Iodide Salts Research Articles

Investigate the Thermal Analysis Properties of Polymer Electrolyte

Propylene carbonate (PC) (1:1) have been used as plasticizer to synthesized two series of polymer blend electrolytes (As and Cs) composed of Poly (methyl methacrylate) (PMMA)/Polyacrylonitrile (PAN), (80/20) Wt.% and ethylene carbonate (EC) using solution cast technique. Mixed iodide salts and varying weight ratio of potassium iodide (KI) and cesium iodide (CsI) was used to study the thermal properties of polymer blend electrolytes (GPEs). Differential Scanning Calorimeter (DSC) results show a decrease in the glass transition of electrolytes when increasing the weight percentage of salts, while the melting point increases due to the reduction in the polymer fluidity. Thermogravimetric analysis (TGA) indicates that the increase in the thermal stability can be attributed to the high thermal stability of polymer blend and the existence of the strong interaction between the two polymers. The optimum value of glass transition (Ts) is 104.2 °C found in sample containing 35 Wt.% of KI salt which has a melting point (Tm) 194.7 °C.

Effects of different iodide salts on the electrical and electrochemical properties of hybrid biopolymer electrolytes for dye-sensitized solar cells application

Effects of different iodide salts on the electrical and electrochemical properties of hybrid biopolymer electrolytes for dye-sensitized solar cells application

Review on the Revolution of Polymer Electrolytes for Dye-Sensitized Solar Cells

Dye-sensitized solar cells (DSSCs) are a suitable replacement for conventional silicon solar cells due to their unique features, such as high energy conversion efficiency and cheap manufacturing cost. The liquid-state DSSCs, however, are poorly sustainable on a long-term basis because volatile liquids are used. The early intention of incorporating polymer into the liquid electrolytes was to curb the problem encountered by liquid electrolytes and enable the DSSCs to function as a long-term stability device. This work briefly reviews how the improvisation has been done on the polymer electrolytes formulation and the extent of how each element can affect the cell efficiency and long-term stability. The role of each component, such as the type of host polymer, iodide salts, nanoparticles, and organic additives that improve the performance of DSSCs, has also been highlighted. This clarified the main purpose of introducing various types of additives into electrolytes to enhance the transport properties as well as the performance of the DSSCs.

Sonochemically synthesized cobalt oxide nanoparticles as an additive for natural polymer iodide electrolyte based dye-sensitized solar cells

Hydroxypropyl cellulose (HPC)-based gel polymer electrolytes with different alkali metal iodide salts (potassium iodide, KI; sodium iodide, NaI; and lithium iodide, LiI) were investigated. Electrochemical impedance spectroscopy (EIS) was used to examine the electrochemical properties of the electrolytes. The electrolyte containing KI salt (KI sample) has the highest ionic conductivity. The trend of conductivity of the samples developed as follows, KI > NaI > LiI. A hybrid gel polymer electrolyte (HGPE) was developed to further enhance the property by incorporating sonochemically synthesized cobalt oxide (Co3O4) nanoparticles into the KI sample. The nanoparticles were studied by field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). HGPEs containing various amounts of synthesized Co3O4 nanoparticles were examined with EIS, XRD, and Linear Sweep Voltammetry (LSV). The introduction of Co3O4 nanoparticles has improved the ionic conductivity, reduced activation energy and degree of crystallinity of the HGPEs. Dye-sensitized solar cells (DSSCs) assembled with the developed HGPEs have shown an improvement in short-circuit current density and efficiency. HGPE containing 7 wt% of Co3O4 nanoparticles achieved the best ionic conductivity and photovoltaic performance of DSSC of 8.02 mS cm−1 and 5.8%, respectively.

Cationic porphyrazines with morpholinoethyl substituents – Syntheses, optical properties, and photocytotoxicities

Novel cationic water-soluble magnesium(II) and zinc(II) sulfanyl porphyrazines with peripheral N-methylmorpholinoethyl iodide moieties in the form of iodide salts were synthesized and characterized with ESI MS, UV–Vis, and NMR. The subsequent logPo/w values were lower for octaiodide salts than those for their neutral precursors and, therefore the macrocycles were considered hydrophilic. After measuring the binding constants Kb, it becomes clear that the obtained cationic porphyrazines, as well as the neutral porphyrazines, were poor liposome binders. The cationic water-soluble magnesium(II) and zinc(II) sulfanyl porphyrazines revealed moderate singlet oxygen generation yields and higher susceptibility to decomposition after light exposition. In the antimicrobial studies, magnesium(II) porphyrazine with peripheral N-methylmorpholinoethyl groups presented a log reduction up to 6.5 against Gram-positive bacteria. In vitro, photocytotoxic activity assessments of magnesium(II) and zinc(II) porphyrazines with peripheral N-methylmorpholinoethyl, as well as magnesium(II) sulfanyl porphyrazine derivative in the form of iodide salt, were performed on two types of oral cancer cells – SCC-25 and CAL-27. Zinc(II) sulfanyl porphyrazine with peripheral N-methylmorpholinoethyl groups decreased the viability of the SCC-25 cell line after light irradiation with IC50 at 6.46 μM in its free form and at 3.61 μM after encapsulation in liposomal formulation. The opposite phenomenon was observed for magnesium(II) sulfanyl porphyrazine with peripheral N-methylmorpholinoethyl groups. The magnesium(II) sulfanyl porphyrazine derivative in the form of iodide salt did not demonstrate any photocytotoxicity in the studied cell lines.

Salts of 4-[(benzyl-amino)-carbon-yl]-1-methyl-pyridinium and iodide anions with different cation:iodine stoichiometric ratios.

The two iodide salts, 4-[(benzyl-amino)-carbon-yl]-1-methyl-pyridinium iodide-iodine (2/1), C14H15N2O+·I-·0.5I2, I, and 4-[(benzyl-amino)-carbon-yl]-1-methyl-pyridinium triiodide, C14H15N2O+·I3 -, II, with different cation:iodine atoms ratios were studied. Salt I contains one cation, one iodide anion and half of the neutral I2 mol-ecule in the asymmetric unit (cation:iodine atoms ratio is 1:2). Salt II contains two cations, one triiodide anion (I 3 -) and two half triiodide anions (cation:iodine atoms ratio is 1:3). The NH group forms N-H⋯I hydrogen bonds with the I- anion in the crystal of I or N-H⋯O hydrogen bonds in II where only triiodide anions are present.

L-Prolinium l-proline halogenides: a comparison of the respective chloride, bromide and iodide salts

• # Chloride, bromide and iodide salts with l -prolinium l -proline dimeric cation were studied • # Tetragonal chloride and bromide are isostructural, while iodide is orthorhombic • # Short O-H…O hydrogen bonds of dimeric cations are reflected in the infrared spectra • # Isostructural chloride and bromide are not SHG-active in agreement with Kleinman condition Structures and vibrational spectra of l -prolinium l -proline chloride (I), l -prolinium l -proline bromide (II) and l -prolinium l -proline iodide (III) were analyzed at 100K, 200K and room temperature (RT). The salts (I) and (II) are isostructural and crystallize in the tetragonal space group P 4 1 2 1 2, Z=8 at RT and in orthorhombic P 2 1 2 1 2 1 , Z=8 at 100K and 200K. The salt (III) is orthorhombic, space group P 2 1 2 1 2 1 , Z=4 at all three temperatures. The O⋅⋅⋅O distances in l -prolinium l -proline dimeric cations are equal to 2.464(3) Å (I), 2.456(3) Å (II) and 2.456(4) Å (III) at RT. The presence of strong hydrogen bonds in the crystal structures is reflected in the infrared spectra. The influence of symmetry on second harmonic activity is discussed.

Structural and electrical properties of polyvinyl alcohol (PVA):Methyl cellulose (MC) based solid polymer blend electrolytes inserted with sodium iodide (NaI) salt

This paper studies the structural and electrical properties of solid polymer blend electrolytes based on polyvinyl alcohol (PVA) and methylcellulose (MC) incorporated with sodium iodide (NaI). The polymer electrolyte films were assembled through a solution casting technique. The host matrix, which is doped with different NaI salt concentrations between 10 and 50 wt%, utilizes the most amorphous blend compositions (60 wt% Polyvinyl alcohol and 40 wt% methylcellulose). The structural behaviour of the electrolyte films was examined utilizing X-ray diffraction (XRD) and Fourier transformation infrared (FTIR) techniques. The semi crystalline nature of PVA:MC with inserted NaI was derived from the X-ray diffraction studies, while the XRD analysis suggests that the highest ion conductive sample displays the minimum crystalline nature. The interaction between polymer blends and inserted salt was conceived from the FTIR investigation. Shifting of peaks and variation in the intensity of FTIR bands was detected. To investigate the structural properties and calculate the degree of crystallinity of the films, the (XRD) technique was employed, while electrical impedance spectroscopy (EIS) was utilized for studying the conductivity of the samples. In order to comprehend all of the electrical properties of the ion-conducting systems, the EIS outcome of each electrolyte was matched with Equivalent Electrical Circuits ( EEC) s. Ion transport parameters including mobility, carrier density and diffusion are well assessed for the samples and the dielectric properties were compared with the conductivity measurement. At lower frequencies, the dielectric constant was elevated and dielectric loss was detected. Loss tangent and electric modulus plots were used to study the relaxation nature of the samples. The highest ambient temperature conductivity of PVA loaded 50 wt% of NaI was determined to be 1.53 × 10 −5 S/cm. The loss tangent relaxation peak shifts towards high-frequency side which indicates the decrease of relaxation time and faster ion dynamics.

Visible-Light-Induced Selective Photolysis of Phosphonium Iodide Salts for Monofluoromethylations.

The sigma (σ)-hole effect has emerged as a promising tool to construct novel architectures endowed with new properties. A simple yet effective strategy for the generation of monofluoromethyl radicals is a continuing challenge within the synthetic community. Fluoromethylphosphonium salts are easily available, air- and thermally stable, as well as simple-to-handle. Herein, we report the ability of the σ-hole effect to facilitate the visible-light-triggered photolysis of phosphonium iodide salts, a charge-transfer complex, selectively giving fluoromethyl radicals. The usefulness and versatility of this new protocol are demonstrated through the mono-, di-, and trifluoromethylation of a variety of alkenes.

Visible‐Light‐Induced Selective Photolysis of Phosphonium Iodide Salts for Monofluoromethylations

AbstractThe sigma (σ)‐hole effect has emerged as a promising tool to construct novel architectures endowed with new properties. A simple yet effective strategy for the generation of monofluoromethyl radicals is a continuing challenge within the synthetic community. Fluoromethylphosphonium salts are easily available, air‐ and thermally stable, as well as simple‐to‐handle. Herein, we report the ability of the σ‐hole effect to facilitate the visible‐light‐triggered photolysis of phosphonium iodide salts, a charge‐transfer complex, selectively giving fluoromethyl radicals. The usefulness and versatility of this new protocol are demonstrated through the mono‐, di‐, and trifluoromethylation of a variety of alkenes.

Mechanism of a new photosensitizer (TBZPy) in the treatment of high-risk human papillomavirus-related diseases

BackgroundHigh-risk human papillomavirus infection is closely related to the development of several diseases, including cervical cancer and condyloma acuminatum. We recently designed a new photosensitizer, 1-triphenylaminebenzo[c][1,2,5]thiadiazole-4-yl)styryl)-1-methylpyridin-1-ium iodide salt (TBZPy), which shows good photodynamic properties. In this study, we explored the mechanism of action of the TBZPy photosensitizer and its potential application in the treatment of high-risk human papillomavirus-related diseases. MethodsHeLa cells (infected by the high-risk human papillomavirus strain HPV18) were treated with TBZPy-photodynamic therapy (PDT). Cell viability, production of reactive oxygen species, apoptosis, and mitochondrial membrane depolarization were evaluated using cell counting kit-8, immunofluorescence, and flow cytometry assays, respectively. Expression levels of the anti-apoptotic proteins Bcl-2 and Bcl-XL; pro-apoptotic proteins Bax, cytochrome C, cleaved caspase 3, and cleaved caspase 9; and the mitochondrial stress protein heat shock protein 60 were examined by western blotting. ResultsTBZPy-PDT inhibited the viability and promoted reactive oxygen species production, lactate dehydrogenase release, and apoptosis of HeLa cells in vitro. TBZPy-PDT also promoted the loss of mitochondrial membrane potential, downregulated the expression of anti-apoptotic proteins, and upregulated the expression of pro-apoptotic proteins. Moreover, TBZPy-PDT downregulated the expression of the human papillomavirus E6 and E7 proteins. ConclusionOur study demonstrates the effectiveness of TBZPy-PDT against human papillomavirus-related diseases. These findings provide a foundation for using this novel photosensitizer to treat diseases associated with high-risk human papillomavirus infection.

Crystal Structures and Optical Properties of Cyanine Dyes Depending on Various Counter Anions.

In this study, cyanine cations with various counter anions were prepared as examples of ionic materials constructed using charged π-conjugated systems. A series of ion pairs was obtained by anion exchange reactions using iodide salts of carbocyanine dyes. The optical properties were measured by UV/vis absorption and fluorescence spectroscopy; measurements performed in CHCl3 (less-polar solvent) were altered by the influence of the counter anions. The packing structures of nine crystals were determined by single-crystal X-ray analysis. Moreover, the locations of the anions relative to the cations were stabilized by hydrogen bonding and categorized into two types. In addition, delocalization of the negative charge of the anions on cyanine cations was explained by density functional theory calculations. Furthermore, it was concluded that the stack formation of cyanine cations depends on the size and structure of the anions.

Bismuth(III) Iodide Complexes with 1-Ethyl-4-Dimethylaminopyridinium: Structure, Thermal Stability, and Optical Properties

Polynuclear bismuth(III) iodide complexes with 1-ethyl-4-dimethylaminopyridinium (1-EtDMAP)4[Bi8I28] (1) and (1-EtDMAP)BiI4 (2) have been obtained by the reactions of bismuth(III) iodide with an organic iodide salt cations in organic solvents and characterized by X-ray diffraction. The optical properties and thermal stability of the obtained compounds have been studied.

A Pivotal Role of Chloride Ion on Nickel-Catalyzed Enantioselective Reductive Cross-Coupling to Perfluoroalkylated Boronate Esters

The enantioselective construction of perfluoroalkyl-containing molecules is essential in materials science, agrochemistry, and medicinal chemistry. Herein, a nickel-catalyzed reductive cross-coupling was reported to generate chiral perfluoroalkylated boronate esters from the easily prepared perfluoroalkyl-substituted α-iodoboronates. The simple and mild conditions enable a broad range of aryl iodides to deliver the products in good enantioselectivities. Additionally, compared with common acceleration by iodide salts on substrate activation, the effect of the additive was systematically investigated to disclose a pivotal role of chloride ion on nickel reduction for this transformation.

Exploring the Effect of Ammonium Iodide Salts Employed in Multication Perovskite Solar Cells with a Carbon Electrode.

Perovskite solar cells that use carbon (C) as a replacement of the typical metal electrodes, which are most commonly employed, have received growing interest over the past years, owing to their low cost, ease of fabrication and high stability under ambient conditions. Even though Power Conversion Efficiencies (PCEs) have increased over the years, there is still room for improvement, in order to compete with metal-based devices, which exceed 25% efficiency. With the scope of increasing the PCE of Carbon based Perovskite Solar Cells (C-PSCs), in this work we have employed a series of ammonium iodides (ammonium iodide, ethylammonium iodide, tetrabutyl ammonium iodide, phenethylammonium iodide and 5-ammonium valeric acid iodide) as additives in the multiple cation-mixed halide perovskite precursor solution. This has led to a significant increase in the PCE of the corresponding devices, by having a positive impact on the photocurrent values obtained, which exhibited an increase exceeding 20%, from 19.8 mA/cm2, for the reference perovskite, to 24 mA/cm2, for the additive-based perovskite. At the same time, the ammonium iodide salts were used in a post-treatment method. By passivating the defects, which provide charge recombination centers, an improved performance of the C-PSCs has been achieved, with enhanced FF values reaching 59%, which is a promising result for C-PSCs, and Voc values up to 850 mV. By combining the results of these parallel investigations, C-PSCs of the triple mesoscopic structure with a PCE exceeding 10% have been achieved, while the in-depth investigation of the effects of ammonium iodides in this PSC structure provide a fruitful insight towards the optimum exploitation of interface and bulk engineering, for high efficiency and stable C-PSCs, with a structure that is favorable for large area applications.

Iodine‐Catalyzed or ‐Mediated Reactions in Aqueous Medium

AbstractTransition metal‐catalyzed reactions are the heart of modern organic synthetic chemistry. In most cases, the synthesis of target molecules involved at least one or more transition metals such as palladium, ruthenium, rhodium, platinum, iridium, rhenium, cobalt, copper, iron, etc. But these transition metals are costly, toxic, and sometimes very difficult to separate from the target product. Instead of transition metals, molecular iodine or iodide salts have drawn the attention of modern organic synthetic chemists over a few decades due to their inexpensiveness, tolerance, and environmentally benign nature. So molecular iodine or iodide catalyzed reactions are highly efficient, atom‐economical, easy to control, eco‐ friendly protocol rather than transition metal‐catalyzed reactions. But many iodine‐catalyzed or mediated reactions, toxic solvents like tetrahydrofuran (THF), 1,4 dioxane, dimethylacetamide (DMA), dimethylformamide (DMF), benzene, toluene, chlorobenzene, nitrobenzene, n‐hexane, etc. are used which is a major concern in terms of environmental issues. Therefore, our present endeavour focuses on the recent developments (mainly in the period 2005–2020) of the iodine‐catalyzed or iodine‐mediated various reactions like oxidative additions, condensation reactions, C−C, C−N, C−O, C−S cross‐couplings etc. consciously performed in an aqueous medium to avoid environmental hazardous, which is a thrust area to the young researchers.

Mixed-Halide Double Perovskite Cs2 AgBiX6 (X=Br, I) with Tunable Optical Properties via Anion Exchange.

Lead‐free double perovskites, A2M+M′3+X6, are considered as promising alternatives to lead‐halide perovskites, in optoelectronics applications. Although iodide (I) and bromide (Br) mixing is a versatile tool for bandgap tuning in lead perovskites, similar mixed I/Br double perovskite films have not been reported in double perovskites, which may be due to the large activation energy for ion migration. In this work, mixed Br/I double perovskites were realized utilizing an anion exchange method starting from Cs2AgBiBr6 solid thin‐films with large grain‐size. The optical and structural properties were studied experimentally and theoretically. Importantly, the halide exchange mechanism was investigated. Hydroiodic acid was the key factor to facilitate the halide exchange reaction, through a dissolution–recrystallization process. In addition, the common organic iodide salts could successfully perform halide‐exchange while retaining high mixed‐halide phase stability and strong light absorption capability.

A Study of Methylcellulose Based Polymer Electrolyte Impregnated with Potassium Ion Conducting Carrier: Impedance, EEC Modeling, FTIR, Dielectric, and Device Characteristics.

In this research, a biopolymer-based electrolyte system involving methylcellulose (MC) as a host polymeric material and potassium iodide (KI) salt as the ionic source was prepared by solution cast technique. The electrolyte with the highest conductivity was used for device application of electrochemical double-layer capacitor (EDLC) with high specific capacitance. The electrical, structural, and electrochemical characteristics of the electrolyte systems were investigated using various techniques. According to electrochemical impedance spectroscopy (EIS), the bulk resistance (Rb) decreased from 3.3 × 105 to 8 × 102 Ω with the increase of salt concentration from 10 wt % to 40 wt % and the ionic conductivity was found to be 1.93 ×10−5 S/cm. The dielectric analysis further verified the conductivity trends. Low-frequency regions showed high dielectric constant, ε′ and loss, ε″ values. The polymer-salt complexation between (MC) and (KI) was shown through a Fourier transformed infrared spectroscopy (FTIR) studies. The analysis of transference number measurement (TNM) supported ions were predominantly responsible for the transport process in the MC-KI electrolyte. The highest conducting sample was observed to be electrochemically constant as the potential was swept linearly up to 1.8 V using linear sweep voltammetry (LSV). The cyclic voltammetry (CV) profile reveals the absence of a redox peak, indicating the presence of a charge double-layer between the surface of activated carbon electrodes and electrolytes. The maximum specific capacitance, Cs value was obtained as 118.4 F/g at the sweep rate of 10 mV/s.

Stepwise Iodide-Free Methanol Carbonylation via Methyl Acetate Activation by Pincer Iridium Complexes.

Iodide is an essential promoter in the industrial production of acetic acid via methanol carbonylation, but it also contributes to reactor corrosion and catalyst deactivation. Here we report that iridium pincer complexes mediate the individual steps of methanol carbonylation to methyl acetate in the absence of methyl iodide or iodide salts. Iodide-free methylation is achieved under mild conditions by an aminophenylphosphinite pincer iridium(I) dinitrogen complex through net C-O oxidative addition of methyl acetate to produce an isolable methyliridium(III) acetate complex. Experimental and computational studies provide evidence for methylation via initial C-H bond activation followed by acetate migration, facilitated by amine hemilability. Subsequent CO insertion and reductive elimination in methanol solution produced methyl acetate and acetic acid. The net reaction is methanol carbonylation to acetic acid using methyl acetate as a promoter alongside conversion of an iridium dinitrogen complex to an iridium carbonyl complex. Kinetic studies of migratory insertion and reductive elimination reveal essential roles of the solvent methanol and distinct features of acetate and iodide anions that are relevant to the design of future catalysts for iodide-free carbonylation.

Influence of Shape-Directing Agents on the Formation of Anisotropic Gold Nanoparticles

Understanding the role of shape-directing substances is crucial for the controllable preparation of anisotropic nanostructures through solution growths. Herein, we report a comparative investigation about the morphologies and structures of Au nanoparticles (Au NPs) synthesized using two different capping agents (hexadecyltrimethylammonium chloride (CTAC) and polyvinylpyrrolidone (PVP)) with/without the addition of iodide salts. The study manifests a synergistic effect of shape-directing agents on the growth pathways and shape formation. Depending on the specific use of surfactants/polymers, the iodide additives can promote the growth of prismatic anisotropic nanoparticles or lead to the shape evolution from irregular to quasi-spherical configurations.