Inorganic Bromide Research Articles

A Review on the Some Biological Activities of the Hydantoin Derivatives

Hydantoin derivatives are commonly used anticonvulsants. In general, they are effective for partial-onset seizures and tonic-clonic seizures, but not for absence seizures. Phenytoin is the most important drug in this group, and other drugs, ethotoin, and mephenytoin, are also commonly used to treat epilepsy. Prodrugs such as derivatives have been created. Phenytoin is effective in some cases of trigeminal neuralgia and related neuralgia. Phenytoin is also used to treat arrhythmias. Hydantoins or glycolylureas are heterocyclic organic compounds with the formula CH2C(O)NHC(O)NH. It is a colorless solid formed by the reaction of glycolic acid and urea. It is an oxidized derivative of imidazolidine. In a more general sense, hydantoins can refer to groups and classes of compounds that share the same ring structure as their parent. For example, phenytoin (see below) has two phenyl groups substituted at the 5th carbon of the hydantoin molecule. Actual chemotherapy for epilepsy dates back to the 1850s when "inorganic bromides" were introduced. However, it is worth noting that around the 1920s, the therapeutic and beneficial use of 'phenobarbital' usheredin an era of meaningful treatment of epilepsy. Hydantoin ring chemistry is the synthesis of rings by various methods and their applications in the medical field. Previous descriptions of hydantoin-containing compounds have broad pharmacological and biological activities, including anticancer, anti-inflammatory, anti-immune, antimetabolite, antioxidant, antibacterial, CNS-related, anticonvulsant, antitussive, and cytoprotective activities.
 Keywords: Hydantoin derivatives, anticonvulsants, partial-onset seizures and tonic-clonic seizures

Investigation of structural, optical and electrical conductivity of a new organic inorganic bromide: [C12H17N2]2ZnBr4.

A new organic-inorganic hybrid, namely the [C12H17N2]2ZnBr4 compound, has been synthesized and studied by single-crystal X-ray diffraction and optical and complex impedance spectroscopy. It crystallized in the centrosymmetric P21/n space group at room temperature. The asymmetric unit is constituted by [ZnBr4]2- anions, showing slightly distorted tetrahedral geometry, surrounded by four organic (C12H17N2)+ cations. The crystal packing is stabilized by N-H⋯Br and C-H⋯Br hydrogen bonds arranged in a three-dimensional network. The optical absorption measurement confirms the semiconductor nature with a band gap of around 3.94 eV. Additionally, the analysis of Nyquist plots (-Z'' vs. Z') shows that the electrical properties of the material are heavily dependent on frequency and temperature, indicating a relaxation phenomenon and semiconductor-type behavior. Reduction in Z' was observed as a function of temperature and frequency which indicates an increase in ac conductivity and the negative temperature coefficient of resistance. The frequency dependent plots of (-Z'') show that the electrical relaxation is non-Debye in nature. The ac conductivity spectrum obeys Jonscher's universal power law. The Correlated barrier hopping model CBH has been suggested to agree with the conduction mechanism of σ ac for the [C12H17N2]2ZnBr4 compound.

Mechanistic insights into catalysis of in-situ iron on pyrolysis of waste printed circuit boards: Comparative study of kinetics, products, and reaction mechanism

Pyrolysis is a potential recovery method for waste printed circuit boards (WPCBs), but the organic brominated products are toxic and hazardous. Iron has been used as a catalyst for debromination from pyrolysis oil, but the effects of in-situ iron on WPCBs pyrolysis is still not well understood. Herein, the pyrolysis mechanism for laminates of PCBs in the absence and presence of iron was studied via analyzing pyrolysis characteristics, kinetics, and products. According to the thermogravimetry experiments, pyrolysis of all samples could be divided into four stages, and iron accelerated the pyrolysis reaction by decreasing the activation energy as calculated using the Starink method. Volatiles released during the heating process were continuously determined by TG-FTIR-MS, and products generated at different pyrolysis temperatures were collected and characterized. The obtained results exhibited that iron promoted the generation of gaseous products and facilitated the conversion of organic bromides to inorganic bromides. Therefore, retaining iron was beneficial to energy saving and environmental protection for WPCBs pyrolysis. In addition, the decomposition mechanisms of brominated epoxy resin with and without iron were proposed. This work would contribute to the improvement and application of WPCBs pyrolysis technology.

Mechanochemical destruction and mineralization of solid-phase hexabromocyclododecane assisted by microscale zero-valent aluminum

Hexabromocyclododecane (HBCD) has been listed in Annex A of the Stockholm Convention as a persistent and bio-accumulative chemical. While HBCD is often present in the solid form for its low solubility, cost-effective technologies have been lacking for the degradation of solid-phase HBCD. In this work, mechanochemical (MC) destruction of high-energy ball milling was employed for direct destruction of solid-phase HBCD, where a strong reducer, microscale zero-valent aluminum (mZVAl), was used as the co-milling agent. The new mZVAl-assisted MC process achieved complete debromination and mineralization of HBCD within 3 h milling. The optimal operating parameters were determined, including the milling atmosphere, the milling speed, the mZVAl-to-HBCD molar ratio, and the ball-to-mZVAl mass ratio. Fourier transform infrared spectrometry and Raman analyses revealed that the organic structures of HBCD were destroyed and organic bromine was completely converted into inorganic bromide, accompanied by the generation of amorphous and graphite carbon. Analysis of the milled samples by GC–MS demonstrated the absence of obvious organic matter after MC treatment, also indicating the complete degradation and conversion of HBCD to inorganic compounds. Further X-ray photoelectron spectroscopic analysis indicates that the fresh surface of mZVAl was generated upon the MC treatment, and Al(0) served as a strong reducing agent (e-donor) for reductive debromination and destruction of the carbon skeleton. The mZVAl-assisted MC milling appears promising as a non-combustion approach for effective destruction and carbonization/mineralization of solid-phase HBCD or potentially other persistent organic pollutants.

Dynamic Control of Self-Assembly of Amphiphilic Conjugated Alkenes in Water by Reactions.

Nature sets a great example of how to precisely control self-assembly to obtain distinct structures upon external stimuli and perform specific functions to sustain important biological tasks. In the present study, we report the design and control of self-assembly of an amphiphilic conjugated alkene in water. The morphologies of the self-assembled structures are highly dependent on the anions. The hydrophilic tosylate group can trigger the formation of nanotubes, while the less-hydrophilic inorganic bromide generates vesicles. The interchange of the two different structures can be controlled by employing different anions combined with a couple of reactions that act as signals. The result shown here provides an important tool for manipulating self-assembled behaviors in water and paves the way toward more complex systems.

Synthesis, structural and electrical characterization of a new organic inorganic bromide: [(C3H7)4N]2CoBr4.

A new organic inorganic hybrid [TPA]2CoBr4, where TPA = [(C3H7)4N]+ (i.e., tetra-propyl-ammonium) compound has been synthesized by slow evaporation method at room temperature. Single crystal X-ray diffraction (SC-XRD), X-ray powder diffraction (XRPD), thermal analyses, vibrational and complex impedance spectroscopy have been used to characterize both structural, thermal, electrical properties. [TPA]2CoBr4 crystallizes in the monoclinic system (C2/c space group) with the following cell parameters: a = 33.145 (5) Å, b = 14.234 (3) Å, c = 15.081 (2) Å and β = 110.207 (5)°. In the crystal structure, the organic TPA cations which form layers stacked along the a-axis, are separated from each other by inorganic tetrahedral [CoBr4]2− anions. The XRPD pattern confirms both the high purity of the sample and the crystalline nature of the powder. The differential scanning calorimetry (DSC) analysis shows an endothermic peak at 394 K upon heating which is ascribed to a structural phase transition since no decomposition of the titled compound is evidenced by thermogravimetric analysis. The ac conductivity and the dielectric properties confirm the presence of the phase transition. At the structural phase transition around 394 K, a change from a quantum mechanical tunneling to a correlated barrier hopping conduction models is determined from the temperature dependence of the exponent s of the Jonscher's power law. The analysis of complex impedance spectra shows that the electrical properties of the material are heavily dependent on frequency and temperature, indicating a relaxation phenomenon and semiconductor-type behavior. One single semicircle is detectable in the Nyquist plots of the complex impedance spectra which can be satisfactorily fitted with a combination R//CPE elements assigned to the bulk response. This behavior suggests that the sample is electrically homogeneous. Capacitance analysis proves the high effective permittivity at radio frequencies in the sample.

Eco-friendly and low-cost removal of bromine from waste printed circuit board smelting ash by mechano-chemical leaching

This work introduces an eco-friendly, efficient, and low-cost approach for the removal of hazardous inorganic bromides and the recovery of a high-purity NaBr product from waste printed circuit board smelting ash via a mechano-chemical technology.

A new mechanism and kinetic analysis for the efficient conversion of inorganic bromide in waste printed circuit board smelting ash via traditional sulfated roasting

The waste printed circuit board smelting ash (WPCB-SA) produced in the waste printed circuit board smelting process is a hazardous material that not only contains valuable metals, but also contains a large amount of toxic and harmful inorganic bromides. The utilization of metals has received considerable attention in previous studies, but the recovery of hazardous bromides requires further study. In this article, a new idea of converting inorganic bromine in WPCB-SA by traditional sulfated roasting is proposed. Debromination kinetics under simulated experimental conditions are discussed, and kinetic equations are established. The kinetic results show that during low-temperature sulfated roasting, the conversion of Br in CuBr and PbBr2 conforms to the chemical reaction diffusion model and diffusion control the product layer model, respectively. A possible reaction mechanism is also proposed. Our research shows that the conversion of Br in CuBr is divided into three processes: covalent bond decomposition, hydrogen ion form acid, copper ion form salt, and HBr oxidation conversion, whereas the conversion of Br in PbBr2 is divided into two processes: sulfuric acid ionization, lead ion form salt and HBr oxidation conversion. This work provides the theoretical basis for the improvement and application of inorganic bromide recovery technology in WPCB-SA.

Selective carboxylation of reactive benzylic C-H bonds by a hypervalent iodine(III)/inorganic bromide oxidation system.

An oxidation system comprising phenyliodine(III) diacetate (PIDA) and iodosobenzene with inorganic bromide, i.e., sodium bromide, in an organic solvent led to the direct introduction of carboxylic acids into benzylic C–H bonds under mild conditions. The unique radical species, generated by the homolytic cleavage of the labile I(III)–Br bond of the in situ-formed bromo-λ3-iodane, initiated benzylic carboxylation with a high degree of selectivity for the secondary benzylic position.

Survival and development of embryos of <i>Gallus gallus domesticus</i> treated with inorganic bromide

The range of bromide (Br-) in groundwater sources surveyed in South Africa is 0 - 18.4 mg/L. The research aimed to establish chicken embryo sensitivity to a range of Br- treatments (mg/L) injected into fertilised Ross-308 eggs in three phases: (1) five eggs injected with 10 mg Br-/L; (2) 45 eggs divided into groups and injected with 0, 1 and 5 mg Br-/L; (3) 148 eggs divided into groups injected with 0, 0.01, 0.05, 0.5, and 1 mg Br-/L. Incubation was at standard conditions. Breakout analysis was done at various stages of incubation. The mass of the embryo and of the heart, liver and brain was measured at Day 20. Statistical analysis used Statistical Analyses System® software FREQ procedure to determine the chi-square goodness-of-fit test for percentages of live or dead embryos within and between treatments. The GLM procedure was applied to test for differences in relative organ mass (g) between treatments using F-test. The results showed: (1) 10 mg Br-/L is toxic; (2) Br- is lethal to embryos at concentrations >1 mg/L and toxic at 1 mg/L; and (3) embryo survival was significantly negatively correlated (R2 = -0.92) with increasing Br- concentrations. Concentrations >0.5 mg Br-/L showed greater risk on differential development. Concentrations >0.01 mg Br-/L showed potentially severe effects on developing embryos. The heart showed the greatest relative growth response followed by the brain. The no observed adverse effect level target water quality range (NOAEL-TWQR) in developing chicken embryos was 0 - 0.01 mg/L.Keywords: Bromine, embryo model, halogens, maximum residue level, toxicity, water quality

Environmental emission analysis of a waste printed circuit board-derived adsorbent production process

The short life span of electrical and electronic equipments (EEE) produces a tremendous amount of waste electrical and electronic equipments (WEEE) globally at an overwhelming rate. Currently, the recycling of waste printed circuit board (WPCB) is an emerging and sensitive environmental issue since traditional treatment methods have been proved to be inappropriate. Also, the recovery of valuable components from WPCB is limited by the environmental emissions from the recycling process, which have been seriously neglected by the research community before. To analyze the environmental emission impacts and set evaluation criteria, a newly developed aluminosilicate adsorbent production process is discussed in this work. It is proved to be capable to recycle the NMF of WPCB as the feedstock of the functionalization process. Besides, the mass balance of reaction reagents, bromide and carbon were established with clear pathways and destinations by various analytical chemistry methods. The debromination process in functionalization significantly reduced the total toxicity by giving inorganic bromide and bisphenol A (BPA) as two main products. The results confirm this process to be an environmentally friendly process which can provide a basis for evaluating recycling processes.

Abiotic Bromination of Soil Organic Matter.

Biogeochemical transformations of plant-derived soil organic matter (SOM) involve complex abiotic and microbially mediated reactions. One such reaction is halogenation, which occurs naturally in the soil environment and has been associated with enzymatic activity of decomposer organisms. Building on a recent finding that naturally produced organobromine is ubiquitous in SOM, we hypothesized that inorganic bromide could be subject to abiotic oxidations resulting in bromination of SOM. Through lab-based degradation treatments of plant material and soil humus, we have shown that abiotic bromination of particulate organic matter occurs in the presence of a range of inorganic oxidants, including hydrogen peroxide and assorted forms of ferric iron, producing both aliphatic and aromatic forms of organobromine. Bromination of oak and pine litter is limited primarily by bromide concentration. Fresh plant material is more susceptible to bromination than decayed litter and soil humus, due to a labile pool of mainly aliphatic compounds that break down during early stages of SOM formation. As the first evidence of abiotic bromination of particulate SOM, this study identifies a mechanistic source of the natural organobromine in humic substances and the soil organic horizon. Formation of organobromine through oxidative treatments of plant material also provides insights into the relative stability of aromatic and aliphatic components of SOM.

Transformation of bromide in thermo activated persulfate oxidation processes

Sulfate radicals (SO4−·) are applied to degrade various organic pollutants. Due to its high oxidative potential, SO4−· is presumed to be able to transform bromide to reactive bromine species that can react with natural organic matter subsequently to form brominated products including brominated disinfection by-products (Br-DBPs). This research was designed to investigate the transformation of bromide in thermo activated persulfate oxidation process in the presence of humic acid (HA). Significant formation of bromoform and bromoacetic acids was verified. Their formation was attributed to the reactions of HA and reactive bromine species including Br·, Br2−· HOBr−, and free bromine resulted from the oxidation of bromide by SO4−·. Yields of Br-DBPs increased monotonically at persulfate concentration of 1.0 mM and working temperature of 70 °C. However, the time-depended formation exhibited an increasing and the decreasing profile when persulfate was 5.0 mM, suggesting further degradation of organic bromine. HPLC/ICP-MS analysis demonstrated that the organic bromine was eventually transformed to bromate at this condition. Thus, a transformation scheme was proposed in which the bromine could be recycled multiple times between inorganic bromide and organic bromine before being finally transformed to bromate. This is the first study that reveals the comprehensive transformation map of bromine in SO4−· based reaction systems, which should be taken into consideration when such technologies are used to eliminate contamination in real practice.

Visible Light Catalytic Degradation of Aniline Wastewater over Multishaped BiOBr Microcrystals

The photooxidation process of aniline-containing simulated wastewater under visible light irradiation over BiOBr microcrystal grains with different shapes was studied. The distinctive surface microstructures of the BiOBr microcrystals, like clustered flower petals and quadrate lamellas, were produced by using imidazole ionic liquid and inorganic bromide as Br sources and by solvothermal and hydrothermal route, respectively. The ionic liquid not only can impact the products’ morphology, but also can largely improve the photocatalytic activity of the BiOBr microcrystals due to the soft templating effect. The top degradation ratio of the aniline wastewater photocatalyzed by lamellar BiOBr crystals is 23.71%, but the equivalent value photocatalyzed by flower petal-like BiOBr crystals is almost twice as much; that is, it reaches 46.51%. The photodegradation effect and mechanism over differently shaped BiOBr microcrystals have been compared.

A novel process for the removal of bromine from styrene polymers containing brominated flame retardant

High-impact polystyrene (HIPS) is one of the main plastic fractions of waste electric and electronic equipment (WEEE). Although recycling of this material is desirable, the presence of brominated flame retardants requires the removal of bromine prior to further treatment steps in order to avoid deterioration. In this study, a new method was developed for the removal of bromine from the polymer without destroying the polymer matrix. Organic bromine from the flame retardant (decabromodiphenyl ethane) was converted into inorganic bromide using a solution of NaOH in ethylene glycol (NaOH(EG)). Using a stirred flask as the reaction vessel, a debromination ratio of 42% was obtained at 190 °C regardless of the NaOH concentration. The same reaction in a ball mill reactor reduced the bromine content in the HIPS to 0.02 wt%. The conversion of organic bromine into inorganic bromide reached 98%. Degradation products from the flame retardant were identified using high performance liquid chromatography coupled with mass spectrometry. In both the flask and ball mill reactor, the reaction was diffusion controlled with an activation energy of about 205 kJ mol−1. The thermal stability of the residual plastic was enhanced during the treatment, which opens up the possibility of reusing waste HIPS by mechanical recycling.

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%

A Combined Theoretical and Cambridge Structural Database Study of π-Hole Pnicogen Bonding Complexes between Electron Rich Molecules and Both Nitro Compounds and Inorganic Bromides (YO2Br, Y = N, P, and As)

Quantum calculations at the DFT-D3/def2-TZVPD level of theory have been used to examine complexes between O2YBr (Y═N, P, and As) molecules and several Lewis bases, that is, NH3, H2O, and HF. The interactions of the lone pair of the ammonia, water, and hydrogen fluoride with the σ-hole and π-hole of O2YBr molecules have been considered. In general, the complexes where the Lewis base lone pair interacts with the π-hole are more favorable than those with σ-hole. The nature of the interactions has been characterized with the Bader theory of atoms in molecules (AIM). We have also studied the ability of trifluoronitromethane and nitromethane to interact with anions using their π-hole along with an analysis the Cambridge Structural Database. We have found a large number of hits that provide strong experimental support for ability of the nitryl (-NO2) group to interact with anions and Lewis bases. In some X-ray structures, the π-hole interaction is crucial in the crystal packing and has a strong influence in the solid state architecture of the complexes. Finally, due to the relevance in atmospheric chemistry, we have studied noncovalent σ/π-hole complexes of nitryl bromide with ozone.

Rapid quantitative method for total brominated vegetable oil in soft drinks using ion chromatography

A simple, quantitative and rapid method for total brominated vegetable oil (BVO) using ion chromatography (IC) with suppressed conductivity detection was developed and successfully applied to soft drinks with results expressed as inorganic bromide anion. The procedure involves extraction of BVO with diethyl ether and treatment with zinc dust in a solution of acetic acid, giving recoveries ranging between 92.5 and 98.5%. The calibration curves obtained were linear with correlation coefficients (r 2) of 0.998, a coefficient of variation (CV) of less than 5% and limit of detection (LOD) and limit of quantification (LOQ) of 250 and 750 µg l−1, respectively. The method was successfully applied to the determination of BVO in several commercial soft drinks which were found to contain BVO in the range 1.8–14.510 mg l−1. The method has less sources of error compared to previously published methods.

Natural organobromine in terrestrial ecosystems

Recent studies have shown that bromine undergoes biogeochemical cycling involving natural formation and degradation of organobromine compounds in marine systems. In the terrestrial environment, where background bromine levels tend to be low, the biogeochemistry of this element remains largely unexamined. We traced the path of bromine through plant growth, senescence, and decay of leaf litter on the forest floor. Using sensitive X-ray spectroscopic techniques, we show that all bromine in humified plant material, organic-rich surface soils, and isolated humic substances is bonded to carbon. Analysis of bromide-enriched plants suggests that bromide absorbed by the growing plants ultimately converts to organobromine when the plant litter decays. Application of isolated chloroperoxidase, a halogenating enzyme, to healthy plant material results in extensive bromination, with organobromine formed preferentially over organochlorine. The relative ease of bromide oxidation appears to promote biogeochemical transformations of Br from inorganic to organic forms, leading to its incorporation into soil organic matter through enzymatic processes related to plant litter decomposition. In combination with low concentration and susceptibility to leaching and plant uptake, natural bromination processes lead to the exhaustion of inorganic bromide in surface soils, making organic matter a reservoir of bromine in the terrestrial environment. This study provides the first detailed look into the terrestrial bromine cycle and lays the foundation for future studies of natural organobromine degradation, which may shed light on the fate of anthropogenic organobromine pollutants in the soil environment.

High-precision isotope ratio analysis of inorganic bromide by continuous flow MC-ICPMS

The study proposes a new method for the high-precision determination of bromine isotope ratio in inorganic samples. In the suggested method, inorganic bromide is wet-oxidized into molecular bromine and transferred into the MC-ICPMS by continuous flow of helium. Analysis of natural inorganic bromide samples from various sources revealed identical δ 81Br values within the range of the method uncertainty.