Chlorine Molecules Research Articles

Isolation of Isotrichophycin C and Trichophycins G-I from a Collection of Trichodesmium thiebautii.

The trichophycin family of compounds are chlorinated polyketides first discovered from environmental collections of a bloom-forming Trichodesmium sp. cyanobacterium. In an effort to fully capture the chemical space of this group of metabolites, the utilization of MS/MS-based molecular networking of a Trichodesmium thiebautii extract revealed a metabolome replete with halogenated compounds. Subsequent MS-guided isolation resulted in the characterization of isotrichophycin C and trichophycins G-I (1-4). These new metabolites had intriguing structural variations from those trichophycins previously characterized, which allowed for a comparative study to examine structural features that are associated with toxicity to murine neuroblastoma cells. Additionally, we propose the absolute configuration of the previously characterized trichophycin A (5). Overall, the metabolome of the Trichodesmium bloom is hallmarked by an unprecedented amount of chlorinated molecules, many of which remain to be structurally characterized.

A Porous Organic Polymer Nanotrap for Efficient Extraction of Palladium

AbstractTo offset the environmental impact of platinum‐group element (PGE) mining, recycling techniques are being explored. Porous organic polymers (POPs) have shown significant promise owing to their selectivity and ability to withstand harsh conditions. A series of pyridine‐based POP nanotraps, POP‐Py, POP‐pNH2‐Py, and POP‐oNH2‐Py, have been designed and systematically explored for the capture of palladium, one of the most utilized PGEs. All of the POP nanotraps demonstrated record uptakes and rapid capture, with the amino group shown to be vital in improving performance. Further testing on the POP nanotrap regeneration and selectivity found that POP‐oNH2‐Py outperformed POP‐pNH2‐Py. Single‐crystal X‐ray analysis indicated that POP‐oNH2‐Py provided a stronger complex compared to POP‐pNH2‐Py owing to the intramolecular hydrogen bonding between the amino group and coordinated chlorine molecules. These results demonstrate how slight modifications to adsorbents can maximize their performance.

Design, Synthesis and Photophysical Properties of Chlorinated Small Molecule Non-fullerene Acceptor Based on Benzotriazole for Organic Solar Cells

A novel narrow band-gap chlorinated non-fullerene pentacyclic small molecule acceptor based on benzotriazole with extended absorption edge to the near-infrared (NIR) region, named BZIC-4Cl, was designed and synthesized. Through introducing multi-fused benzotriazole and IC-2Cl, BZIC-4Cl could maintain a lower optical bandgap of 1.38 eV with broad and efficient absorption band from 500 to 950 nm due to increased π−π interactions by the covalently locking thiophene and benzotriazole units. There is a stronger intermolecular charge transfer (ICT) effects between the BZTP core and IC-2Cl end-group. The purity and chemical structure of the acceptor, namely BZIC-4Cl, were tested by 1H NMR. Even though BZIC-4Cl showed slightly poor solubility in certain organic solvents, BZIC-4Cl showed broad and strong absorption with a narrow band-gap which can be matched with polymer donor for efficient organic solar cells.

Performance evaluation of photolytic and electrochemical oxidation processes for enhanced degradation of food dyes laden wastewater.

Wastewater containing dyes is considered as the top-priority pollutant when discharged into the environment. Herein, we report for the applicability of 254 nm ultraviolet light and electrochemical process using a titanium ruthenium oxide anode for the degradation of Allura red and erythrosine dyes. During the photolytic process, 95% of Allura red dye (50 ppm) was removed after 1 h at pH 12 and 35 °C, whereas 90% color removal of erythrosine dye (50 ppm) was achieved after 6 h of treatment at pH 6.0 and 30 °C. On the other hand, 99.60% of Allura red dye (200 ppm) was removed within 5 min by the electrochemical process applying a current density (5 mA cm-2) at pH 5.0 and 0.1 mol L-1 sodium chloride (NaCl) electrolytic medium. Similarly, 99.61% of erythrosine dye (50 ppm) degradation was achieved after 10 min at a current density of 8 mA cm-2, pH 6.0, and 0.1 mol L-1 of NaCl electrolyte. The minimum energy consumption value for Allura red and erythrosine dyes (0.196 and 0.941 kWh m-3, respectively) was calculated at optimum current densities of 5 and 8 mA cm-2. The results demonstrated that the electrochemical process is more efficient at removing dyes in a shorter time than the photolytic process since it generates powerful oxidants like the chlorine molecule, hypochlorous acid, and hypochlorite on the surface of the anode and initiates a chain reaction to oxidize the dyes molecules.

Theoretical analysis of the electrodynamics conditions of photochemical subnano-polishing of a quartz surface in the medium saturated with chlorine molecules

The conditions for the effective photochemical subnano-polishing of quartz surface in the medium saturated with chlorine molecules are considered from an electrodynamics point of view. The light scattering by a quartz surface with sinusoidal profile is analyzed in the result of solving the Helmholtz vector equation for a two-dimensional model by using the finite element approach. It is determined that effective subnano-polishing can be realized when monochromatic light falls normally on a quartz rough surface with sinusoidal profile and the medium around the quartz has a refractive index higher than that of quartz. The communication of separate components of the spatial spectrum of the surface, which has a Gaussian correlation function, with evanescent field parameters near the interface at the initial stage of the surface etching is obtained. It is shown that the surface etching process is nonlinear and unequal for various harmonics of the surface spectrum. At the same time, the electrodynamic solution is essentially independent of the light wavelength.

Photoinduced Production of Chlorine Molecules from Titanium Dioxide Surfaces Containing Chloride

Titanium dioxide (TiO2) is extensively used with the process of urbanization and potentially influences atmospheric chemistry, which is yet unclear. In this work, we demonstrated strong production ...

Adsorption and sequential thermal release of F2 , Cl2 , and Br2 molecules by a porous organic cage material (CC3-R): Molecular dynamics and grand-canonical Monte Carlo simulations.

The adsorption-desorption behavior of fluorine, chlorine, and bromine molecules onto a crystalline porous organic cage, namely CC3-R was calculated at different temperatures using molecular dynamics (MD) and grand-canonical Monte Carlo (GCMC) simulations. Self-diffusion coefficients, radial distribution functions (RDF), and adsorption isotherms were calculated for this purpose. The results show that CC3-R has varied capacities to capture these halogens at ambient and high temperatures, so that the thermal release of fluorine is completed with increasing temperature up to around 70°C and chlorine molecules remain at the CC3-R surface up to 100°C and all bromine molecules are removed from the CC3-R surface at 200°C. We found that bromine self-diffusion was almost independent of temperature between 0 and 100°C in contrast to fluorine and chlorine. Among different diffusion regimes, Knudsen diffusion appears to have an important role in the adsorption of heavy halogens at higher temperatures.

Cyanuric Chloride Containing Chalcones for Possible Breast Cancer Treatment: Synthesis, Antimicrobial and in silico Screening

In this work, we have synthesized efficient antibacterial compounds with anticancer novel molecules based on cyanuric chloride containing chalcone moiety. For this, novel triazine-based organic molecules were synthesized by using cyanuric chloride and 2,4-dichloro-1-ene(4-hydroxyphenyl)phenone and characterized by elemental analysis, FT-IR, NMR and UV-visible spectrometry techniques. Melting point of the molecules were increased with an increase in substitution on cyanuric chloride. The minimum inhibitory concentration (MIC) value of the synthesized compounds showed an excellent result on Gram-negative bacteria with low MIC value of 1.95 μg/mL. Gram-positive bacteria showed little resistance to the synthesized drug. The synthesized compounds were tested for their use as an anticancer drug using in silico screening method. The synthesized compounds in silico molecular docking method using breast cancer protein (BRCA2) confirms that triazine derivative with all three chlorine molecules replaced by 2,4-dichloro-1-ene(4-hydroxyphenyl)phenone showed highest binding energy with the value of -9.1900 Kcal/mol which is in agreement with the observed high MIC value obtained for Gram-negative bacteria. The synthesized molecules preferentially targeted the topoisomerase II of the bacteria. Overall, an efficient antimicrobial drug is synthesized using a simple preparation method.

Bimetallic nanoparticles enhance photoactivity of conjugated photosensitizer

Although photodynamic therapy (PDT) of cancer has been continuously improved, its efficiency is still limited by the high toxicity in the absence of irradiation, aggregation and deactivation by biomolecules of the most common photosensitizers (PS). The association of PS to nanoparticles (NPs) can be a promising tool to overcome these limitations and also to enhance PS tumoral selectivity. In addition, the association of PS to metallic NPs may provide the modulation of PS fluorescence and also the enhancement of PS photoactivity due to the electronic coupling with NPs plasmon effect. Adversely to the innumerous work on the coupling of PS to metallic NPs, the application of bimetallic NPs with this goal has not been explored yet. In this work we investigated the physicochemical properties and cytotoxicity of bimetallic gold-platinum NPs (AuPtNPs) conjugated to a chlorin molecule modified with a thiol group. Additionally, chlorin was coupled to AuNPs for comparative purposes since these have been the most commonly used NPs in PDT. The results showed that both platforms promoted the chlorin solubility in water which is crucial in biological applications. Despite the enhancement of photoactivity promoted by both NPs in comparison with chlorin in solution, chlorin-conjugated with AuPtNPs proved to be a more suitable platform for PDT application, since it showed a lower dark citotoxicity, as well as a higher generation of singlet oxygen and cell internalization compared with chlorin-conjugated AuNPs. It is important to highlight that this is the first work reporting on the enhancement of PS photoactivity by its conjugation to AuPtNPs.

Kinetic Monte Carlo simulations of plasma-surface reactions on heterogeneous surfaces

Reactions of atoms and molecules on chamber walls in contact with low temperature plasmas are important in various technological applications. Plasma-surface interactions are complex and relatively poorly understood. Experiments performed over the last decade by several groups prove that interactions of reactive species with relevant plasma-facing materials are characterized by distributions of adsorption energy and reactivity. In this paper, we develop a kinetic Monte Carlo (KMC) model that can effectively handle chemical kinetics on such heterogenous surfaces. Using this model, we analyse published adsorption-desorption kinetics of chlorine molecules and recombination of oxygen atoms on rotating substrates as a test case for the KMC model.

Synthesis and characterization of binuclear Pt(IV) complexes and tetranuclear mixed valence complexes of Platinum(II)-Platinum(IV)

The binuclear platinum(IV) complexes [NBu4]2[PtIV2(μ-Cl)2(C6F5)4Cl4] (2) and [PtIV2(μ-C8H6N4)2(C6F5)4Cl4] (4) have been synthesized by oxidative addition of chlorine to the binuclear platinum(II) species, but [NBu4]2[PtIV2(μ-OH)2(C6F5)4Cl4] (3) has been synthesized by substitution of the chloride bridges of the platinum(IV) complex. The square planar platinum environments of the Pt(II) starting materials change, as expected, to Pt(IV) octahedral environments with the chloride ligands in trans-position. Only minor changes in the Pt-X (X = Clbridge, OH) interatomic distances are produced because of the oxidation.Depending on the size of the bridging ligands and also probably the anionic character of the diplatinum(IV) complexes, the apical chloride ligands can still act as bridges toward other Pt centers. Thus, the organometallic tetra-nuclear mixed-valence platinum(IV)-platinum(II) complexes with formulas [NBu4]2[{PtIV(μ-X)(C6F5)2}2(μ-Cl)4{PtII(C6F5)2}2] [X = Cl (5), OH (6)] were obtained by reaction of 2 and 3 with cis-[PtII(C6F5)2(thf)2]. The structures of complexes 2, 4 and 6 have been determined by single-crystal X-ray diffraction studies. These crystal structures confirm that the oxidative addition of the chlorine molecule to the platinum(II) complexes 2 and 3 takes place on the axial positions of the platinum centers suggesting a SN2 mechanism. On the other hand, the central core of the anion of 6 has a chair like conformation and the long Pt⋯Pt distances (>3.2 Å) clearly exclude any Pt.···Pt interaction.On the other hand, cis-[(C6F5)2Pt(μ-C8H6N4)Pt(C6F5)2] (1) can be reduced either electrochemically or by reacting with [CoCp2] to the anion [Pt2(μ-C8H6N4)(C6F5)4]- which in the last case, can be isolated as complex 7. According to the EPR studies the anion is not a mixed Pt(II)/Pt(I) compound but a binuclear Pt(II) derivative with the anion [C8H6N4]- as bridging ligand.

CHLORINE GAS SENSING OF SnO2 NANOCLUSTERS AS A FUNCTION OF TEMPERATURE: A DFT STUDY

Density functional theory combined with Gibbs free energy calculations is used to study the sensing behavior of tin dioxide (SnO[Formula: see text] clusters towards chlorine gas molecules. Studied SnO2 clusters’ results show the known property of tin dioxide being an oxygen-deficient semiconductor with the preferred stoichiometry SnO[Formula: see text]. The kind of reactions that result in sensing Cl2 molecules is investigated. These include oxygen replacement, chlorine molecule dissociation and van der Waals attachment. Oxygen replacement shows an increase in energy gap which is the case experimentally. Optimum sensing operating temperature towards Cl2 molecules that results from the intersection of the highest SnO2 adsorption and desorption Gibbs free energy lines is at 275∘C in agreement with the experimentally measured temperature of 260∘C.

The behavior of monocationic chlorin in water and aqueous solutions of non-ionic surfactant Tween 80 and potassium iodide

We have studied the behavior of monocationic chlorin (compound 1) which is considered as an appropriate agent for both antimicrobial and antitumor photodynamic therapy in water, aqueous solutions of KI and non-ionic surfactant Tween 80 with the dynamic light scattering (DLS), UV–Vis and fluorescence spectroscopy techniques. Our results do indicate that the solute reveals a tendency to form aggregates both in diluted (~10−5 mol/kg) and rather concentrated aqueous solutions (~10−3 mol/kg). For diluted aqueous solutions UV–Vis spectra appear to show the appearance of small associates, so-called H-aggregates, whereas for more concentrated solutions the DLS study reveals formation of large aggregates containing both chlorin and water molecules. The addition of surfactants or polymers such as Tween 80 or polyvinylpyrrolidone (PVP) leads to monomerisation of a potential drug for all cases. The spectrophotometric titration of aqueous solutions of compound 1 with Tween 80 demonstrates the strong interaction between surfactant and chlorin molecules, the binding constants and stoichiometry of complex formation being dependent of a solute concentration. The comparison of fluorescence quenching by KI in water and surfactant solutions indicates that solute molecules mainly occupy intermediate positions within Tween 80 micelles nearby the hydrophilic head groups of the surfactant.

Semitransparent fullerene-free polymer solar cell with 44% AVT and 7% efficiency based on a new chlorinated small molecule acceptor

Design and synthesis of low bandgap (LBG) nonfullerene small molecule acceptor (SMA) is of critical importance for realizing high-efficiency semitransparent organic solar cells (ST-OSCs). In this article, we synthesized a LBG new SMA, ID-4Cl, by introducing four chlorine substituents onto the electron-acceptor terminals of IDIC. Its optical bandgap (Egopt) is 1.51 eV, which helps to obtain large short-circuit current-density (Jsc) without scarifying the transmittance in the visible human-eye-sensitive wavelength region (360–700 nm). The optimal opaque device performance was obtained on a relatively thin active layer of 65 nm, showing high power conversion efficiency (PCE) of 10.2%, large Jsc of 18 mA/cm2, high fill factor (FF) of 75%, and open-circuit voltage of 0.77 V. The ST-OSC device fabricated with the structure of ITO/PEDOT:PSS/active layer/PDINO/Au (15 nm) shown a PCE of 6.99% in a small area of 4 mm2 and 1.1% in a large area of 1 cm2 with an AVT (average visible transmittance) of 43.7%, showing potentiality in building integrated photovoltaics.

Investigation of interaction of molecules of inorganic gases with surface of copper-containing polyacrylonitrile

The possibility of adsorption of inorganic gases onto the surface of copper-containing polyacrylonitrile (PAN) films was studied by molecular modeling and quantum chemical calculations. For this, the model of a copper-containing PAN cluster was obtained by these methods, which interacted with the adsorbed gas molecule. Based on the results of the simulation, it was established that when adsorbing gas molecules, intermolecular bonds arise between them and the surface of a cluster of copper-containing PAN. A high probability of adsorption on the surface of copper-containing PAN is manifested in chlorine, hydrogen sulfide, and carbon dioxide molecules. Low probability of adsorption - for molecules of ozone and nitrogen dioxideIntroduction

Survivability of 1‐Chloronapthalene During Simulated Early Diagenesis: Implications for Chlorinated Hydrocarbon Detection on Mars

AbstractAll missions to Mars which have attempted to detect organic molecules have detected simple chlorohydrocarbons, the source of which has yet to be firmly established. This study assessed the likelihood of these chlorinated molecules being indigenous to the sedimentary units in which they were detected or if they were chlorinated during analysis. The survivability of 1‐chloronapthalene was examined via hydrous pyrolysis experiments and its dechlorination kinetics were determined. The results of these experiments were used to model the survivability of this simple chlorohydrocarbon under Mars‐relevant diagenetic conditions using the Sheepbed mudstone unit as a case study. It was found that 1‐chloronapthalene was rapidly dechlorinated under Noachian conditions, and thus, the detected Martian chlorohydrocarbons are unlikely to be ancient and probably formed within the rover's sample handling chain during analysis.

REVERSIBLE CHANGES OF EDGE Π-ELECTRONIC STATES OF MULTILAYER GRAPHENE NANOCLUSTERS UNDER INFLUENCE OF ADSORBED CHLORINE MOLECULES

The reversible decrease in the density of states of current carriers D(EF) at the Fermi level EF for nanographites - structural blocks of activated carbon fibers, at their interaction with adsorbed chlorine molecules, has been found. It has been shown that this effect can be explained by the spin-splitting of edge π-electronic states in nanographites induced by the enhancement of electron-electron interactions due to increase in the D(EF) at partial transfer of the electron density from adsorbent to adsorbate. The revealed irreversible decrease in the concentration of localized spins at nanographite chlorination indicates that the spins of electrons of unsaturated (dangling) σ-orbitals of edge carbon atoms and those of chlorine 3p-orbitals are coupled at this interaction, i.e. the edge covalent compound of nanographite with chlorine forms.

Tumor Size-Dependent Anticancer Efficacy of Chlorin Derivatives for Photodynamic Therapy.

Photodynamic therapy (PDT) with a suitable photosensitizer molecule is a promising anticancer treatment. We evaluated two chlorin molecules as potential photosensitizers, methyl pyropheophorbide a (MPPa) and N-methoxyl purpurinimide (NMPi), against A549 human lung adenocarcinoma cells in vitro as well as in A549 tumor-bearing mice in vivo. Cell viability, microscopy, and fluorescence-activated cell sorting (FACS) analyses were performed for the in vitro studies. MPPa and NMPi showed high phototoxicity in vitro, which was dependent on the concentration of the photosensitizers as well as the light irradiation time. In the animal study, tumor volume change, tumor surface alterations, and hematoxylin & eosin (H&E) and terminal deoxyribonucleotidyl transferse-mediated dUTP nick-end labelling (TUNEL) staining analyses were performed and compared between small (tumor volume of <50 mm3) and large (tumor volume of >50 mm3) size of initial tumors. MPPa and NMPi showed high anticancer efficacy against small-size tumors, indicating that early treatment with PDT is effective. Especially, repeated two times PDT with NMPi allowed almost complete eradication against small-size tumors. However, MPPa and NMPi were not effective against large-size tumors. In conclusion, the two chlorin derivatives, MPPa and NMPi, show good anticancer efficacy as promising photosensitizers for PDT in vitro and in vivo. Moreover, their activity in vivo was significantly dependent on the initial tumor size in mice, which confirms the importance of early cancer treatment.

Properties and Potential Applications of Quasi-Two-Dimensional Molybdenum Disulfide for Nanoelectronic Elements

Currently, the prospects for replacing traditional materials with quasi-two-dimensional compounds based on transition metal dichalcogenides are actively being studied. The quasi-two-dimensional molybdenum disulfide MoS2, a semiconductor with a finite band gap, can be used either as a standalone material or as a part of layered heterostructures. When creating nanosized electronics elements based on such ultrathin materials, the application of an atomic layer etching technology is of key importance. In this paper, a brief description of the properties of MoS2 monolayers in comparison with graphene and the monolayers of hexagonal boron nitride is considered. On the basis of the results of computer simulation by means of a DFT (density functional theory) method, effects caused in the MoS2 monolayer by chlorine atoms and molecules widely used in the state-of-the-art of atomic layer etching applied to silicon materials are demonstrated.

Radiation induced in-situ cationic polymerization of polystyrene organogel for selective absorption of cholorophenols from petrochemical wastewater

A new in-situ cationic polymerization was performed to synthesize a cross-linked (91%) polystyrene (PS) organogel through tetrachloroethylene radiolysis assisted by 60Co gamma rays. Hoernschemeyer diagram and swelling capacity test show a better selectivity of PS organogel to chlorinated molecules compared to ester, hydrocarbons and alcohols organic molecules by 80–184 folds. Response surface modeling (RSM) of CPs (2,4,6-trichlorophenol) sorption from artificial wastewater confirm superiority of PS organogel to absorb 1746 μmol CPs/g (∼345 mg CPs/g) at broad pH (4–10) and temperature (25–45 °C). Based on ANOVA statistic, simulated CPs absorption model onto PS organogel was successfully developed, with accuracy of prediction of R2≈ RAdj2 of 0.991–0.995 and lower coefficient of variation of 2.73% with Fmodel of 611.4 at p < .0001. Particularly, the usage of PS organogel for petroleum wastewater reclamation exhibited higher absorption affinities for all the organic contaminants especially for CPs (>99%) by non-covalent and/or dispersive interaction mechanisms with a well-term reusability and good stability up to 5 cycles.