samples. Here, 1,3-di-(1H-imidazole-1-yl) -2-propanol (DIPO) was employed to stabilize Ag NPs produced from the reduction of aqueous silver nitrate by sodium borohydride (NaBH<sub>4</sub>). Beer-Lambert's law was applied for determination using the complexation of Ag NPs with urea molecules. The results show urea can be assessed concurrently with good results and percent recoveries. The UV-visible absorbance and fluorescence emission calibration curves were plotted at 445 and 471 nm wavelengths, respectively. Beer-Lambert’s law was obeyed in the 0.1-15 mM concentration range. A linear correlation for both UV-visible spectrophotometry and spectrofluorimetry was obtained on optimum conditions using the suggested methods having a limit of detection (LOD) was found to be 0.897 and 0.048, respectively. The percent recovery ± RSD by the spectrophotometric and spectrofluorimetric method was found to be 88 ± 19.7%, 96.67 ± 21.53%, 130.8 ± 1.33% and 102.3 ± 12.7%, 97.26 ± 5.63%, 111.4 ± 3.8%, respectively. Following a comparison of the obtained data, it may be possible to identify spectroscopic approaches with greater efficacy and efficiency that may be used to determine urea's presence in actual samples of biological and non-biological fluids.

Plasma Generated in Hydrodynamic Cavitation Bubbles for the Preparation of Plasma Activated Water

Objective: In recent years, the medical applications of plasma activated water (PAW) have attracted growing interest. PAW can be prepared using plasma generated by hydrodynamic cavitation bubbles (HCB). To facilitate this application, the current study was performed to investigate the efficiency of plasma generation in HCB. Methods: Based on the plasma generated in HCB, an experimental system has been constructed. We measured the characteristics of the cavitating flow, including pressure, temperature, and water flow rate, and estimated the system and cavitation power consumptions. High-speed images of cavitating flow were obtained to examine the evolution of the cavitation zone. Images of discharge emission at various velocities were captured to identify the location of electrodes. In addition, optical emission spectra were examined to determine the type of reactive species. H2O2 concentration and energy efficiency were measured and analyzed. Results: In this experiment, the system power consumption was 1.2W. The highest cavitation power consumption was 50.4W and increased with the elevation of throat velocities. The processing findings of high-speed images revealed that the cavitation characteristic length was essential for plasma generation and was necessary for establishing the location of electrodes. In addition, the UV-Vis emission spectra of the plasma discharge demonstrated that the hydroxyl radical ·OH was formed in situ and that cavitation increased the yield of ·OH. H2O2 was the principal active component of PAW. Plasma generated in HCB produced H2O2 with a high energy efficiency of 77.0mol/kWh. Conclusion: Plasma generated in HCB may provide a viable and cost-effective alternative method for PAW preparation.

<i>In situ</i> study of light emission from SiO<sub>2</sub> irradiated by 645 MeV Xe<sup>35+</sup> ions

Silicon dioxide (SiO<sub>2</sub>) is an important component of nuclear reactor optical fiber and is also a candidate material for wast solidification. Owing to its special physical and chemical characteristics, it is used in many different technology fields like optics, electronics, energy orspace. Swift heavy ion irradiation can modify the crystal structure and optical property of optical material SiO<sub>2</sub>. Swift heavy ions deposit their energy mainly by inelastic interaction. Highly ionized lattice atoms may be formed along the trajectory, and a fraction of their electrical energy can be converted directly into the kinetic energy of the ions. The irradiation experiment is performed with Xe<sup>q+</sup> ions at the irradiation terminal of the sector-focused cyclotron at heavy-ion research facility in Lanzhou (HIRFL). The on-line spectral measurement experiment is carried out during irradiation. In the darkroom, the UV-visible light emission from the target is focused into optical fiber by a collimating lens, and then is analyzed with the Sp-2558 spectrometer equipped with a 1200 g/mm optical grating blazed at 500 nm. In the present work, SiO<sub>2</sub> single crystals are irradiated with 93–609 MeV Xe<sup>q+</sup> ions with a dose in a range of 1×10<sup>11</sup>–3×10<sup>11</sup> ions/cm<sup>2</sup>. During irradiation, the emission spectra, in a range of 200–800 nm, from SiO<sub>2</sub> irradiated by 93, 245, 425 and 609 MeV Xe<sup>q+</sup> ions, are obtained. Two emission bands centered at 461 and 631 nm are observed. These emission bands are produced by Frenkel exciton radiation de-excitation and their intensities are closely related to the irradiated ion energy and radiation dose. The results show that the light intensity increases with the electron energy loss index increasing. And owing to crystal damage caused by ion irradiation, the intensity of emission spectrum decreases with the augment of irradiation dose. Ion loses its energy throughout the ion track via Sn and Se interacting with target atoms and electrons respectively, and the energy lost by the ion is estimated by using SRIM code. The SRIM simulated ion ranges and recoil atom distribution, target ionization (energy loss to target electrons), damage production in SiO<sub>2</sub> are presented. Based on the energy deposition process, the emission bands related to the crystal structure itself are discussed. It indicates that electron energy loss plays a leading role in the process of light emission. In-situ measurement of the optical emission is of great significance in studying the irradiation modification and can help to understand the process of crystal damage caused by ion irradiation.

Characterization of Binding Properties of Cr(Phen)3 3+ and Ru(Phen)3 2+ Complexes with Human Lactoferrin.

This work presents research about [Cr(phen)3 ]3+ and [Ru(phen)3 ]2+ interaction with human lactoferrin (HLf), a key carrier protein of ferric cations. The photochemical and photophysical properties of [Cr(phen)3 ]3+ and [Ru(phen)3 ]2+ have been widely studied in the last decades due to their potential use as photosensitizers in photodynamic therapy (PDT). The behavior between the complexes and the protein was studied employing UV-visible absorption, fluorescence emission and circular dichroism spectroscopic techniques. It was found that both complexes bind to HLf with a large binding constant (Kb ): 9.46 × 104 for the chromium complex and 4.16 × 104 for the ruthenium one at 299 K. Thermodynamic parameters were obtained from the Van't Hoff equation. Analyses of entropy (ΔS), enthalpy (ΔH) and free energy changes (ΔG) indicate that these complexes bind to HLf because of entropy-driven processes and electrostatic interactions. According to circular dichroism experiments, no conformational changes have been observed in the secondary and tertiary structure of the protein in the presence of any of the studied complexes. These experimental results suggest that [Cr(phen)3 ]3+ and [Ru(phen)3 ]2+ bind to HLf, indicating that this protein could act as a carrier of these complexes in further applications.

Effect of Hydroxyl Group on Photo-Physical Properties and Dipole Moments of Fluorescent Dyes: An Experimental and Computational Approach.

In this work, structurally similar, (E)-N'-(2-hydroxybenzylidene)-3,5-di-tert-butyl-2-hydroxybenzohydrazide (A) and (E)-N'-(2-4-dihydroxybenzylidene)-3,5-di-tert-butyl-2-hydroxybenzohydrazide (A-OH) dyes dissolved in general solvents have been studied to explore photo-physical properties, employing solvatochromic shift method, thereby determining their dipole moments in the ground (μg) and excited (μe) states. The molecule A shows a bathochromic shift of fluorescence emission maxima in aprotic solvents whereas a hypsochromic shift in protic solvents. Interestingly, A-OH follows a hypsochromic shift in both protic and aprotic solvents with increasing solvent polarity. The effect of hydroxyl substituent on UV-Visible absorption, fluorescence emission, and dipole moment of the titled organic molecules was explained. Theoretical methods such as Bilot-Kawski method for determination of μg and μe and Bakshiev, Kawski-Chamma-Viallet, Lippert-Mataga equations for μe, and Reichardt method for the difference between μg and μe were employed. It is observed that μe is higher than that of μg for both the molecules, and interestingly, upon substituting an additional hydroxyl group the value of μg has increased while μe is decreased. The DFT calculations have been performed to support experimental results by employing DFT/B3LYP/6-311G + (d) and TD-DFT/B3LYP/6-311G + (d) method using Gaussian09 software. The electrophilic and nucleophilic sites on the molecules were studied with the help of MEP. The NBO analysis results show that the interaction N24 (σ) → C22-O23 (π*) is found to be stronger in both the molecules with energy 68.90kJ/mol and the effect of hydroxyl group is also discussed on the basis of HOMO and LUMO.

Photophysical properties of novel tetra-3-substituted phthalocyanines of Zn(II), Cu(II) and Pd(II)

Newly metallo-phthalocyanines substituted MPc1 of zinc, copper, and palladium, bearing 3-((2,6-di(pyridin-3-yl)-phenoxy) substituent at [Formula: see text]-position (non-peripheral) were synthesized and characterized by common spectroscopic methods such as 1H-NMR, IR-FTR, MS, UV-Visible and florescence emission. Flowing several synthetic routes, the yield was increased in the series of metals: from CuPc1, PdPc1, to ZnPc1 and from ZnPc1, to ZnPc2, to ZnPc3, compared with their analogies in the literature. Afterwards, the effect of changing metals and substituents’ positions increased the Q-band value and florescence emission from PdPc1 to CuPc1 to ZnPc1 and from ZnPc2 ([Formula: see text]-position) to ZnPc3 (octa-position), to ZnPc1([Formula: see text]-position) and from cationic phthalocyanines ZnPc 2Me to ZnPc 3Me to ZnPc 1Me. The study of aggregation tendance in DMSO was examined in different concentrations to confirm that there was no aggregation appearance.

Photophysical Properties of Linear, Net-structured and Branched Polybenzimidazoles.

Polybenzimidazoles with three different network structures are synthesized by condensation polymerization between the conventional monomer 3,3'-Diaminobenzidine and three different acid monomers. The synthesised polymer networks are characterized using several characterization techniques such as FT-IR, powder XRD, HR-SEM and TG-DTA analyses. The polybenzimidazoles are amorphous in nature with excellent thermal stability up to 450 ºC. The photophysical properties of polybenzimidazoles are studied using UV-visible absorption and Emission spectral techniques. Further, the excited state photoluminescence decay time measurement shows a functional group dependant decay behaviour. All the three polymers display narrow optical band gap energy and could be applied as a material for solar energy conversion and semiconductors.

Synthesis and characterization of surface-modified ultrafine titanium dioxide nanoparticles with an antioxidant functionalized biopolymer as a therapeutic agent: Anticancer and antimicrobial evaluation

Surface modified biodegradable protein-based nanoparticles have great potential in pharmaceutical applications. In the present study, we discuss the surface engineering of titanium dioxide nanoparticles (TiO2 NPs) with alpha-lipoic acid (ALA) functionalized bovine serum albumin (BSA) conjugate as a biocompatible therapeutic system. Sol-gel method is used to synthesize TiO2 NPs, which is characterized using ultraviolet (UV)/visible, Fourier transform infrared (FT-IR), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). BSA was functionalized with antioxidant ALA by Steglich esterification, and TiO2 NPs were loaded into this synthesized BSA-ALA conjugate. The finally developed product was studied using various characterization methods like UV-Visible, FT-IR, XRD, SEM-EDX, TEM, TG-DTG, DSC and fluorescence emission analysis. In vitro cytotoxicity of this system was examined by applying the trypan blue exclusion method, and antimicrobial analysis was implemented by well diffusion method against antibiotic-resistant bacterial and fungal strains.

Plant tissue characteristics of Miscanthus x giganteus

As part of a study identifying relationships between environmental variables and insect distributions within a bioenergy crop, giant miscanthus (Miscanthus x giganteus) samples were collected in October 2016 at 33 locations within a field in southeast Georgia, USA. At each location, one plant sample was collected every 3 to 4 m along a 15 m transect, resulting in 5 replicates per sampling location. The plant samples were separated into leaves and stems, dried, and ground. The chemical composition of the ground material was assessed by measuring total carbon and nitrogen, total macro- and micronutrients (aluminum, arsenic, boron, calcium, cadmium, cobalt, chromium, copper, iron, potassium, magnesium, manganese, molybdenum, sodium, nickel, phosphorus, lead, sulfur, selenium, silicon, titanium, vanadium, and zinc) using Inductively Coupled Plasma with Optical Emission Spectroscopy (ICP-OES), and optical characteristics of the water extractable organic matter (WEOM) using UV-Visible and Fluorescence Excitation Emission Matrix (EEM) spectroscopy. This dataset will be useful to identify relationships between the chemical composition of giant miscanthus tissues and pest distributions within a bioenergy crop field.

Wavelength effect on polymer photooxidation under LED weathering conditions

This paper is devoted to the investigation of the photooxidation of poly(N-vinylcarbazole (PVK) and polyethylene (LDPE) by exposure to λ ≥ 300 nm polychromatic light (SEPAP 12.24) or UV light produced by a new setup equipped with LEDs emitting at 365 nm (LED 365), both at a temperature of 60°C. Photooxidation was studied by infrared and UV-visible spectroscopies and emission spectroscopy in the case of PVK. The mechanisms by which the oxidation products were formed in both polymers were recalled. Depending on the conditions of ageing, i.e., polychromatic light or exposure to LED 365, the same oxidation products were obtained but with different rates and different relative amounts. This result reflected the influence of the wavelengths on the mechanisms. In the case of PVK, the formation of oxidation photoproducts and yellowing were not impacted, but the kinetics of the decrease in excimer fluorescence, which is linked to the crosslinking of the polymer, were dramatically modified. In the case of LDPE, wavelength effects on the photolysis of ketones by Norrish reactions were observed. As a consequence, irradiations with the LED 365 setup could not be claimed to be representative of polychromatic irradiations because the shortest wavelengths (300 nm < λ < 350 nm) were missing and could not reproduce natural outdoor conditions of weathering.