Progress in Analytical Methods of Halogenated Disinfection By-Products

Ensuring the health and safety of drinking water is crucial for both nations and their citizens.Since the 20th century,the disinfection of drinking water,effectively controlling pathogens in water sources,has become one of the significant advances in public health.However,the disinfectants used in the process,such as chlorine and chlorine dioxide,react with natural organic matter in the water to produce disinfection by-products(DBPs).Most of these DBPs contain chlorine,and if the source water contains bromine or iodine,brominated or iodinated DBPs,collectively referred to as Halogenated disinfection byproducts(X-DBPs),are formed.Numerous studies have found that X-DBPs pose potential risks to human health and the environment,leading to widespread concern.Mass spectrometry has become an important means of discovering new types of X-DBPs.This paper focuses on the study of methods for analyzing X-DBPs in drinking water using mass spectrometry.

Textural and compositional variation of mica from the Dexing porphyry Cu deposit:constraints on the behavior of halogens in porphyry systems

The Dexing porphyry deposit is the largest porphyry Cu–Mo–Au deposit in South China.Biotite composition can record the physicochemical conditions and evolution history of magmatic-hydrothermal system.Biotite from the Dexing porphyry deposit could be divided to three types:primary magmatic biotite(Bi-M),hydrothermal altered magmatic biotite(Bi-A)and hydrothermal biotite(Bi-H).The temperature of Bi-M and Bi-H range from 719 to 767℃ and 690 to 727℃,respectively.Both magmatic and hydrothermal biotite have high Fe^(3+)/Fe^(2+)ratios(from 0.18 to 0.24)and XMgvalues(from 0.57 to 0.66),indicating a high oxygen fugacity.BiM has F lower than Bi-A and Bi-H(up to 0.26 wt%),but has Cl(Cl=0.18–0.30 wt%)similar to Bi-A and Bi-H(Cl=0.21–0.35 wt%),suggesting that high Cl/F ratios of early hydrothermal fluid may result from the exsolution from high Cl magma.From potassic alteration zone to phyllic and propylitic alteration zones,Cl decreases with increasing Cu,whereas F increases roughly.Therefore,Cl mostly originate from magma,but enrichment of F possibly results from reaction of fluids and Neoproterozoic strata.Negative correlation between Cl and Cu indicates that Cl might act as an important catalyst during Cu mineralization process.Biotite from Dexing has similar halogen compositions to other porphyry Cu-/Mo deposits in the world.Chlorine contents of hydrothermal fluid may be critical for Cu transportation and enrichment,while consumption of Cl would promote Cu deposition.

Accurate Formulae for the Cross-Section Data for the Radio-Halogen I-123 from Cyclotron Production

123I is the most widely used cyclotron-produced radio-halogen in medical research. In this paper, excitation function formulae for the nuclear reactions of 123I production are introduced. 124Te (p, 2n)123I and 127I (p, 5n)123Xe → 123I nuclear reactions have been studied as a function of the energy of the neutrons. Both two formulae were created using the least squares regression of the experimental cross sections data, which were obtained from the Experimental Nuclear Reaction Data EXFOR Database version of 2023. The proposed formulae were evaluated using two statistical indicators for goodness-of-fit. High agreement was observed between the empirical and experimental results for both nuclear processes.

Quantitative structure－activity study on the reductive dehalogenation potency of the halogenated aromatics

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Risk Points of Flame Retardant Textiles by Halogen and Halogen-Free Laminating Film

This study was to develop the flame retardant (FR) protective clothing which had multifunction such anti-bacterial, UV cut, FR function with water repellent and water vapor permeable laminating textiles for industrial workers. First of all, the FR yarn and FR textiles were developed for this purpose. Second, the comparison analysis between the halogen laminating textiles and halogen-free laminating textiles were tested to figure out the eco-friendly laminating method. Third, the flame retardant ability was compared the halogen laminated textiles to halogen-free laminated textiles. LOI, UV protection ratio, antibiosis after 50 laundry test, water proof pressure, and moisture permeability of developed textiles were tested. GC-HR-TOF-MS was used for analysis of laminating film (halogen and halogen-free). 4.1 wt% TiO2 yarn showed antibacterial function (Pneumococcus & Staphylococcus aureus: 99.9%), UV Protection (UVA: 90.8, UVB: 92.1), and LOI (33.6). The chosen optimal compounding ratio for PU compound of HRF and HFFR were as followed: PU resin 58.3%, DMF (Dimethyl formamide, δ = 12.2) 8.3%, MEK (Methylethylketone) 8.3% and FR (flame retardants) 25.0%. Binder for laminating should not be included over 10% of FRs because of adhesion between textiles and FR laminating film. There were detected phosphorus compounds in the textiles treated by halogenated type flame retardants and halogenated-free type flame retardants. There were not any detected harmful compounds from all textile samples.

QSAR Study of Halogen Phenols Toxicity to Tetrahymena Pyriformis

Structural parameters of 22 halogen phenols were computed at four levels using Hartree-Fock and DFT methods. Based on the experimental data of the acute toxicity to Tetrahymena pyriformis （-lgEC_50）, three-parameter （energy of the lowest unoccupied molecular orbital （E_LUMO）, the molecular volume （V）, and the lowest negative charge （Q_min）） dependent equations were developed using structural parameters as theoretical descriptors. Especially, -lgEC_50dependent equation calculated at the B3LYP/6-31G^＊＊ level is more advantageous than the others in view of their correlation and predictive abilities. This dependent equation was validated by variance inflation factors （VIF） and t-test methods. Upon comparison, the predictive abilities of our work are all more advantageous than those calculated from the semi-empirical PM3 method.

Determination of the Toxicities of 16 Halogenated Benzenes to Photobacterium Phosphoreum and 2D- and 3D-QSAR Studies

In this paper we take photobacterium phosphoreum （T3） as the experimental bacteria, and determine the half-inhibitory concentration （-1gEC50） against the photobacterium phosphoreum of 16 halogenated benzenes. Using B3LYP method of DFT in the Gaussian 03 program, we obtain the structural and thermodynamic descriptors of 16 halogenated benzenes by fully-optimized calculation at the 6-311G＊＊ level. Taking the structural and thermodynamic descriptors as theoretical descriptors, the 2D QSAR model （R2 = 0.983） was established, which can be utilized to predict -lgEC50 of halogenated benzene according to the corrected linear solvation energy theory based on the experimental data of-lgECs0. In addition, the relationship between the toxicity and 3D spatial structure of the compound is studied by comparing the molecular similarity index analysis （CoMSIA） of 3D-QSAR method. By cross validation, the correlation coefficient q2 of CoMSIA model is 0.687, and the conventional correlation coefficient R2 = 0.958. The model is stable and reliable with great predictive ability. The 3D-QSAR model shows that the toxicity of halogenated benzene compound is mainly affected by the characteristics of hydrophobie field of the substituted halogens.

A QSRR Study on the Relative Retention Time of Halogenated Methyl-phenyl Ethers

Halogenated methyl-phenyl ethers （anisoles） are ubiquitous organic compounds in the environment. In the present study, geometrical optimization and electrostatic potential calculations have been performed for 42 halogenated anisoles at the HF/6-31 G^＊ level. A number of statistically based parameters have been obtained. By multiple regression method, linear relationships between the gas-chromatographic relative retention time （RRT） and structural descriptors have been established for the training set of 32 halogenated anisoles. The result showed that the parameters derived from electrostatic potentials （ESPs） together with the molecular volume （Vmc） could be well used to express the quantitative structure-RRT relationships of halogenated anisoles. The best two-variable regression model gives a correlation coefficient of 0.980 and a standard deviation of 0.07, and the leave-one-out cross-validated correlation coefficient is 0.975. The goodness of the model has been further validated through exploring the predictive power for the testing set of 10 halogenated anisoles.

The photodynamic therapy on Streptococcus mutans biofilms using erythrosine and dental halogen curing unit

The purpose of our study was to evaluate the effect of photodynamic therapy （PDT）, using erythrosine as a photosensitizing agent and a dental halogen curing unit as a light source, on Streptococcus mutans in a biofilm phase. The S. mutans biofilms were formed in a 24-well cell culture cluster. Test groups consisted of biofilms divided into four groups： group 1： no photosensitizer or light irradiation treatment （control group）; group 2： photosensitizer treatment alone; group 3： light irradiation alone; group 4： photosensitizer treatment and light irradiation. After treatments, the numbers of colony-forming unit （CFU） were counted and samples were examined by confocal laser scanning fluorescence microscopy （CLSM）. Only group 4 （combined treatment） resulted in significant increases in cell death, with rates of 75% and 55% after 8 h of incubation, and 74% and 42% at 12 h, for biofilms formed in brain-heart infusion （BHI） broth supplemented with 0% or O. 1% sucrose, respectively. Therefore, PDT of S. mutans biofilms using a combination of erythrosine and a dental halogen curing unit, both widely used in dental clinics, resulted in a significant increase in cell death. The PDT effects are decreased in biofilms that form in the presence of sucrose.

Prediction of Infinite Dilution Activity Coefficients of Halogenated Hydrocarbons in Water

Geometrical optimization and electrostatic potential calculations have been performed for a series of halogenated hydrocarbons at the HF/Gen-6d level. A number of electrostatic potentials and the statistically based structural descriptors derived from these electrostatic potentials have been obtained. Multiple linear regression analysis and artificial neural network are employed simultaneously in this paper. The result shows that the parameters derived from electrostatic 2 potentials σtot^2, V s and ∑ Vs^＋, together with the molecular volume （Vine） can be used to express the quantitative structure-infinite dilution activity coefficients （γ^∞） relationship of halogenated hydrocarbons in water. The result also demonstrates that the model obtained by using BFGS quasiNewton neural network method has much better predictive capability than that from multiple linear regression. The goodness of the model has been validated through exploring the predictive power for the external test set. The model obtained via neural network may be applied to predict γ^∞ of other halogenated hydrocarbons not present in the data set.

Theoretical Study of Halogen Effect in Isomerization of 2-Halo-[9]-annulen Anion at the DFT Level

Cis-trans isomerization of [9]-annulenanion（1） and its 2-fluoro-,2-chloro-and 2-bromo-derivatives（2,3 and 4,respectively） were investigated at the HF/6-31G＊ and B3LYP/6-311＋＋G＊＊ levels of theory.Cis,cis,cis,cis structures appear more stable than their corresponding cis,cis,cis,trans-isomers.The relative height of energy barriers for cis-trans isomerization is：2cis 〉1cis 〉3cis〉 4cis.This trend for the reverse trans-cis isomerization follows the electronegativity of the substituent at C-2（2trans 3trans 4trans 1trans）.

An assessment study of absorption effect:LED vs tungsten halogen lamp for noninvasive glucose detection

Noninvasive gluoose monitoring development is critical for diabetic patient continuous moni-toring.However,almost all the available devices are invasive and painful.Noninvasive methods such as using spectroscopy have shown some good results.Unfortunately,the drawback was that the tungsten halogen lamps 1usage that is impractical if applied on human skin.This paper compared the light emitting diode(LED)to traditional tungsten halogen lamps as light source for glucose detection where the type of light source plays an important role in achieving a good spectrum quality.Glucose concentration measurement has been developed as part of noninvasive technique using optical spectroscopy.Small change and overlapping in tungsten halogen results need to replace it with a more convenient light source such as LED.Based on the result obtained,the performance of LED for absorbance spectrum gives a signifcantly different and is directly proportional to the glucose concentration.The result shows a linear trend and scucssully detects lowest at 60 to 160 mg/dL glucose concentration.

The Principle of Introducing Halogen Ions Into β-FeOOH: Controlling Electronic Structure and Electrochemical Performance

Coordination tuning electronic structure of host materials is a quite effective strategy for activating and improving the intrinsic properties.Herein,halogen anion(X-)-incorporated β-FeOOH(β-FeOOH(X),X=F-,Cl-,and Br-) was investigated with a spontaneous adsorption process,which realized a great improvement of supercapacitor performances by adjusting the coordination geometry.Experiments coupled with theoretical calculations demonstrated that the change of Fe-O bond length and structural distortion of β-FeOOH,which is rooted in halogen ions embedment,led to the relatively narrow band gap.Because of the strong electronegativity of X-,the Fe element in β-FeOOH(X)s presented the unexpected high valence state(3+δ),which is facilitating to adsorb S032-species.Consequently,the designed β-FeOOH(X)s exhibited the good electric conductivity and enhanced the contact between electrode and electrolyte.When used as a negative electrode,the β-FeOOH(F) showed the excellent specific capacity of 391.9 F g-1 at 1 A g-1 current density,almost tenfold improvement compared with initial β-FeOOH,with the superior rate capacity and cyclic stability.This combinational design principle of electronic structure and electrochemical performances provides a promising way to develop advanced electrode materials for supercapacitor.

Influence of Structural Variations on Electrical Conductivity and Solubility of 1-Vinyl-3-alkylimidazole Halogen Ionic Liquids

Several 1-vinyl-3-alkylimidazolium halogens [VRIM]X, which are functional materials with ethylenic bonds, were synthesized using the microwave-assisted synthesis method. Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy were carded out to analyze the resultant structures. The electrochemical properties and solubility of [VRIM]Br were investigated and discussed in detail. The temperature dependence of pure [VRIM]Br over a wide temperature range of 298.15-323.15 K fitted the Arrhanius equation well. At certain low concentrations, the electrical conductivity of the [VRIM]Br solution significantly increased with increasing solution concentration. The electrical conductivities of the [VRIM]Br observed in water, methanol, and ethanol showed the trend σwater〉 σmethanol 〉σethanol Conductometry showed that the critical miceUe concentrations of the bromines in water, methanol, and ethanol were 6.8-6.9 × 10-6, 1.4-1.5 × 10-5, and 1.9-2.0×10-5 mol.L-1, respectively; these results indicate that [VRIM]Br is an excellent surfactant. The solubility of [VRIM]X in common solvents was determined at 293.15 K, and results indicated that a decrease in solubility could be observed with decreasing dielectric constant of the solvent, elongation of the alkyl chain of the cation, and increasing anion size. Solubility parameters were also determined according to the Hildebrand-Scoff equation.

Halogen Storage Electrode Materials for Rechargeable Batteries

The ever-increasing demand for rechargeable batteries with high energy density,abundant resources,and high safety has pushed the development of various battery technologies based on cation,anion,or dual-ion transfer.The use of halogen storage electrode materials has led to new concept battery systems such as halide-ion batteries(HIB)and dual-ion batteries(DIB).This review highlights the recent progress on these electrode materials,including metal(oxy)halides,layered double hydroxides,MXenes,graphite-based materials,and organic materials with carbon or nitrogen redox centers.The reversible electrochemical halogen storage of halide ions(e.g.,F^(−),Cl^(−),and Br^(−)),dual halogen(e.g.,Br_(m)Cl_(n) and [ICl_(2)]^(−)),or binary halide anions(e.g.,PF_(6)^(−),AlCl_(4)^(−),[ZnCl_(x)]^(2−x),and [MgCl_(x)]^(2−x)) in the electrodes is covered.The challenges and mechanisms of halogen storage in various electrode materials in HIBs and DIBs are summarized and analyzed,providing insights into the development of high-performance halogen storage electrode materials for rechargeable batteries.

Clicking ferrocene to halogenated boron-doped diamond surfaces

The halogenated boron-doped diamond （BDD） surfaces were reacted with sodium azide through a nucle- ophilic substitution reaction. The resulting azide-terminated BDD surfaces were used to trigger the ＂click＂ reaction. Because of the attractive electrochemical properties of ferrocene-containing molecules, such as fast electron transfer rates, reversible redox activities, and favorable redox potentials, we show that ferrocene derivatives can be grafted onto non-oxidized diamond surfaces by ＂click chemistry＂. These redox-active ferrocene-containing layers on a BDD surface, because of their ability to store and release charges reversibly, have the potential to be used as hybrid molecular/semiconductor memory devices.

Ab Initio Calculations on Halogen Bond Between N—Br and Electron-donating Groups

Ab initio calculations of complexes formed between N-bromosuccinimide and a series of electron-donating groups were performed at the level of MP2/Lanl2DZ^＊ to gain a deeper insight into the nature of the N--Br halogen bonding. For the small complexes, H3 C--Br… NH3 and H2 N--Br…NH3 , the primary calculation has demonstrated that the N--Br in H2 N--Br… NH3 can form a much stronger halogen-bonding complex than the C--Br. A comparison of neutral hydrogen bond complex series reveals that the electron-donating capacities of the atoms decrease in the order, N 〉 O 〉 S; 0 （ sp^3 ） 〉 0 （ sp^2 ）, which is adequate for the C--Br halogen bonding. Interaction energies, in conjunction with the geometrical parameters show that the affinitive capacity of trihalide anions X^-3 with N-bromosuccinimide are markedly lower than that of the corresponding X^- with N-bromosuccinimide, even lower than those of neutral molecules with N-bromosueeinimide. AIM analyses further eorffirmed the above results.

Cyclization and halogenation of substituted o-allylphenols with diacetoxyiodobenzene in the presence of iodine or bromine

Substituted 2-halomethyl-2,3-dihydrobenzofurans were synthesized in one pot and in mild yield from substituted o-allylphenols with diacetoxyiodobenzene in the presence of 12 or Br2 in dry CH2Cl2 under reflux.

Accurate studies on the full vibrational energy spectra and molecular dissociation energies for some electronic states of halogen molecule

This paper obtains accurate vibrational spectroscopic constants and full vibrational energy spectrum by the al- gebraic method （AM） for some electronic states of halogen diatomic molecules. Motivated by the recent success of obtaining the dissociation energies of Li2 molecule by using a new analytical formula, it further extends the formula to study the dissociation energies of halogen diatomic molecules. The results show that the AM spectrum and the theoretical dissociation energies agree well with RKR data and experimental data respectively.

Theoretical Study of the Iodine-catalyzed Nucleophilic Addition by Halogen Bond

The iodine-catalyzed nucleophilic addition of pyrrole to acetone has been studied by density functional theory at the level of Lanl2DZ＊. It has been shown that the first iodine molecule appears to have a remarkable catalytic effect on this reaction by halogen bond between carbonyl oxygen and iodine molecule, but the second one does not improve the reaction largely. In general, the nucleophilic addition at the C（2） site of pyrrole is more favorable than that at the C（3） site; however, this trend is not prominent or even changed in acetronitrile solvent for the indole system, which is consistent with the experimental result by Bandgar.