Organic Bromide Research Articles

Atom Transfer Radical Addition via Dual Photoredox/Manganese Catalytic System

Atom transfer radical addition of bromonitromethane and 1,2-dibromotetrafluoroethane to alkenes is described. The reaction is performed under blue light irradiation using two catalysts: 4CzIPN and manganese (II) bromide. The cyanoarene photocatalyst serves for the redox activation of starting organic bromide, while the manganese salt facilitates the trapping of the alkyl radical with the formation of the carbon–bromine bond.

Organic Bromide Salts Interface Modification for High‐Efficiency Perovskite Solar Cells with Printed Carbon Electrode

Perovskite solar cells (PSCs) using carbon as the counter electrode fabricated through a low‐temperature full solution‐process method can significantly simplify the preparation process and reduce production cost. Herein, a high‐performance PSC is presented with printed carbon electrode and dopant‐free poly(3‐hexylthiophene) (P3HT) is employed as hole transport materials. Different organic bromide salts are employed to modify the perovskite/P3HT interface to further enhance the performance. As a result, methylammonium bromide (MABr) modification significantly enhances the device open‐voltage (Voc) and fill factor (FF) by reducing interface defects and facilitates charge transport. A champion power conversion efficiency (PCE) of 19.22% (Voc of 1.118 V, FF of 0.765, and short‐circuit current of 22.48 mA cm−2) is achieved with MABr modification. The unencapsulated devices maintain 96% of the initial efficiency after storage for 3600 h and 88% after thermal treatment at 70 °C for 1200 h. Additionally, perovskite solar modules are also prepared based on printing and interface passivation route with PCE reaches 13.20%. These results represent an important progress in the enhancement of device PCE and up‐scaling of PSCs with cost‐effective, stable, and printed carbon electrode.

Organic bromide solutions-processed all-inorganic perovskite for efficient and stable photovoltaics

All-inorganic CsPbI3-x Br x perovskites with appropriate band gap is an attractive semiconductor material for solar applications, whereas their phase stability plays a key role in high-efficiency perovskite solar cells (PSCs). Their device performance was severely constrained by defects, here we found that the promising phenylpropylamine bromide (PPABr) as a simple additive can effectively influence the crystallization kinetics and produce a bifunctional treatment of perovskite, Br ion doping, and organic cation surface passivation. The PPABr treatment has essentially little influence on the light absorption capacity of CsPbI3-x Br x , the band gap is somewhat widened, and the surface hydrophobicity and phase stability are enhanced. CsPbI3-x Br x perovskites treated with PPABr have altered interfacial properties and obtained better interfacial contact, resulting in improved charge extraction and decreased charge recombination. Furthermore, 2.5 mol% PPABr treated CsPbI3-x Br x -based PSCs exhibited repeatable photovoltaic performance with a maximum efficiency of 13.14%. Within 150 h under air circumstances, the PCE attenuation is controlled to within 5% during the test. Hence, passivating inorganic perovskite using organic bromides PPABr is a novel and promising strategy for developing stable, high-performance solar cells.

The Organic Bromide Sources Adjusting the Shape and Band Structures of BiOBr Nanosheets for Enhanced Photodegradation Performances of BPA

Bismuth oxybromide (BiOBr) nanosheets were prepared by employing organic bromide sources. In the presence of organic bromide sources, the effects of different conditions on the band structure, shape, size, and light responses of BiOBr nanosheets were examined. The reaction conditions, including different types of organic bromide sources, solvent, concentration, temperature, and time, were examined regarding the formation of BiOBr nanosheets. Then, the photocatalytic performances of different BiOBr nanosheets were also examined. Especially, the BiOBr nanosheets obtained from the addition of over 2 mmol of tetramethyl ammonium bromide (TMAB) in mannitol or EG at a higher temperature and longer reaction time showed superior photocatalytic activity. The enhanced photocatalytic performance of bisphenol A over these BiOBr nanosheets was achieved within 50 min due to efficient charge transfer and separation.

α-Amino Radical Halogen Atom Transfer Agents for Metallaphotoredox-Catalyzed Cross-Electrophile Couplings of Distinct Organic Halides.

α‐Amino radicals from simple tertiary amines were employed as halogen atom transfer (XAT) agents in metallaphotoredox catalysis for cross‐electrophile couplings of organic bromides with organic iodides. This XAT strategy proved to be efficient for the generation of carbon radicals from a range of partners (alkyl, aryl, alkenyl, and alkynyl iodides). The reactivities of these radical intermediates were captured by nickel catalysis with organobromides including aryl, heteroaryl, alkenyl, and alkyl bromides, enabling six diverse C−C bond formations. Classic named reactions including Negishi, Suzuki, Heck, and Sonogashira reactions were readily achieved in a net‐reductive fashion under mild conditions. More importantly, the cross coupling was viable with either organic bromide or iodide as limiting reactant based on the availability of substrates, which is beneficial to the late‐stage functionalization of complex molecules. The scalability of this method in batch and flow was investigated, further demonstrating its applicability.

Suppressed Halide Segregation and Defects in Wide Bandgap Perovskite Solar Cells Enabled by Doping Organic Bromide Salt with Moderate Chain Length

Suppressed Halide Segregation and Defects in Wide Bandgap Perovskite Solar Cells Enabled by Doping Organic Bromide Salt with Moderate Chain Length

Organic bromide-assisted one-pot synthesis of Bi2S3 nanorods using DMSO as a sulfur supply

Exploiting dimethyl sulfoxide (DMSO) as both a solvent and a sulfur source, Bi2S3 nanorods are synthesized via a simple solvothermal method in the presence of an organic bromide.

Efficient ionic functionalization of metal-organic frameworks for efficient addition of carbon dioxide to epoxides

The use of homogeneous and polluting halides as nucleophilic cocatalysts lowers the economy and benignity of the CO 2 -epoxide cycloaddition over heterogeneous Lewis-acid catalysts like metal-organic frameworks (MOFs). Creating net positive charge at frameworks is a reasonable strategy to heterogenize halide anions within MOFs, but it is still challenging to achieve high halide loading while keeping adequate porosity. In this article, we report a facile approach to ionic MOFs with high halide content and improved catalytic activity. The catalysts were prepared by reacting azide-tagged MIL-101 with alkyne-tagged organic bromide salts. The efficient azide–alkyne click reaction within the mesoporous MOF allows quantitative cationization of the linkers, and the resultant bifunctional ionic MOFs contain one halide ion per metal center to the benefit of the cooperative catalysis. Catalytic studies suggest that the effects of varying the cationic groups and halide anions in the confined ionic space are different from those observed for homogeneous organic halides. The highest catalytic activity was demonstrated for the MOF having the smallest cationic group (quaternized trimethyl ammonium) and the intermediately nucleophilic halide (Br − ). The catalyst also outperforms the ionic MOF catalysts reported prior to this work. • A series of ionic MOFs were prepared by facile alkyne-azide click reactions. • The MOFs contain one halide per metal to the benefit of cooperative catalysis. • The confined ionic space changes the effects of cationic groups and halide anions. • The optimal catalyst, MIL-101-tz-TMA-Br, outperforms previous ionic MOF catalysts.

Adsorption of reactive yellow BF-3R dye by CTABr modified zeolite NaY

Textile industries generate effluents composed of organic salts and complexes from dyes not fixed on fabrics, or not degraded by the inefficiency of conventional treatment processes, which represents a high potential for environmental impact due to inadequate disposal of the generated effluent. Zeolites are porous materials that have a three-dimensional structure containing tetrahedrals of AlO4 e SiO4 which can be modified to improve its properties. The adsorption process using zeolites as adsorbents can be considered an excellent economic physical treatment to solve or minimize such a problem. This work presents an experimental study focusing on the preparation and characterization of zeolite NaY and modified with organic surfactant cetyltrimethylammonium bromide (CTABr) intended to be used as adsorbent in the process of removing yellow dye BF-3R in dye-water system batch system. The samples were characterized by X-ray diffraction (XRD), Infrared spectroscopy (IR) and thermogravimetry (TG). The effect of process parameter such as pH was studied. Results revealed that even though the modified cetyltrimethylammonium bromide organic surfactant (CTABr) did not cause alterations on the zeolite NaY structure. The IR results revealed that CTABr was successfully incorporated to zeolite NaY structure. The best conditions were established with respect to pH to saturate the available sites located on the zeolite NaY and NaY_CTABr surface. The maximum adsorption capacities were 3.35 and mg/g for dye 5.35 using as-synthesized zeolite NaY and CTABr modified zeolite NaY. Modified zeolites are excellent adsorbents for removing reactive dyes from industrial wastewater.

Interplay between non-covalent interactions in 1D supramolecular polymers based on 1,4-bis(iodoethynyl)benzene.

A study of the solution-phase, solid-state structures of halogen-bonded co-crystals of 1,4-bis(iodoethynyl)benzene (p-BIB) with three salts, namely, decyltrimethylammonium bromide (DTMABr), tetrapropylammonium bromide (TPABr), and tetrabutylammonium bromide (TBABr), has been carried out, along with theoretical calculations. Isothermal titration calorimetry (ITC) showed that the binding constant of bromide with p-BIB in THF is not strongly dependent on the cation, and that the entropic term clearly dominates the enthalpic one in the free energy of binding. In the three crystal structures, the bromide anion acts as a doubly connected node for halogen bonding interactions, which results in linear or angular open chains. The intrachain angles (IBr-I) of the 1D supramolecular polymers based on p-BIB depend on the geometry and size of the cation and vary from 180° for DMTABr to 75° for TBABr. Non-covalent interaction (NCI) analysis of selected motifs and optimized crystals demonstrates that the balance between halogen bonds, hydrogen bonds, and van der Waals interactions, especially type-I halogenhalogen contacts, determines the crystal structures.

Metal-free regioselective bromination of imidazo-heteroarenes: the dual role of an organic bromide salt in electrocatalysis

This paper presents an organo-electrocatalysis method which demonstrates the dual role of an organic bromide salt as a brominating agent and as an electrolyte for the regioselective bromination of imidazo heteroaromatic motifs.

DÜŞÜK BROMÜR VE ORGANİK MADDE İÇEREN SU KAYNAKLARI İÇİN ÖN DEZENFEKTAN SEÇİMİNDE ÇOK ÖLÇÜTLÜ KARAR VERME METOTLARININ UYGULANMASI

Deciding among many good or bad options is one of the most difficult situations for managers and administrators. The types of pre-disinfectants to be selected for use in drinking water resources are also quite high and this makes the choice difficult. In this study, “Multi Criteria Decision Making Methods” were used in order to facilitate decision making for the selection of pre-disinfectants for water sources with low organic matter and low bromide concentration considering the general condition of our country's water resources. An analysis method consisting of the combination of “Analytic Hierarchy Process” (AHP) and “Technique for Order Preference by Similarity to Ideal Solution” (TOPSIS) techniques was used in the study. In this context, a systematic study was carried out by determining 6 criteria (Residual DisinfectantMicroorganism Removal-Equipment Requirement-Security Concerns-pH Dependence-Health Effects) and 6 sub-criteria (Chlorine (Gases)-Chlorine (liquid)-Ozone-Chlorine Dioxide-Chloramine-UV) and making use of expert opinions and literature knowledge. Due to the advantages such as high residual resistance, low equipment requirement, low pH dependency and relatively low health concerns, chlorine gas is determined as the best pre-disinfectant, while UV is the last disinfectant to be preferred.

In-situ debromination mechanism based on self-activation and catalysis of Ca(OH)2 during pyrolysis of waste printed circuit boards

Completely and deeply removed bromide from waste printed circuit boards (WPCBs) is necessary due to their toxicity and carcinogenicity. To achieve this purpose, calcium hydroxide (Ca(OH)2) as a debromination agent was added during pyrolysis process of WPCBs. The results showed that hydrogen bromide (HBr), 4-bromophenol, 2-bromophenol and 2,4-dibromophenol were the main bromide species in pyrolysis products. The Ca(OH)2 plays a significant role for removing HBr and organic bromide, but not affects products yield. Optimal removal efficiency for 4-bromophenol, 2-bromophenol and 2,4-dibromophenol reached 87.5 %, 74.6 % and 54.5 %, respectively. And debromination efficiency was related to the steric hindrance caused by bromide atoms. The Ca(OH)2 can be activated by captured HBr and its thermal decomposition. And the newly-generated calcium bromide and calcium oxide significantly facilitate debromination due to their high surface energy and reactivity. The debromination mechanism was clarified by experiments coupled with computational chemistry: the coordination of bromide and calcium to form [Ph-Br···Ca2+] or [Ph-Br···Caatom]. Then, electrons were delivered form bromide atom to Ca2+ or Caatom, which resulted in the stretch and weaken the C-Br bond. Hence, the C-Br bond was more easily to break. This work can provide support for designing novel and efficient debromination agents applied for high-temperature system.

Size Effect in Nanocomposites Based on Molecular Ferroelectric Diisopropylammonium Bromide

We present the results of studies of the dielectric properties of nanocomposites based on Al2O3 oxide films with a pore size of 330 and 60 nm with particles of an organic ferroelectric diisopropylammonium bromide (C6H16BrN, DIPAB) introduced into the pores, aimed at determining the size dependences of phase transition parameters. A shift in the phase transition to low temperatures and diffusion of the transition are found, which become more significant for smaller pores. A broadening of the temperature hysteresis of the dielectric constant of nanocomposites during the phase transition was also observed. The decrease in the phase transition temperature in nanocomposites with DIPAB nanoparticles is consistent with theoretical models of the size effects on the structural phase transition.

Copper(II)-phenanthroline hybrid material as efficient catalyst for the multicomponent synthesis of 1,2,3-triazoles via sequential azide formation/1,3-dipolar cycloaddition

A copper(II)-phenanthroline hybrid material based on the SBA-15 architecture was prepared using a two-step synthesis through co-condensation of 5-[N,N-bis-3-(triethoxysilyl)propyl]ureyl-1,10-phenanthroline with tetraethoxysilane, followed by coordination of Cu(OAc)2. The obtained hybrid material, Cu(II)phen@SBA-15, was fully characterized, at each stage of the preparation, by means of bulk and molecular techniques to assess both textural and structural catalyst features using XRD, XPS, EPR, HRTEM, SEM, solid-state NMR UV–vis and IR analytical tools. The characterization results altogether confirmed the structural integrity of the mesoporous host and the successful anchoring of the copper-phenanthroline complex as discrete mononuclear Cu(II)L species. The catalytic performances of Cu(II)phen@SBA-15 were evaluated in the aqueous 1,3-dipolar cycloaddition of azides with alkynes using a multicomponent one-pot synthesis where organic azides were produced in situ from organic bromide (or aryl diazonium salts or epoxides), providing for safer synthetic technologies. The catalyst proved to be highly active under mild reaction conditions (0.5mol%, 70°C) over a broad range of substrates, providing 1,4-disubstituted-1,2,3-triazoles in high yields.

Experimental Investigation of Trihalomethane Formation and Its Modeling in Drinking Waters

Chlorine is commonly used as a disinfectant to eradicate pathogenic organisms in drinking waters. However, when water containing the organic precursor compounds is chlorinated, disinfection by-products such as trihalomethanes and halo acetic acids may be generated. Due to the adverse health effects of disinfection by-products on human being, many industrialized countries have developed stringent regulations for the control of disinfection by-products. Meanwhile, some international regulatory agencies worldwide have set maximum contaminant levels for disinfection by-products like trihalomethanes. The United States environmental protection agency (USEPA) and European Union (EC) have set to the maximum contaminant levels of four trihalomethane species (chloroform, dichlorobromomethane, dibromochloromethane and bromoform) of 80 μg/L. The limit for trihalomethanes is 100 μg/L in Turkey. The formation of disinfection by-products depends on many factors such as solution pH, temperature, the concentration and content of natural organic matter, disinfectant dose, bromide concentration and reaction time. For instance the yield of trihalomethanes has been observed to increase with increasing pH. Furthermore, several surrogate parameters (total organic carbon, UV254 and specific ultraviolet absorbance) have been used to represent the reactivity of natural organic matter (NOM) and disinfection Experimental Investigation of Trihalomethane Formation and Its Modeling in Drinking Waters

DETERMINATION AND VALIDATION OF INORGANIC BROMIDE BY GAS CHROMATOGRAPHY IN SEVERAL FOODS

An analytical method for determination of inorganic bromide in cereals, herbs, fruits and vegetables had been validated. The comminuted samples are suspended in an acidified aqueous solution of propylene oxide, with bromide being simultaneously extracted. Organic bromide is converted to mixture of 1-bromo-2-propanol and 2-bromo-1-propanol and partitioned by ethyl acetate and then determined by GC-ECD without further cleanup, the analytical parameters of the method such as limit of quantification and linearity have been investigated. The limit of quantification is found to be 2 mg/kg for dry samples and 0.2mg/kg for fresh samples. The method showed to be linear up to 100 mg/kg. The average recoveries at different concentration levels on the fresh samples and dry samples ranged from 84 to113%. The reproducibility expressed as relative standard deviation was less than 12.8 % for dry samples and 11.6 % for fresh samples. The measurement uncertainty expressed as expanded uncertainity in terms of relative standard deviation at 95 % confidence level was found to be within the range ±33%

Application of a Magnetic Resin (MIEX) in Raw Water

The objective of this research was to compare enhanced coagulation with anion exchange for removal of natural organic matter (NOM) and bromide. Treatment with a magnetic ion exchange resin (MIEX) was the primary focus of this study. The performance of the magnetic ion exchange resin,MIEX, in the treatment of raw water was investigated. MIEX can effectively remove UV-absorbing substances DOC. The removal of organic substances is accompanied by the elimination of other undesirable components, such as nitrogen and phosphorus. The optimal process parameters are at resin doses of 5-10 mL L1and contact time of 10-15 min, as determined via jartests. Based on this study, MIEX treatment is a suitable and efficient pretreatment method for the removal of extra dissolved organic matters and nitrates in raw water .

Purification Raw Water by Magnetic Resin (MIEX)

The objective of this research was to compare enhanced coagulation with anion exchange for removal of natural organic matter (NOM) and bromide. Treatment with a magnetic ion exchange resin (MIEX) was the primary focus of this study. The performance of the magnetic ion exchange resin,MIEX, in the treatment of raw water was investigated. MIEX can effectively remove UV-absorbing substances DOC. The removal of organic substances is accompanied by the elimination of other undesirable components, such as nitrogen and phosphorus. The optimal process parameters are at resin doses of 5-10 mL L1and contact time of 10-15 min, as determined via jartests. Based on this study, MIEX treatment is a suitable and efficient pretreatment method for the removal of extra dissolved organic matters and nitrates in raw water .

Reaction of 1Н,2Н,3Н,4Н-pyrido[4,3-d]pyrimidinium bromide derivatives with molecular iodine: Comparative structure and spectroscopic analysis

Abstract New salts C 27 H 22 N 3 O 2 BrI 2 ( 1 ) and C 27 H 19 N 3 O 2 Br 4 I 2 ·2CHCl 3 ·2H 2 O ( 2 ) were synthesized by the iodination of derivatives of 1,3-dimethyl-2,4-dioxo-5,6,7-R-1Н,2Н,3Н,4Н-pyrido[4,3- d ]pyrimidinium bromide (R = phenyl ( 1a ), p -bromphenyl ( 2a )) with an equimolar amount of iodine. The positive values of enthalpy (Δ H ) and entropy (Δ S ) indicate that the complexation of organic bromide and iodine molecule in chloroform solution is mainly entropically driven. The molecular and crystal structures ( 1 ) and ( 2 ) are studied by X-ray diffraction analysis. The structure of diiodinebromide 1 is composed of separate almost liner BrI 2 - and 1,3-dimethyl-2,4-dioxo-5,6,7-thriphenyl-1Н,2Н,3Н,4Н-pyrido[4,3- d ]pyrimidinium cation. The crystal structure 2 is built up of alternate layers of ( C 27 H 19 N 3 O 2 Br 3 + ) ( I 3 - ) ( A ) and (Br 2 I − )(СHСl 3 ) ( B ), connected to each other by hydrogen bonds Br ( Br 2 I - ) ⋯ H ( C 27 H 19 N 3 O 2 Br 3 + ) . The formation of the ions I 3 - and Br 2 I − occurs via the disproportionation of I 2 Br − under the action of solvent on C 27 H 19 N 3 O 2 Br 4 I 2 ·2CHCl 3 ·2H 2 O ( 2 ) crystallization.