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As a biodegradable polyester, the commercialized synthesis protocol of poly(ε-caprolactone) (PCL) under mild conditions is of great significance and attractive. Herein, the ring-opening polymerization (ROP) of ε-caprolactone (ε-CL) using FeCl3 catalyst and benzyl alcohol (BnOH) as the initiator was developed. FeCl3 has been proved to be an efficient catalyst for the ROP of ε-CL under mild conditions. The conversion of ε-CL to PCL was 98.8% at 60 °C within 4 h, with number-average molecular weight (Mn) and dispersity (PDI) of 1.65 × 104 g/mol and 1.28, respectively. Moreover, a coordination-insertion ring-opening polymerization mechanism mediated by FeCl3 was proposed. Overall, this work is expected to provide a feasible industrial method for the preparation of PCL from the direct aerobic oxidation of cyclohexanone. [ABSTRACT FROM AUTHOR]

A comparative analysis of the composition and structure of freshly precipitated iron(III) hydroxide precipitates obtained from a sodium sulfate solution (400 mg/L) at pH 7 and 8 before and after the sorption of nickel ions on them was carried out. IR, Raman, and Mössbauer spectroscopy, as well as X-ray diffraction and thermal analyses, have shown that precipitates synthesized from a solution of iron(III) chloride are a two-line ferrihydrite with the gross formula Fe2O3⋅3H2O. It has been established that the sorption of nickel ions on these precipitates is not accompanied with chemisorption, i.e., the formation of mixed compounds between iron and nickel. Their doping with nickel ions also was not observed. It has been found that the ζ potential of ferrihydrite particles at pH < 5.4 has a positive value, whereas it becomes negative at pH > 5.4. The zero-charge point of the precipitate particles corresponds to pH 5.4. [ABSTRACT FROM AUTHOR]

The complex salts (R-BpH)[MAnx], where R-BpH is the protonated 3-arylidene-1-pyrrolinium cation, An is the chloride, nitrate, or dimethylmalonate anion, were synthesized by reactions of 3-arylidene-1-pyrrolinium trifluoroacetates with zinc(II) chloride, copper(II) nitrate, and iron(III) chloride or iron(III) dimethylmalonate. All products were characterized by IR spectroscopy and X-ray diffraction (CCDC nos. 2169556–2169560). It was shown that all crystal structures are formed by classical N–H...O and O–H...O type hydrogen bonds between the complex anions and the protonated organic molecules and by π...π contacts between the latter. [ABSTRACT FROM AUTHOR]

The present work demonstrates that the use of iron(III) hydroxide as a sorbent fabricated by precipitation from a solution of iron(III) chloride can purify contaminated solutions from toxic nickel ions. The study was performed at room temperature on a model of solution of sodium sulfate (400 mg/L) simulating polluted natural and wastewater. It has been shown that the removal of nickel ions from the model solution by iron(III) hydroxide precipitate at pH 7 and 8 is described with a satisfactory accuracy by the classical adsorption isotherms of Freundlich, Langmuir, and Dubinin–Radushkevich. Low values of the free energy of adsorption that do not exceed 8 kJ/mol indicate the physical nature of adsorption and exclude ion-exchange interaction of nickel ions with iron(III) hydroxide. The most complete removal of nickel ions from the solution occurs during the sorption with iron(III) hydroxide at pH 8. The sorption capacity of iron(III) hydroxide toward nickel ions at both pH 7 and 8 is almost an order of magnitude higher than the same value for many mineral, carbon, and coal sorbents. During the sorption process at pH 7, the adsorption capacity of iron(III) hydroxide precipitates decreases along with the increase of the initial concentration of iron(III) ions in solution, whereas during sorption at pH 8, on the contrary, it remains constant and does not depend on the initial concentration of iron(III) ions in the solution. The obtained data enable one to select the concentration of iron(III) hydroxide precipitate required to achieve a preset depth of purification of contaminated solutions from nickel ions. [ABSTRACT FROM AUTHOR]

The carbonization of carbohydrates (glucose, sucrose, and starch) in an inert gas atmosphere of argon and under the action of calcium chloride and iron(III) chloride additives was studied. It was established that the addition of calcium and iron(III) chlorides exerted a peculiar catalytic effect on the carbonization process. Carbon production can be carried out at lower temperatures to 200°С. In traditional methods of synthesis, carbonization upon the decomposition of carbohydrates occurs at temperatures of 300–800°C. It was found that the process of carbon production was accompanied by the release of heat, which was confirmed by thermodynamic calculations of the chemical reaction of carbon production and experimental studies of the carbonization of carbohydrates by differential scanning calorimetry. A regular decrease in the yield of carbon, as compared to a maximum theoretically possible one, was observed in the order glucose > sucrose > starch. It was established that the heat of combustion of carbon obtained upon the carbonization of carbohydrates under the action calcium and iron chlorides reached 34 MJ/kg or more due to the presence of structural fragments that do not occupy energetically favorable positions compared to the graphite structure. The presence of the structural fragments of carbon was established by X-ray phase analysis of powder diffraction patterns. [ABSTRACT FROM AUTHOR]

Many biologically active nicotinonitriles have been reported to date. Consequently, the development of synthetic methods for multiply arylated/alkylated nicotinonitriles remains a sought-after field of research. In the present work, a new synthetic strategy for multi-substituted nicotinonitriles is described. A FeCl3-promoted condensation–cyclization reaction of an enamino nitrile and α,β-unsaturated ketones proceeded efficiently with a wide range of substrates. It is noteworthy that this method facilitates access to fully and differently substituted nicotinonitriles, including tetra-arylated nicotinonitriles, in only three steps. Using the functionality of the cyano group, the copper-catalyzed annulation reaction of the nicotinonitrile was achieved to yield benzo-[ c ][2,7]naphthyridin-5(6 H)-one. [ABSTRACT FROM AUTHOR]

During our research work, we examined the removal of contaminants from synthetically produced bathing waters using different coagulants and studied the efficiency and the mechanism of coagulation-flocculation processes in detail. In our work, we performed experiments with two different types of coagulants (iron(III) chloride and polyelectrolyte) and compared their efficiencies. The zeta potential and its change were monitored as a qualifying parameter while other water quality parameters were also analyzed. In our experiments, a newly acquired flocculator device was also used to study the coagulation-flocculation processes of larger volume samples. The main goal of our research is to promote the sustainable management of drinking water quality and to study the bathing water reuse possibilities. [ABSTRACT FROM AUTHOR]

The extraction equilibria in undecan-1-ol–HCl (2.5–9.45 M) systems in the absence and in the presence of 0.55 M FeCl3 were studied. The distribution coefficients of HCl, as well as of HCl and Fe(III) for simultaneous extraction into undecane-1-ol were measured. Two mathematical models including the material balance equations on the basis of the extraction of HCl and FeIII ions by the hydration– solvation mechanism were proposed. The compositions of extracted complexes were studied. [ABSTRACT FROM AUTHOR]

The potato‐processing wastewater (PPW) treatment method employe a combined process of chemical coagulation/flocculation and membrane filtration. Four different inorganic coagulants are used: polyaluminium chloride, alum, iron(III) chloride and iron(II) sulphate. The results show that the inorganic coagulants enhanced both chemical oxygen demand (COD) with turbidity removal at 1 g/L of concentration. Iron(III) chloride is the most efficient for COD and turbidity removal efficiencies of 54% and 88%, respectively. At pH=6, COD and turbidity elimination performances are enhanced to 67% and 96%, respectively. The findings suggest that coagulation plays a key role in the removal of COD and turbidity of PPW, but water quality is again improved by a second stage of treatment. The utilisation of ultrafiltration (UP150) at 1 bar of transmembrane pressure (TMP) has highly improved water quality. At the end of this research, a comparative study is conducted between the combined process: coagulation/flocculation‐membrane filtration and direct filtration of raw PPW. The results demonstrate that the primary stage of treatment is necessary to prevent early membrane fouling and provided high permeate flux. Even though, the most used treatments rely on combined coagulation/flocculation and membrane filtration systems, very few research articles are reported for PPW treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • An effective DES and FeCl 3 combination pretreatment system was developed. • FeCl 3 /ChCl:NE could remove lignin (87.0%) and xylan (55.9%) in corn straw (CS). • A high enzymatic saccharification (98.6%) was obtained from pretreated CS. • FeCl 3 /ChCl:NE improved enzymatic saccharification by 5.5 times compared to raw CS. An effective deep eutectic solvent (DES) and Iron(III) chloride (FeCl 3) combination pretreatment system was developed to improve the removal efficiency of lignin and hemicellulose from corn stover (CS) and enhance its saccharification. N -(2-hydroxyethyl)ethylenediamine (NE) was selected as the hydrogen-bond-donor for preparing ChCl-based DES (ChCl:NE), and a mixture of ChCl:NE (60 wt%) and FeCl 3 (0.5 wt%) was utilized for combination pretreatment of CS at 110 ℃ for 50 min. FeCl 3 /ChCl:NE effectively removed lignin (87.0 %) and xylan (55.9 %) and the enzymatic hydrolysis activity of FeCl 3 /ChCl:NE-treated CS was 5.5 times that of CS. The reducing sugar yield of pretreated CS was 98.6 %. FeCl 3 /ChCl:NE significantly disrupted the crystal structure of cellulose in CS and improved the removal of lignin and hemicellulose, enhancing the conversion of cellulose and hemicellulose into monomeric sugars. Overall, this combination of FeCl 3 and DES pretreatment methods has high application potential for the biological refining of lignocellulose. [ABSTRACT FROM AUTHOR]

Abstract A facile synthesis of 2,3-disubstituted carbazoles through electrocyclization of 2,3-divinylindoles using FeCl3 in DMF at reflux is reported. The methodology was found to be applicable for smooth transformation of 3-aryl-2-vinylindole as well as 2-styrylbiphenyl into the respective benzo[c]carbazole and phenanthrene.

A highly efficient method has been developed for the synthesis of diphenylmethyl (DPM) esters from 2-diphenylmethoxypyridine. Various carboxylic acids readily reacted with 2-diphenylmethoxypyridine in the presence of FeCl3 as a catalyst to provide the desired DPM esters with high yields. The procedure is facile and enables effective synthesis of a variety of esters for the protection of carboxylic acids. [ABSTRACT FROM AUTHOR]

The results of experimental investigation of the interphase distribution of iron(III) in an environmentally friendly aqueous two-phase system based on polypropylene glycol with a molecular weight of 425 and sodium chloride have been presented. The mechanism of extraction has been determined, and the quantitative characteristics of the extraction of iron(III) using the system under study have been found. [ABSTRACT FROM AUTHOR]

The FeCl3-mediated condensation of an α-phenylenamino ester and an enone proceeds efficiently to afford a 2-phenylnicotinate. The subsequent intramolecular Friedel–Crafts reaction yielded an -onychine framework. Modifications at the 2-, 3-, and 8-positions of the onychine framework were easily achieved by altering the enamino esters- and enones, which facilitated the discovery of potentially bioactive compounds. [ABSTRACT FROM AUTHOR]

The antagonistic effects of water hardness have led to a decrease in herbicides' efficacy, especially in regions where the bedrock is mainly composed of lime and dolomite. In such conditions, tank mixtures of herbicides may improve herbicides' efficacy. Our study evaluated how different agents of water hardness, such as calcium chloride (CaCl 2), magnesium chloride (MgCl 2), iron(III) chloride (FeCl 3), and deionized water (without water hardness), affect the tank mixture of 2,4-D amine and sulfosulfuron in various ratios (0:100, 25:75, 50:50, 75:25, and 100:0). The results showed that the efficacy of both herbicides in decreasing the biomass and survival of flixweed [ Descurainia sophia (L.) Webb ex Prantl] decreased when exposed to water hardness agents. In the case of 2,4-D amine and sulfosulfuron, the presence of water hardness caused by iron(III) chloride resulted in a 45% and 52% increase in the ED 50 of biomass, respectively, compared to the condition without water hardness. The lowest ED 50 values for survival were obtained with deionized water (10.06 g a.i. ha−1), CaCl 2 (39.21 g a.i. ha−1), MgCl 2 (12.08 g a.i. ha−1), and FeCl 3 (36.60 g a.i. ha−1) in different ratios of 2,4-D amine and sulfosulfuron (50:50, 25:75, 50:50, and 25:75). Isobolographic analysis was used to confirm the mixture effects of these herbicides, which corroborated the dose-response findings of this study. Based on the concentration addition and Hewlett models, herbicides' efficacy was higher when used in tank mixing, especially in a 50:50 ratio, compared to using them alone. This study proved that tank mixing these herbicides prevents them from reducing their efficacy in controlling broadleaf weeds such as flixweed in areas with water hardness. In addition, using these herbicides in a tank mixture may be beneficial in delaying the development of herbicide resistance and the shift in weed flora that often occurs when a single herbicide is used. • Water hardness decreased the efficacy of both herbicides in decreasing the biomass and survival of flixweed. • Iron(III) chloride caused the most significant decrease in efficacy. • Tank mixing 75% sulfosulfuron and 25% 2,4-D amine with iron(III) chloride is the most effective in reducing survival by 50%. • The synergistic or antagonistic effects of herbicide mixtures can vary depending on the specific conditions and herbicides used. • The isobole diagrams show the different ratios of the two herbicides and their effects on flixweed biomass. [ABSTRACT FROM AUTHOR]

Amide functional groups are prominent in a broad range of organic compounds with diverse beneficial applications. In this work, we report the synthesis of these functional groups via an iron(iii) chloride-catalyzed direct amidation of esters. The reactions are conducted under solvent-free conditions and found to be compatible with a range of amine and ester substrates generating the desired amides in short reaction times and good to excellent yields at a catalyst loading of 15 mol%.

One of the problems of BrO 3 − detection using the electrochemical method, such as a cyclic voltammetry (CV) is that it is impressionable to interferences from Humic acid (HA). The objective of this study was to determine the effect of HA on electrochemical detection of BrO 3 − using metalloporphyrin-based multilayer sensor under different pH conditions in the presence of FeCl 3 . The effect of HA interference on chemical interaction at the electrode surface in the presence of FeCl 3 was determined based on Fourier transform infrared spectrum. CV was used to measure the concentration of BrO 3 − in the solution containing HA with or without different concentrations of FeCl 3 . Results of CV revealed a dynamic linear concentration range of BrO 3 − from 10 to 100 μg/L in 0.1 to 1 mg/L of HA solution (pH 9). The detection limit for BrO 3 − concentration was 8.9 μg/L in 0.1 mg/L of HA solution. [ABSTRACT FROM AUTHOR]

An efficient and mild method for the synthesis of α-halomethyl ketones from α-diazo ketones was developed using ferric chloride or bromide as the halogen source and silica gel as the hydrogen source, with good to excellent yields. [ABSTRACT FROM AUTHOR]

A one-pot preparation of pyridyl isothiocyanates (ITCs) from their corresponding amines has been developed. This method involves aqueous iron(III) chloride-mediated desulfurization of a dithiocarbamate salt that is generated in situ by treatment of an amine with carbon disulfide in the present of DABCO or sodium hydride. The choice of base is of decisive importance for the formation of the dithiocarbamate salts. This one-pot process works well for a wide range of pyridyl ITCs. Utilizing this protocol, some highly electron-deficient pyridyl and aryl ITCs are obtained in moderate to good yields.

New hybrid compounds, thienopyrimidinyl-1 H-pyrazolo[3,4- b]pyridine derivatives, were efficiently synthesized by the three-component reaction of 3-phenyl-1-(thienopyrimidin-4-yl)-1 H-pyrazol-5-amine, benzoylacetonitrile and an aromatic aldehyde in the presence of FeCl3 on basic alumina. [ABSTRACT FROM AUTHOR]

A mild, catalytic method for the synthesis of 3-carboxy-2,5-disubstituted furans is reported proceeding via a 5-exo-dig cycloisomerization reaction. The iron(III) chloride-catalyzed transformation of aryl- and alkyl β-ketoesters enables synthetic access to functionalized furan core structures found in many natural products and complex molecules of biological importance. The method described herein, represents a mild and efficient alternative to currently available reaction protocols. [ABSTRACT FROM AUTHOR]

Kraft lignin was catalytically graphitized to graphene-based nanostructures at 1000 °C under argon atmosphere with four iron catalysts, iron(III) nitrate (Fe-N); iron(II) chloride (Fe-Cl2); iron(III) chloride (Fe-Cl3); and iron(II) sulfate (Fe-S). The catalytic decomposition process of iron-promoted lignin materials was examined using thermalgravimetric analysis and temperature-programmed decomposition methods. The crystal structure, morphology and surface area of produced materials were characterized by means of X-ray diffraction, Raman, scanning electron microscopy, high resolution transmission electron microscopy and N2 adsorption−desorption techniques. Experimental results indicated that iron nitrate catalyst had better iron dispersion three other iron salts. Iron nitrate was the most active catalyst among four iron salts. The low activity of iron in iron chloride-promoted samples was because the residual chlorine over iron surfaces prevent iron interaction with lignin functional groups.

A general, facile, and efficient method is presented for the synthesis of 3-substituted 1,2,4-oxadiazoles from amidoximes and triethyl orthoformate. The procedure employs an iron(III) chloride/L-proline catalytic system and the 3-substituted 1,2,4-oxadiazole products are obtained in moderate to good yields. [ABSTRACT FROM AUTHOR]

An efficient and inexpensive spectrophotometric method has been developed for the determination of lactic acid in the individual state and in food and biological and cultural liquids. The method is based on the spectrophotometric determination of the colored product of the reaction of lactate ions with iron(III) chloride at 390 nm. The optimum conditions of the reaction have been found, and a calibration curve in the range from 0.3 to 10 g/L of lactic acid with the correlation coefficient 0.9999 has been constructed. The method does not require complex sample preparation. [ABSTRACT FROM AUTHOR]

An efficient approach for the synthesis of 1,2,3,4,5,6-hexahydrobenzo[ f]isoquinolines via a tandem aza-Prins/Friedel-Crafts cyclization from 2-arylethyl-2,3-butadienyl tosylamides and aldehydes has been developed. This iron(III) chloride-catalyzed cascade cyclization at the room temperature with different types of aldehydes, such as aromatic and heteroaromatic aldehydes, alkyl aldehydes, and α,β-unsaturated aldehydes, affords the products in moderate to excellent yields (up to 97 %). In this reaction, chlorotrimethylsilane was applied to activate the aldehydes. The cheap catalyst, the mild reaction conditions, and the broad scope of the substrates make this method highly useful. [ABSTRACT FROM AUTHOR]

Valuable compounds, naphthylarylketones are synthesized via oxy-Wittig (oxygenation of phosphonate carbanions) type reactions of diverse 1-naphthyl(aryl)methylphosphonates at room temperature by producing water soluble by-product. Commercially known but synthetically unexposed and expensive naphthylarylketones are easily synthesized using this transition metal-free, operationally simple strategy. As precursors, a range of new naphthyl(aryl)methylphosphonates are obtained in excellent yield and regioselectivity by direct and clean synthetic protocol that involves FeCl 3 or triflic acid (TfOH) mediated arylation reactions of easily accessible (hydroxy)-1-naphthylmethylphosphonate with activated as well as unactivated arenes including halogenated anisoles, biphenyl, naphthalene and pyrene (extended π-systems) at room temperature. [ABSTRACT FROM AUTHOR]

An efficient three-component synthesis of o-hydroxyphenyl-substituted pyrazolo[3,4-b]pyridines from substituted salicylic aldehydes, β-keto esters and 5-aminopyrazoles in the presence of FeCl3 is presented. Newly synthesized compounds were fully characterized by means of 1H NMR, 13C NMR, IR, HRMS and elemental analysis. [ABSTRACT FROM AUTHOR]

An efficient three-component synthesis of o-hydroxyphenyl-substituted pyrazolo[3,4-b]pyridines from substituted salicylic aldehydes, β-keto esters and 5-aminopyrazoles in the presence of FeCl3 is presented. Newly synthesized compounds were fully characterized by means of 1H NMR, 13C NMR, IR, HRMS and elemental analysis. [ABSTRACT FROM AUTHOR]

Iron-promoted cyclization of 1-benzyl-2-alkynylbenzenes with diorganyl diselenides led to the synthesis of 9-(organoselanyl)-5 H-benzo[7]annulenes whereby the mutual action between diorganyl diselenides and iron(III) chloride in a 0.5:1.0 mol ratio was essential in order to achieve the maximal yields of the products. The cyclization reaction tolerated a variety of functional groups, such as trifluoromethyl, chloro, fluoro and methoxy, in both the 1-benzyl-2-alkynylbenzenes and the diorganyl diselenides, giving the seven-membered heterocyclic products exclusively via a 7- endo- dig cyclization process. [ABSTRACT FROM AUTHOR]

A simple and efficient catalytic system including 3-methyl-4-oxa-5-azahomoadamantane and FeCl for aerobic oxidative synthesis of benzimidazoles from primary amines and o-phenylenediamine is presented. This process uses O as economic and green oxidant and water as green solvent, tolerates a wide range of substrates, and can afford the target products in moderate to excellent yields. [ABSTRACT FROM AUTHOR]