UV-vis Absorption Spectroscopy Research Articles

Mechanisms of controlled stabilizer-free synthesis of gold nanoparticles in liquid aerosol containing plasma.

The interaction between low-temperature plasma and liquid enables highly reactive solution phase chemistry and fast reaction kinetics. In this work, we demonstrate the rapid synthesis of stabilizer-free, spherical and crystalline gold nanoparticles (AuNP). More than 70% of gold ion complex (AuCl- 4) conversion is achieved within a droplet residence time in the plasma of ∼10 ms. The average size of the AuNPs increases with an increase in the droplet residence time and the particle synthesis showed a power threshold effect suggesting the applicability of the classical nucleation theory. Leveraging UV-vis absorption and emission spectroscopy, and nanoparticle size distributions obtained from TEM measurements, we showed that the AuCl- 4 conversion exceeded by 250 times the maximum faradaic efficiency. We identified important roles of both short-lived reducing species including solvated electrons and possibly vacuum ultraviolet (VUV) photons, and long-lived species, H2O2, in the reduction of AuCl- 4. A quantitative investigation was performed by a 1-D reaction-diffusion model which includes transport, plasma-enabled interfacial reduction of AuCl- 4, classical nucleation, monomer absorption and autocatalytic surface growth enabled by H2O2. The model shows good agreement with the experimental results. The timescale analysis of the simulation revealed that nucleation is enabled by fast reduction of gold ions, and autocatalytic growth mainly determines the particle size and is responsible for the majority of the ion precursor conversion while also explaining the excessively large faradaic efficiency found experimentally.

Synthesis, photo-physicochemical and biological properties of novel tetrahydropyrimidone-substituted metallo-phthalocyanines.

In this study, new peripherally substituted symmetric zinc and magnesium phthalocyanines (4 and 5) were successfully prepared by cyclotetramerization of the tetrahydropyrimidone (THPM)-linked phthalonitrile 3. The identity of the compounds were confirmed primarily through spectroscopic analysis including NMR, FT-IR, UV-Vis and MALDI-TOF mass spectroscopy. The photophysical and photochemical properties of the synthesized phthalocyanines (Pcs) were examined using UV-Vis absorption and fluorescence emission spectroscopy techniques. The quantum yields of singlet oxygen were found to be 0.50 and 0.33 for compounds 4 and 5 in DMSO, respectively. In addition to photo-physicochemical properties, the enhanced biological activities of compounds 4 and 5 were investigated using a range of biological assays, namely, antibiofilm, microbial cell viability, antioxidant, DNA cleavage, antimicrobial and photodynamic antimicrobial assays. The maximum DPPH inhibition of 4 and 5 was detected as 40.46% and 25.76% at 100 mg L-1, respectively. Fragmentation of the DNA molecule was observed at concentrations of 25 mg L-1, 50 mg L-1 and 100 mg L-1 for 4 and 5. Additionally, effective inhibition of microbial cell viability was observed with the targeted Pcs. The antibiofilm properties of these compounds were found to be concentration-dependent. The biofilm inhibition activities of 4 and 5 were found to be 96.01% and 92.04% for S. aureus, while they were 95.42% and 91.27%, for P. aeruginosa, respectively. The antimicrobial activities of 4 and 5 on different microorganisms were evaluated using the microdilution assay. In the case of photodynamic antimicrobial treatment, the newly synthesized Pcs showed more effective antimicrobial inhibition compared to the control. These findings suggest that compounds 4 and 5 can be used as promising photodynamic antimicrobial agents for the treatment of many diseases, particularly infectious diseases.

The prospect of spray pyrolyzed pure, Mn-doped, and Zn-doped nickel oxide thin films as TCO material

Nickel Oxide films with Manganese (Mn) and Zinc (Zn) doping (NiO, Ni1-xMnxO, and Ni1-xZnxO; where x = 0, 0.02, 0.04, and 0.06) were fabricated using the spray pyrolysis technique on the glass substrates at 400 °C (673K) temperature. The XRD spectra revealed a polycrystalline nature of the films with cubic crystal structure and a favored growth orientation towards the (111) plane. The SEM micrographs revealed a smooth, homogeneous, and uniform surface, while the EDS spectra confirmed the presence of Ni, O, Zn, and Mn elements in the films. Optical analysis using UV–visible absorption spectroscopy demonstrated high transparency of the films in the visible region (400 nm–900 nm), and the transparency increased with higher Zn doping, reaching ∼85 % in Ni0.94Zn0.06O films. Conversely, Ni1-xMnxO films show a slight transmission decline with increasing Mn doping concentrations. The sheet resistance of the films was found to be decreased for low-concentration doping and again began to increase for highly doped Ni0.94Zn0.06O and Ni0.94Mn0.06O films. Among all the films, Ni0.98Zn0.02O exhibited the maximum figure of merit, showing the prospect for optoelectronic applications.

Viologen-based supramolecular crystal gels: gelation kinetics and sensitivity to temperature.

Supramolecular crystal gels, a subset of molecular gels, are formed through the self-assembly of low molecular weight gelators into interconnecting crystalline fibers, creating a three-dimensional soft solid network. This study focuses on the formation and properties of viologen-based supramolecular crystalline gels. It aims to answer key questions about the tunability of network properties and the origin of these properties through in-depth analyses of the gelation kinetics triggered by thermal quenching. Experimental investigations, including UV-Vis absorption spectroscopy, rheology, microscopy and scattering measurements, contribute to a comprehensive and self-consistent understanding of the system kinetics. We confirm that viologen-based gelators crystallize by forming nanometer radius hollow tubes that assemble into micro to millimetric spherulites. We then show that crystallization follows the Avrami theory and is based on pre-existing nuclei. We also establish that the growth is interface-controlled, leading the hollow tubes to branch into spherulites with fractal structures. Finally, we demonstrate that the gel properties can be tuned depending on the quenching temperature. Lowering the temperature results in the formation of denser and smaller spherulites. In contrast, the gel's elasticity is not significantly affected by the quench temperature, leading us to hypothesize that the densification of spherulites occurs at the expense of connectivity between spherulites.

The TR-icOS setup at the ESRF: time-resolved microsecond UV-Vis absorption spectroscopy on protein crystals.

The technique of time-resolved macromolecular crystallography (TR-MX) has recently been rejuvenated at synchrotrons, resulting in the design of dedicated beamlines. Using pump-probe schemes, this should make the mechanistic study of photoactive proteins and other suitable systems possible with time resolutions down to microseconds. In order to identify relevant time delays, time-resolved spectroscopic experiments directly performed on protein crystals are often desirable. To this end, an instrument has been built at the icOS Lab (in crystallo Optical Spectroscopy Laboratory) at the European Synchrotron Radiation Facility using reflective focusing objectives with a tuneable nanosecond laser as a pump and a microsecond xenon flash lamp as a probe, called the TR-icOS (time-resolved icOS) setup. Using this instrument, pump-probe spectra can rapidly be recorded from single crystals with time delays ranging from a few microseconds to seconds and beyond. This can be repeated at various laser pulse energies to track the potential presence of artefacts arising from two-photon absorption, which amounts to a power titration of a photoreaction. This approach has been applied to monitor the rise and decay of the M state in the photocycle of crystallized bacteriorhodopsin and showed that the photocycle is increasingly altered with laser pulses of peak fluence greater than 100 mJ cm-2, providing experimental laser and delay parameters for a successful TR-MX experiment.

Green Synthesis and Characterization of Hydrozincite Nanoparticles from Wild Passion Fruit

Abstract: Green synthesis of nano particles involves the use of whole plant or parts of plant for the bioreduction of metal ions into their elemental form. Hydrozincite nano particles were synthesized using the wild passion fruit. The fruit has got so many health benefits. The synthesized nano particles were characterized by X-Ray diffraction(XRD), Fourier Transform Infra-Red spectroscopy(FT-IR), UV-Vis absorption spectroscopy(UV), Scanning Electron Microscope(SEM) and Energy Dispersive X-Ray Diffraction(EDX). Using XRD the average particle size was found to be 14.032nm. The functional groups of the prepared sample were identified using FT-IR analysis. From UV the absorption peak was noticed at 302.199 nm which confirms the particle was in nano range. The surface morphology of the synthesized particles was noticied as bread spongy from the SEM analysis. The chemical compounds in the nano particles were identified using EDX analysis. Anti-microbial resistance is one of the greatest challenges to global health. The prepared nano particle shows a good effect for both gram-positive and gramnegative anti-bacterial activity.

Treatment of Automotive Paint Wastewater: Photocatalytic degradation of methylene blue using semi-conductive ZrO2

Addressing water pollution, particularly in the automotive industry's painting processes, is vital due to its significant environmental impact, and the use of photocatalysis, an environmentally friendly and energy-efficient advanced oxidation method, holds promise for removing non-biodegradable organic dyes from wastewater. In this study, the use of semiconductor ZrO2 nanoparticles in the photocatalytic degradation of pollutants in wastewater under UV light was investigated. Zeta potential, Brunauer–Emmett–Teller (BET) surface area and UV-Vis absorption spectroscopy analyses were performed on the ZrO2 nanoparticle synthesized under optimized experimental conditions. ZrO2 nanoparticles synthesized under the optimized experimental conditions exhibited a high specific surface area (51.793 m2/g). ZrO2 nanoparticles had strong absorption in the visible light region, and the energy band gap was estimated to be approximately 3.062 eV. The photocatalytic activity was evaluated by the degradation of methylene blue under UV light (366 nm). The effects of parameters such as the amount of catalyst, concentration and pH of the dye solution, the wavelength of the UV light source used (366 and 254 nm) and the type of test environment on the removal efficiency of methylene blue were investigated. ZrO2 nanoparticles showed a high degradation efficiency of 91% in a strong alkaline environment, which may be the result of the facilitated formation of –OH radicals due to the increased concentration of hydroxyl ions.

Tailoring the temperature coefficient of resistance of flame-formed carbon nanoparticle thin films by electric field-assisted deposition

The electric-field assisted deposition is successfully proposed as a method for the manufacturing of carbon nanostructured films with tunable properties, benefiting from the superimposition of electric fields on the thermophoretic deposition. Morphology, optical, and thermo-resistive properties of the carbon nanoparticle (CNP) films have been studied by UV–vis Absorption Spectroscopy, Scanning Electron Microscopy, Atomic Force Microscopy, and Current-Voltage analysis. In comparison to thermophoresis alone, the introduction of an electric field results in a six-fold increase in the deposition rate characterized by a non-linear film growth influenced by a three-fold augmentation in surface roughness and polarization effects. Notably, the surface morphology of the CNP films undergoes modification, exhibiting larger grains and a reduced optical band gap energy. Moreover, while maintaining a non-ohmic behaviour, the electric field plays a crucial role in increasing by about two orders of magnitude the electrical conductance of CNP films at ambient temperature. This effect is accompanied by a decrease in temperature sensitivity, attributed to the low and nearly temperature-independent activation energy for the tunneling of electrons in the percolative network. In summary, electric-field assisted deposition is a promising approach to tailor the thermal response of CNP films, which could be beneficial for the development of next-generation sensors.

Photophysical, thermal, and DFT studies on a tetraaryl-azadipyrromethene ligand and its zinc(II) complex.

An azadipyrromethene ligand (H1) and homoleptic zinc(II) (H1-Zn) complex were synthesized. The resulting structures were elucidated by NMR, FTIR, and HRMS techniques. The photophysical properties and effects of complexing the zinc(II) atom to azadipyrromethene ligands in solution were studied by means of UV-Vis absorption and fluorescence spectroscopy. Experimental findings were elucidated using density functional theory computations and interfragment charge transfer (IFCT) and electron-hole analyses. The fluorescence features were found to be negligible. The ligand molecule decayed at a rate of 3% while the complex decayed at 2% upon photoirradiation based on photostability experiments. The singlet oxygen quantum yields of the ligand and complex were calculated as 0.127 and 0.233, respectively, signifying low photodynamic activity. The charge transfer transitions were determined between reciprocal ligands responsible for the red shift of the main absorption band by IFCT and electron-hole analysis. Compounds in an inert N2 atmosphere demonstrated high thermal stability. Although the thermogravimetric analysis (TGA) and derivative thermogravimetry curves of the complexes were similar, zinc(II) coordination and homoleptic complex formation reduced the degradation temperatures. These findings suggest that azadipyrromethene and the Zn(II) class of chromophores have beneficial features for use in the development of novel photo- and thermostable materials that combine charge transfer with low energy in the visible and near infrared regions.

Spectroscopic inspection, DFT analysis, biological evaluation and molecular docking studies of new 2-(phenylamino)acetohydrazide hydrazone based- transition metal complexes

The binuclear Pd(II) and mononuclear Zn(II), Ru(III) and Pt(IV) chelates were synthesized based on new hydrazone ligand derived from 2-(phenylamino)acetohydrazide and 3-Acetyl-2-hydroxy-6-methyl-4H-pyran-4-one (dehydroacetic acid DHA) (H2L). Variable characterization tools were used to confirm the exact structures. Spectral data show that (H2L) ligand acts as monobasic tridentate with ONO donor form. UV–Vis absorption spectroscopy and magnetic moment measurements demonstrated that the Ru(III) and Pt(IV) chelates possess an octahedral environment while Zn(II) and Pd(II) chelates possess square planar environment. The geometry of each complex was optimized using DFT calculation. The stability of the compounds was elucidated by the TGA technique. Antimicrobial activity of the compounds was evaluated and the results showed that the complexes demonstrated superior inhibitory action to ligand and display excellent antimicrobial activities against the tested microorganisms. Zn(II) mononuclear chelate showed the greatest effect against both types of bacterial strains. Antiviral activity was evaluated against Coxsackie virus (Cox B4), Herpes simplex (HSV1) and Hepatitis AVirus(HAV). The binuclear Pd(II) chelate revealed high activity against the three studied viruses while the mononuclear Ru(III) chelate revealed similar activity against the two types only. The cytotoxicity results supported the greatest effect of Zn(II) and Pd(II) against MCF-7 type. Zn(II) chelate revealed the best result against Hep-G2 type. Finally, we can conclude that binuclear Pd(II) chelate was active against all studied disease types, while not all mononuclear chelates are active. The microbial and tumor inhibition activity was compared with the theoretical molecular docking results with the specification of the active species in the selected proteins.

Optimizing the Synthesis of Folic Acid Conjugated Silver Nanoparticles by Box-Behnken Design to Target Breast Cancer Cells

In this study, the synthesis of folic acid conjugated silver nanoparticles (FA&AgNPs) was optimized. FA&AgNPs were synthesized by reduction of silver nitrate with folic acid, which is widely used to target folate receptors in cancer cells. Five independent variables (stirring speed, AgNO3 concentration, folic acid concentration, AgNO3 volume/folic acid volume, and temperature) that were effective on silver nanoparticle synthesis were determined. Based on the independent variables, an experimental plan consisting of 46 experiments was created using the Box-Behnken design (BBD). Nanoparticle formation, physical color change, UV-Vis absorption spectroscopy, Dynamic Light Scattering (DLS) analysis, and Fourier Transform Infrared (FTIR) analysis were evaluated. The mean particle size and zeta potential of FA&AgNPs produced under optimized conditions were measured as 207±4.3 nm and -51.6 mV±2.5, respectively. Cytotoxicity tests were performed to evaluate the anticancer activity of FA&AgNPs in breast cancer cell lines. The IC50 values for MDA-MB-231 breast cancer cells at 24 hours and 48 hours were 20.0 µg/mL and 16.9 µg/mL, respectively, and 26.3 µg/mL and 31.5 µg/mL for MCF-7 cells. The findings indicated that FA&AgNPs have the potential to be an effective anticancer agent in breast cancer cells.

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.

Yellow-emitting carbon dots as fluorescent sensors for the rapid determination of curcumin

The non-standard use of curcumin could cause some adverse drug reactions, such as diarrhea, nausea and skin allergies. Thus, the curcumin determination was fundamental to disease treatment and prevention. Herein, a facile and efficient fluorescent probe was developed based on carbon dots, which was prepared through hydrothermal method (o-phenylenediamine and N-isopropylacrylamide as the reaction raw materials). Characteristics of the as-fabricated carbon dots (NCDs) were studied through some analysis techniques, such as UV–vis absorption spectroscopy, transmission electron microscopy, Fourier transform infrared instrument, X-ray photoelectron spectroscopy and fluorescence spectrophotometer. Fluorescence quenching phenomenon could be observed after addition of curcumin. This as-prepared fluorescent probe displayed a significant response for the determination of curcumin with a satisfactorily lower detection limit of 0.017 μM and a considerable linear range of 0.5–50 μM compared to reported literatures. Because of the preeminent repeatability and anti-jamming capability, the as-developed CDs suggested mighty potentiality for actual applications of curcumin detection in real samples and temperature sensing.

Characterization of nanoscale morphology and mechanical properties of conjugated polymer thin films dynamically exposed to a secondary solvent

Solution processing techniques are often used to enhance intra and interchain order in semiconducting conjugated polymer thin films used in the active layer of organic optoelectronic devices. While there has been extensive research into the impact of solution processing on the local structural and electronic properties of these films, the nanomechanical properties of the films are less well understood and are challenging to characterize. We investigate the nanomechanical properties of conjugated polymer thin films arising from solution processing techniques. Our study relies on dynamic secondary solvent dripping to induce subtle changes to the film morphology. We examine thin films of P3HT, PCDTBT, PTB7, and PBDB-T-SF conjugated polymers, commonly used in organic photovoltaics, with the bimodal amplitude modulation-frequency modulation (AM-FM) imaging mode of the atomic force microscopy (AFM) viscoelastic method to probe their local physical and mechanical properties. We find that Young's Modulus data measured by AM-FM AFM can detect additional changes in film properties not discernible by other commonly used bulk thin-film characterization techniques. For PBDB-T-SF, we detect an increase in molecular order that is not noticable by UV–visible absorption spectroscopy, X-ray diffraction or nanoindentation. PCDTBT, the most amorphous of the polymers studied, shows no changes in absorption or X-ray diffraction data, yet clear changes in Young's Modulus were detected by AFM. On the other hand, increases in P3HT order that occurred due to dynamic secondary solvent dripping are detected in both the bulk and AFM measurements. Our study demonstrates the applicability of nanomechanical measurements for characterizing local structural variations in conjugated polymer films. This work is relevant to ongoing efforts to control and understand the complex structure-property-processing relationships of conjugated polymer thin films.

Chalcone derivatives disrupt cell membrane integrity of Saccharomyces cerevisiae cells and alter their biochemical composition.

Fungal infections can be serious or life threatening in severe cases, and the need to discover and find novel antifungal agents persists. Chalcones are plant-derived aromatic compounds that have been appealing synthons for pharmaceutical industry as they have good anticancer, antibacterial, antifungal and anti-inflammatory properties. Although there are few structure-activity relationship studies on chalcones, studies that link the structural features of these compounds to their mode of action are scant. Thus, in this study, we aim to clarify the relationship between chalcone derivatives and their cellular target within the yeast cell Saccharomyces cerevisiae. We observed that some chalcone compounds lead to disruption of cell membrane and cause ion leakage out of the cell. Moreover, chalcones alter the biochemical composition of yeast cells detectable by FTIR spectroscopy and bind to the DNA as shown by our titration experiments based on UV-Vis absorbance spectroscopy. Thus, their interaction with the DNA may be the major impact of these compounds on yeast cells.

Revisiting Open Circuit Corrosion of Cr in Unpurified Molten FLiNaK Salts with a Multi-Modal Approach

Corrosion and mitigation of environmental degradation of structural materials in high-temperature Gen IV molten salt reactors, are critical issues. However, any corrosion studies have historically been forensic post-test examinations and materials development has occurred mainly by trial and error until recently. Meanwhile, a fundamental understanding can only be achieved by recognizing how the corrosion system of model materials in molten fluoride salts evolves as a function of time. A number of in-situ spectroscopy techniques to identify corrosion product compositions in molten salts have been suggested in recent years. Raman, high-temperature UV-Vis absorption spectroscopy, and X-ray absorption spectroscopy are a few of them [1,2]. These techniques' major limitations include the fact that they are mainly qualitative, and complex hardware requiring a beam focusing inside the glove box is needed. At the same time, electrochemical techniques have been presented which can provide the information on behavior of both metal and its corrosion product in the continuously evolving corrosion system in molten salts. However, use of single isolated methods renders it difficult to obtain mechanistic information on instantaneous, time-dependent processes and phenomena during corrosion. These are needs gaps opportunities. In this work we present a detailed electrochemical analysis of the corrosion of polycrystalline chromium at 600°C in FLiNaK over 50 h including an electrochemical analysis of in-situ near-instantaneous corrosion rates corroborated with other methods.A variety of corroborating methods including (1) in-situ electrochemical diagnostic techniques, (2) static immersion exposure with gravimetric and SEM analysis, (3) electrochemical impedance spectroscopy, (4) XRD, (5) ICP-OES, was utilized to study the corrosion behavior in unpurified FLiNaK at 600°C. The focus was to evaluate the viability of using an external non-reactive electrode to measure the concentration of corrosion products via redox process analysis in order to determine the corrosion rate during the process of OCP corrosion of Cr in FLiNaK. This work reports the possibility of using of electrochemical techniques such as CV for the instantaneous determination of Cr corrosion rates when Cr is exposed to a 600oC FLiNaK salts for 50 h. It was found that the concentration of dissolved corrosion products, in the more likely possible forms of CrF3 - and CrF6 3- , might be calculated by established analytical approaches to CV analysis such as Berzins-Delahay (soluble/insoluble) and Randles-Ševcik equations (soluble/soluble). The calculated values showed the definite concentration of Cr(II)/Cr(III) corrosion products at the distance of the external electrode (due to the static corrosion conditions). These finding supported by XRD and ICP-OES. A semi-infinite diffusion model was employed in this study to adjust the calculated concentrations assuming a stagnant solution and diffusion based one-dimensional concentration diffusion profile in order to calculated the Cr(III) concentration at a fixed position in the Cr(III) concentration gradient. It was shown that the semi-infinite diffusion model helps correctly describe this profile between 10 and 50 h, based on the geometry of the working electrode and corrosion cell. Based on these results the OCP corrosion rate was interpreted to switch over 50 h from initially charge transfer control Cr(II) oxidation at early times with likely HF and Cr(III) reduction, followed by mass transport control regulated by a salt film and then possible stifling due to depletion of HF and Cr(III) solubility limits.The results of half-cell redox potentials and peak currents pertaining to oxidation/reduction of Cr corrosion products were correlated to the concentrations of particular Cr species and compared with the results of mass loss experiment and ex-situ ICP-OES of post-exposed FLiNaK. The mass loss of the Cr(II)/Cr(III) metal that was approximated by spatially integrating the concentration profiles at a selected time, and the result of Cr mass loss separately obtained from gravimetric measurements showed a reasonable agreement. Furthermore, the rate of accumulation of Cr ions in the residual FLiNaK salt after 50 h of exposure determined by ICP-OES, correlated with the electrochemical CV and EIS analysis. In addition to this, the oxidation and reduction peak potentials pertaining to Cr/CrF3 - and CrF3 -/CrF6 3- redox reactions (measured on Pt wire) were compared with the OCP (measured on Cr) to provide insights on the predominant anodic and cathodic reactions. Acknowledgments This research was supported as part of the fundamental understanding of transport under reactor extremes (FUTURE), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences. Utilization of the Malvern-Panalytical Empyrean diffractometer was supported by Nanoscale Materials Characterization Facility with National Science Foundation under award CHE-2102156. References Y. Liu et al., (2020) Corrosion Science. 169 108636. https://doi.org/10.1016/j.corsci.2020.108636.S. Fayfar, et al., (2022). https://doi.org/10.26434/chemrxiv-2022-3nspm.

Crystal structure, magnetic and optical investigation, Hirshfeld surface analysis, and DFT calculation of new organic-inorganic hybrid (NH3(CH2)2CO2H)2[MnCl4(OH2)2

A novel hybrid material, blending organic and inorganic components (NH3(CH2)2CO2H)2 [MnCl4(OH2)2], has been successfully synthesized and meticulously examined. This intriguing compound crystalizes in monoclinic system, with C2/c space group. The unit cell dimensions are as follows: a = 21.497 (8) Å, b = 7.212 (2) Å, c = 11.149 Å, β = 109.09 (2)°, with a unit cell containing four entities (Z = 4). The asymmetric unit consisted of a combination of one half of ½[Cl4Mn(OH2)2]2- and an organic + NH3(CH2)2CO2H cation. The structural integrity is upheld through an intricate three-dimensional hydrogen network, serving as a stabilizing force for the crystal lattice.Notably, the resolved structure unveils a stratified arrangement along the b-axis, creating distinct layers within the material, separating the organic and inorganic components. The intricate interplay of intermolecular forces, specifically involving H⋅⋅⋅Cl, O⋅⋅⋅O, and H⋅⋅⋅H interactions, has been thoroughly examined using Hirschfeld surface analysis. Furthermore, we employed Density Functional Theory (DFT) calculations to optimize the molecular structure.To gain deeper insights into its properties, we conducted micro-Raman spectroscopy measurements to elucidate the vibration modes exhibited by the compound. Additionally, the material's characteristics were probed using a Vibrating Sample Magnetometer (VSM), the compound exhibits ferromagnetism. The UV–visible absorbance spectroscopy, providing comprehensive information about its optical properties (energy gap is about 4.0 eV).

Synthesis, crystal structure and antitumor activity of trialkyltin (IV) 9,10-anthraquinone-2-carboxylate

Two new anthraquinone-organotin complexes [Ph3Sn(O2CC14H7O2)·MeOH]·MeOH (AQS01) and Cy3Sn(O2CC14H7O2) (AQS02) were synthesized and characterized by elemental analysis, IR, 1H NMR, 13C NMR, 119 Sn NMR, X-ray crystallography and thermo-gravimetric analysis. Incorporation of 9,10-anthraquinone with organotin successfully enhanced its anticancer activity. Interestingly, the anti-proliferative activity of AQS01 against CAL-27 cells in vitro was almost 10-fold that of mitoxantrone and 40-fold that of cisplatin. Flow cytometry showed that AQS01 could induce apoptosis and arrest cell cycle in S phase. UV–visible absorption spectrometry and molecular docking showed that AQS01 can be well embedded in the double helix of DNA. Moreover, AQS01 induced cell death by upregulating the expression level of the DNA damage protein γ-H2AX and activating the mitochondrial apoptotic signaling pathway (Bax/Bcl-2). Therefore, AQS01 can be used as a potential anticancer drug and has potential for further research.

A Diruthenium Metallodrug as a Potent Inhibitor of Amyloid-β Aggregation: Synergism of Mechanisms of Action.

The physical and chemical properties of paddlewheel diruthenium compounds are highly dependent on the nature of the ligands surrounding the bimetallic core. Herein, we compare the ability of two diruthenium compounds, [Ru2Cl(D-p-FPhF)(O2CCH3)3]·H2O (1) (D-p-FPhF- = N,N'-bis(4-fluorophenyl)formamidinate) and K3[Ru2(O2CO)4]·3H2O (2), to act as inhibitors of amyloid aggregation of the Aβ1-42 peptide and its peculiar fragments, Aβ1-16 and Aβ21-40. A wide range of biophysical techniques has been used to determine the inhibition capacity against aggregation and the possible mechanism of action of these compounds (Thioflavin T fluorescence and autofluorescence assays, UV-vis absorption spectroscopy, circular dichroism, nuclear magnetic resonance, mass spectrometry, and electron scanning microscopy). Data show that the most effective inhibitory effect is shown for compound 1. This compound inhibits fiber formation and completely abolishes the cytotoxicity of Aβ1-42. The antiaggregatory capacity of this complex can be explained by a binding mechanism of the dimetallic units to the peptide chain along with π-π interactions between the formamidinate ligand and the aromatic side chains. The results suggest the potential use of paddlewheel diruthenium complexes as neurodrugs and confirm the importance of the steric and charge effects on the properties of diruthenium compounds.

Anthraquinones from the roots of Morinda scabrida Craib exhibit antiproliferative activity against A549 lung cancer cells and antitubulin polymerization

Six anthraquinones were isolated from Morinda scabrida Craib, an unexplored species of Morinda found in the tropical forest of Thailand. All six anthraquinones showed cytotoxicity against A549 lung cancer cells, with the most active compound, nordamnacanthal (MS01), exhibiting the IC50 value of 16.3 ± 2.5 μM. The cytotoxic effect was dose-dependent and led to cell morphological changes characteristic of apoptosis. In addition, flow cytometric analysis showed dose-dependent apoptosis induction and the G2/M phase cell cycle arrest, which was in agreement with the tubulin polymerization inhibitory activity of MS01. Molecular docking analysis illustrated the binding between MS01 and the α/β-tubulin heterodimer at the colchicine binding site, and UV–visible absorption spectroscopy revealed the DNA binding capacity of MS01.