16759-25-4Relevant academic research and scientific papers
Electrochemistry of Br-/Br2 Redox Couple in Acetonitrile, Methanol and Mix Media of Acetonitrile-Methanol: An Insight into Redox Behavior of Bromide on Platinum (Pt) and Gold (Au) Electrode
Tariq, Muhammad
, p. 295 - 312 (2019/06/07)
Electro-oxidation of Br- on platinum and gold electrode was studied in acetonitrile, methanol and mix media of acetonitrile-methanol. The mechanism of Br- oxidation in these media was investigated using CV, Semi Integration Cyclic Vo
A novel polyoxometalate-encapsulating 3D polycatenated metal-organic framework
Li, Shaobin,Lu, Borong,Xin, Jianjiao,Zhang, Li,Pan, Jing,Chen, Yue,Tan, Xiaoguo
, (2019/08/20)
A novel polyoxometalate-encapsulating polycatenated metal-organic framework, (bib)0.5[Cu2(bib)3.5(GeW12O40)]·H2O (1) (bib = 1,4-bis(1-imidazol-yl)-2,5-dimethyl benzene), has been synthesize
Pt embedded in carbon rods of N-doped CMK-3 as a highly active and stable catalyst for catalytic hydrogenation reduction of bromate
Li, Minghui,Hu, Yuan,Fu, Heyun,Qu, Xiaolei,Xu, Zhaoyi,Zheng, Shourong
supporting information, p. 11786 - 11789 (2019/10/02)
A novel Pt-based catalyst with fine and homogeneous Pt particles embedded in carbon rods of N-doped CMK-3 was fabricated by a two-step infiltration method using SBA-15 as the template. Due to its fine particle size, N-containing functionality and effective embedment of Pt particles in carbon rods, the catalyst exhibited superior catalytic activity and stability in the liquid phase catalytic hydrogenation of bromate in water.
Extraction and stripping of platinum (IV) from acidic chloride media using guanidinium ionic liquid
Wang, Ning,Wang, Qi,Lu, Wenjuan,Ru, Miaoyan,Yang, Yanzhao
, (2019/08/26)
The extraction and stripping behaviors of Pt(IV) from acidic chloride media by 2,2-diheptyl-1,1,3,3-tetramethylguanidinium bromide were investigated. The extraction of Pt(IV) was carried out by modulating various parameters such as concentration of the extractant, temperature, and concentration of HCl solution. Based on the characterization of experimental results such as Job's method data, UV–vis spectra and fourier transform infrared spectra analysis, the anion exchange mechanism was confirmed. Quantum chemical calculations were performed to provide theoretical support for the mechanism. The ionic liquid showed outstanding selectivity for Pt(IV) over the base metals. Furthermore, the organic phase could be easily used for four extraction-stripping cycles by reductive stripping process using 0.5 M CS(NH2)2/0.5 M HCl. The numbers of theoretical stages needed for the effective extraction and stripping of Pt(IV) has been determined by McCabe Thiele's diagram. Under the selected counter-current extraction and stripping stages, the extraction efficiency and stripping efficiency could reach 99.5% and 99.0%, respectively. Therefore, the system is highly effective, selective and recyclable to extract Pt(IV). On the basis of the extraction protocol, the system may be a promising candidate for highly selective extraction of Pt(IV).
Visible Light Driven Bromide Oxidation and Ligand Substitution Photochemistry of a Ru Diimine Complex
Li, Guocan,Brady, Matthew D.,Meyer, Gerald J.
, p. 5447 - 5456 (2018/05/01)
The complex [Ru(deeb)(bpz)2]2+ (RuBPZ2+, deeb = 4,4′-diethylester-2,2′-bipyridine, bpz = 2,2′-bipyrazine) forms a single ion pair with bromide, [RuBPZ2+, Br-]+, with Keq = 8400 ± 200 M-1 in acetone. The RuBPZ2+ displayed photoluminescence (PL) at room temperature with a lifetime of 1.75 μs. The addition of bromide to a RuBPZ2+ acetone solution led to significant PL quenching and Stern-Volmer plots showed upward curvature. Time-resolved PL measurements identified two excited state quenching pathways, static and dynamic, which were operative toward [RuBPZ2+, Br-]+ and free RuBPZ2+, respectively. The single ion-pair [RuBPZ2+, Br-]+? had a lifetime of 45 ± 5 ns, consistent with an electron transfer rate constant, ket = (2.2 ± 0.3) × 107 s-1. In contrast, RuBPZ2+? was dynamically quenched by bromide with a quenching rate constant, kq = (8.1 ± 0.1) × 1010 M-1 s-1. Nanosecond transient absorption revealed that both the static and dynamic pathways yielded RuBPZ+ and Br2?- products that underwent recombination to regenerate the ground state with a second-order rate constant, kcr = (2.3 ± 0.5) × 1010 M-1 s-1. Kinetic analysis revealed that RuBPZ+ was a primary photoproduct, while Br2?- was secondary product formed by the reaction of a Br? with Br-, k = (1.1 ± 0.2) × 1010 M-1 s-1. Marcus theory afforded an estimate of the formal reduction potential for E0(Br?/-) in acetone, 1.42 V vs NHE. A 1H NMR analysis indicated that the ion-paired bromide was preferentially situated close to the RuII center. Prolonged steady state photolysis of RuBPZ2+ and bromide yielded two ligand-substituted photoproducts, cis- and trans-Ru(deeb)(bpz)Br2. A photochemical intermediate, proposed to be [Ru(deeb)(bpz)(κ1-bpz)(Br)]+, was found to absorb a second photon to yield cis- and trans-Ru(deeb)(bpz)Br2 photoproducts.
Palladium nanoparticles encapsulated in core-shell silica: A structured hydrogenation catalyst with enhanced activity for reduction of oxyanion water pollutants
Wang, Yin,Liu, Jinyong,Wang, Peng,Werth, Charles J.,Strathmann, Timothy J.
, p. 3551 - 3559 (2015/02/19)
Noble metal nanoparticles have been applied to mediate catalytic removal of toxic oxyanions and halogenated hydrocarbons in contaminated water using H2 as a clean and sustainable reductant. However, activity loss by nanoparticle aggregation and
Enhancing the anion affinity of urea-based receptors with a Ru(terpy) 22+ chromophore
Baggi, Giorgio,Boiocchi, Massimo,Ciarrocchi, Carlo,Fabbrizzi, Luigi
, p. 5273 - 5283 (2013/06/26)
Covalent linking of a Ru(terpy)22+ substituent improves recognition and sensing properties of the urea subunit toward anions. Urea's anion affinity is enhanced by the electrostatic attraction exerted by the RuII cation and by the electron-withdrawing effect exerted by the entire polypyridine-metal complex. Such an enhancement of the anion affinity, which results from the combination of a through-space and a through-bond effect, is greater than that exerted by the classical neutral electron-withdrawing substituent nitrophenyl. Small yet significant modifications of π-π* and MLCT bands of the Ru(terpy)22+ chromophore, detected through UV-vis spectrophotometric titrations, allowed the determination of the constants for the formation of receptor-anion H-bond complexes in diluted MeCN solution. On 1H NMR titration experiments, carried out under more concentrated conditions, the interaction of a second Cl- ion was observed, taking place through an outer-sphere mechanism. The Ru(terpy) 22+ substituent favors the deprotonation of a urea N-H fragment on addition of a second equivalent of fluoride, with formation of HF2-.
Bisulfite-driven autocatalysis in the bromate-thiosulfate reaction in a slightly acidic medium
Wang, Zhen,Gao, Qingyu,Pan, Changwei,Zhao, Yuemin,Horvath, Attila K.
, p. 12062 - 12064 (2013/01/15)
The thiosulfate-bromate reaction has been studied by high-performance liquid chromatography, monitoring the concentrations of thiosulfate and tetrathionate simultaneously. It is found that concentration-time curves of both species display a sigmoidal shape in a slightly acidic, well-buffered medium. Unlike the previously reported complex reaction systems involving bromate, this nonlinear dynamical behavior originates from neither proton nor bromine(III) autocatalysis under our experimental conditions. We demonstrated that sulfur(IV) species significantly accelerates the reaction; therefore, it acts as an autocatalyst. To the best of our knowledge, no reaction system has yet been reported among the pH-driven oxysulfur-oxyhalogen systems, where sulfur(IV) has such a remarkable role. On the basis of the simultaneous evaluation of [S 2O32-] and [S4O6 2-] time series, an eight-step kinetic model is proposed to account for the experimental observations. The model employed here may serve as a solid starting point to extend it for other oxysulfur-oxyhalogen systems where such a seemingly general phenomenon may become observable.
Simultaneous evaluation of different types of kinetic traces of a complex system: Kinetics and mechanism of the tetrathionate - bromine reaction
Varga, Denes,Horvath, Attila K.
, p. 9988 - 9996 (2010/02/16)
The bromine-tetrathionate reaction has been studied in the presence of phosphoric acid/dihydrogen phosphate buffer at T = 25 ± 0.1°C and at I = 0.5 M ionic strength with both stopped-flow technique and a conventional diode array spectrophotometer. The sto
Reaction of Br2 with adsorbed CO on Pt, studied by the surface interrogation mode of scanning electrochemical microscopy
Wang, Qian,Rodriguez-Lopez, Joaquin,Bard, Allen J.
, p. 17046 - 17047 (2010/03/25)
(Chemical Equation Presented) Scanning electrochemical microscopy surface interrogation (SI-SECM) in the cyclic voltammetry mode was successfully used to detect and quantify adsorbed CO on a Pt electrode by reaction with electrogenerated Br2. T
