Viologen derivatives feature two reversible one-electron redox processes and have been extensively utilized in aqueous organic flow batteries (AOFBs). However, the early variant, methyl viologen (MVi), exhibits low stability electrolytes, restricting its practical implementation AOFB technology. In this context, leveraging tunability of molecules, various substituents incorporated into core to achieve better stability, lower potential, improved solubility. work, we introduce...

Abstract Iron(II) complexes with 1,10‐phenanthroline (phen) and 2,2′;6′,2“‐terpyridine (terpy) ligands bearing different functional groups (methyl, 4‐pyridyl, chloro, carboxylic acid) were evaluated for aqueous flow battery applications, detecting oxidation processes followed by coupled chemical reactions. Redox potentials of these compounds sufficiently high suitable positive electrolytes (0.88–1.29 V vs. SHE). Randles‐Ševčík equation finite element modelling COMSOL Multiphysics utilized in...

Analyte concentration effects on the first reduction process of methyl viologens and diquat redox flow battery electrolytes were examined by cyclic voltammetry in aqueous media. A simple one-electron transfer mechanism to form radical cations was detected for diquat, 4,4′-dimethyl bis(3-trimethylammonio)-propyl viologen compounds. The attach electrode surface when source their electrogeneration is molecules bearing PF6– ions as a counterpart. However, this inner sphere not observed having an...

Finding two-electron storage aqueous organic negolytes is crucial for increasing the charge capacity in next-generation flow batteries. Inspired by ability of gallocyanine compound (GAL) to act as an efficient transfer mediator biology, we investigated its reduction process cyclic voltammetry at alkaline conditions, detecting ion pairing (with Na+, K+, or Li+ ions) and H+ pathways electrogenerated species. The voltammetric responses obtained were dependent on concentrations analyte...

In recent years interest in the development of protocols that facilitate oxidative addition gold to access mild cross-coupling processes mediated by this metal has increased. context, we report herein ascorbic acid, a natural and readily accessible antioxidant, can be used accelerate aryldiazonium chlorides onto AuI . The aryl-AuIII species generated way, been prepare 3-arylindoles one-pot protocol starting from anilines para-, meta-, ortho- substituted chlorides. mechanism underlying...

An electrochemical analysis strategy based on the Marcus–Hush approximation is presented to analyze kinetic component of organic redox flow battery (RFB) electrolytes. The procedure was applied aqueous solutions methyl viologen (MV) and 2,2′-bipyridyl (diquat, DQ) derivatives as model redox-active electrolytes; although these systems are promising negolyte candidates in RFBs, their electrode kinetics continues be unclear. For compound MV, voltammetric revealed an adsorption process...

Evaluation of the substituent effect in reaction series is an issue interest, as it fundamental for controlling chemical reactivity molecules. Within framework density functional theory, employment potential, μ, and hardness, η, leads to calculation properties common use, such electrodonating (ω(-)) electroaccepting (ω(+)) powers, many systems. In order examine predictive character by these indexes, a comparison between experimental binding constants (Kb) radical anions from para-...

Competition between hydrogen bonding and proton transfer reactions was studied for systems composed of electrogenerated dianionic species from dinitrobenzene isomers substituted dihomooxacalix[4]arene bidentate urea derivatives. To analyze this competition, a second-order ErCrCi mechanism considered where the binding process is succeeded by voltammetric responses depend on two dimensionless parameters: first related to reactions, second one processes. Experimental results indicated that,...

Electron transfer controlled hydrogen bonding was studied for a series of nitrobenzene derivative radical anions, working as large guest and substituted ureas, including dihomooxacalix[4]arene bidentate urea derivatives, in order to estimate binding constants (Kb) the hydrogen-bonding process. Results showed enhanced Kb values interaction with phenyl-substituted urea, which is significantly larger than remaining compounds, e.g., case 4-methoxynitrobenzene 28-fold value obtained bearing...

Abstract In this work, an electrochemical and spectroelectrochemical ESR study for a series of hydroxyl substituted 1,4‐naphthoquinones is presented. Results show that the behaviour dependent on relative positions these groups within molecules. For compounds which have at annellated benzene ring, intramolecular hydrogen bonding (a substituent field effect) determines energy reduction system. When functions are located C‐2 or C‐3 positions, selfprotonation process occurs. The electrogenerated...

In this work, experimental evidence of the influence electron transfer kinetics during controlled hydrogen bonding between anion radicals metronidazole and ornidazole, derivatives 5-nitro-imidazole, 1,3-diethylurea as bond donor, is presented. Analysis variations voltammetric EpIcvs. log KB[DH], where KB binding constant, allowed us to determine values constant also rate k, confirmed by experiments obtained at different scan rates. Electronic structure calculations BHandHLYP/6-311++G(2d,2p)...

Spiropyran (SP) is a type of photochromic molecules widely studied because their interesting physical and chemical properties. Irradiation spiropyrans with near UV-light induces heterolytic cleavage the spiro bond, resulting in possibility application electro-optical molecular devices electronic data storage. Although some reports conclude that opening process also occurs upon electrochemical oxidation indolic nitrogen, complete description both reduction processes, yet unavailable. In this...

Introduction: The woman in the climacteric presents diverse physiological, physical, psychological and social changes, due not only to hormonal decrease, but also lifestyle.Women period present decline, lifestyle.Objective: To analyze relationship between lifestyle a population of State Mexico.Methodology: Quantitative, correlational cross-sectional study. sample consisted 143 women aged 45 59 years, non-probabilistic convenience sampling. Two instruments were applied: Nola Pender's...

Gallocyanine (GAL) was recently introduced as a promising aqueous-soluble electroactive molecule for preparing two-electron storage alkaline flow battery (FB) negolytes. The development of cost-effective GAL FB electrolyte is limited by the unexpectedly low solubility GAL. In this work, compound 7-amino-4-hydroxy-2-naphthalenesulfonic acid molecular spectator to modulate in KOH; formulation allowed preparation negolyte with theoretical volumetric capacity 32.00 Ah L–1. cycling stability an...

Viologen derivatives feature two reversible one-electron redox processes and have been extensively utilized in aqueous organic flow batteries (AOFBs). However, the early variant, methyl viologen (MVi), exhibits low stability electrolytes, restricting its practical implementation AOFB technology. In this context, leveraging tunability of molecules, various substituents incorporated into core to achieve better stability, lower potential, improved solubility. work, we introduce...

Introducción: La diabetes mellitus es una de las enfermedades no trasmisibles más comunes. principal razón que la hace un importante problema sanitario presencia complicaciones. úlcera del pie diabético ellas, ser atendida a tiempo, puede resultar en amputación. Objetivo: Describir características los pacientes con el área salud San Pedro, Belice, periodo siete meses. Método: Se realizó estudio descriptivo y retrospectivo. El universo quedó constituido por 89 atendidos DM, cual se tomó...

By introducing phenyl, 1-naphtyl, 2-thienyl, 2-furanyl and 3-pyridyl rings into 4,7-di(thiophene-2-yl)-benzo[c][2,1,5]thiadiazole structure 2, five new asymmetric derivatives were prepared. For these compounds, HOMO/LUMO gap energy levels estimated by UV-Vis cyclic voltammetry experiments in aprotic solvents. The results showed significant effects of aryl groups on data, this parameter was mainly tuned changes the HOMO level 2. These properties examined also electronic calculations...

Hydrogen bonding is an essential interaction in natural and artificial systems. Its strength can be modulated by employing process known as Electrochemically Controlled (ECHB). Although these processes are assumed to operate under thermodynamic control no experimental evidence for kinetic exists. In this work, ECHB where studied using electrogenerated radical anions from 5-nitroimidazole derivatives receptor molecules 1,3-diethylurea hydrogen bond donor species. Results revealed that occurs...

In Electron Transfer Controlled Hydrogen Bonding (ETCHB), switching molecules experiment changes in their reduction potential values as hydrogen bond donor species (DH) are added to the solution. ETCHB is basis of operation many molecular switches [1-3]; therefore a comprehensive understanding mechanistic routes that govern electron transfer these systems would allow design devices with more specific applications. These processes have been extensively studied employing model molecules, such...

Ascorbic acid, a natural reducing agent, accelerates the oxidative addition of gold to aryldiazonium chlorides. The generated arylgold(III) intermediates are used prepared 3-aryldindoles. mechanism underlying is examined by EPR, electrochemical studies, and DFT calculations. Interestingly, it involves double single oxidation mechanism, where chloride anion plays an important role. cover artwork was designed Hortensia Segura Silva. More information can be found in Full Paper S. Porcel et al....