Spectroelectrochemical characterization of iron(III)-thiocyanate complexes in acidic thiocyanate solutions at an optically transparent thin-layer-electrode cell

Itabashi, Eiki

doi:10.1021/ic00218a013

Cited by 19 publications

(10 citation statements)

References 2 publications

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“…In spectroelectrochemical studies of the oxidation of SCN - , it was reported that the strongly absorbing species (SCN) 3 - rather than (SCN) 2 is generated. , This inference was based on the drastic differences between the spectrum of the observed intermediate and that reported for (SCN) 2 . A gold minigrid electrode was used in these studies; most likely the observed species was a gold−thiocyanate complex, formed through electrodissolution of the electrode.…”

Section: Discussionmentioning

confidence: 99%

Kinetics and a Revised Mechanism for the Autocatalytic Oxidation of SCN^-by ClO₂

Figlar

Stanbury

1999

J. Phys. Chem. A

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The aqueous reaction of chlorine dioxide with excess thiocyanate is known to be autocatalytic at pH 2. We find that under strongly acidic conditions (>0.1 M HClO4) it is pseudo-first-order with respect to [ClO2]. Under these conditions, the rate law is −d[ClO2]/dt = (2k 1 + 2k 2[H+])[ClO2][SCN-], with 2k 1 = 0.42 M-1 s-1 and 2k 2 = 0.52 M-2 s-1 at 25 °C and μ = 1 M (LiClO4). Effective activation parameters in 1 M HClO4 are ΔH ⧧ = 66.5 kJ/mol and ΔS ⧧ = −26.3 J/mol for the temperature range 13.4−52.2 °C. Reaction products were identified by ion chromatography and ion-selective electrodes, which allowed a verification of the stoichiometry, 6ClO2 + 5SCN- + 8H2O → 6Cl- + 5CN- + 5SO4 2- + 16H+. Direct evidence for a reaction intermediate, thiocyanogen, was obtained through careful analysis of multiwavelength rapid scanning data. This intermediate provides a reactive autocatalytic species OSCN- via hydrolysis equilibrium, and this equilibrium was found to be important to simulations and fits to raw data. A 14-step mechanism is employed for these fits and simulations, allowing a more thorough description of the reaction system; this mechanism successfully reproduces both the full rate law under pseudo-first-order conditions and the autocatalytic behavior at pH 2.

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Section: Discussionmentioning

confidence: 99%

Kinetics and a Revised Mechanism for the Autocatalytic Oxidation of SCN^-by ClO₂

Figlar

Stanbury

1999

J. Phys. Chem. A

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“…An excess of Fe (III)-ion present in the solution would react with thiocyanate ion to form a characteristic pink complex, Fe (SCN). The optical density at 465 nm was measured, 14 and an inverse linear relation was found for phytate concentration from 40 to 200 nmol/L. About 0.2 g of the sample was placed in 100 mL conical flask to determined tannin.…”

Section: Analyses Methodsmentioning

confidence: 99%

Product Development and Quality Evaluation of Biscuit and Ready-to-Eat Snack from Cowpea-wheat Flour Blends

Yilma¹,

Admassu²

2019

Adv Food Technol Nutr Sci Open J

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AimThe research was conducted with the aim to develop biscuit and ready-to-eat snack product from cowpea flour incorporated with wheat flour. MethodsThe wheat and cowpea flour blends were prepared in five blending ratios including B1 (90:10), B2 (40:60), B3 (65:35), B4 (78:22), and B5 (53:47); respectively. The D-optimal mixture design software was used for flour blend formulation. Biscuit and extrudate products from cowpea and wheat blends were analyzed. Quality characteristics parameter used for value-added products includes physical, functional, proximate, mineral and microbial quality. Furthermore, bioactive components and sensory quality evaluation were also investigated. The biscuit samples were prepared at a baking temperature of 205 °C for 10-minutes holding time. The extrudate samples were also manufactured at feed moisture (18 and 21%), barrel temperature (100, 110 and 120 °C) and screw speed (175 and 220 rpm). ResultsThe result for crude protein analysis of biscuit (B3) and extrudate (Ex-3) samples was revealed that 15.972±0.125, and 15.915±0.251; respectively. The result for microbial quality analysis of biscuit (B3) and extrudate (Ex-3) samples was also shown as aerobic bacteria count of 44×10 -5 , 42×10 -5 and yeast and mold (un-detected); respectively. The highest overall sensory evaluation of biscuit (B3) and extrudate (Ex-3) samples score were found 7.6 and 7.14; respectively. ConclusionBased on quality evaluation parameters, 35% cowpea flour with 65% of wheat flour blending ratio reveled sensor acceptable for biscuit production and manufacturing of ready-to-eat snack. Admassu S et al 93 Original Research | Volume 5 | Number 3|Extrusion combines a number of unit operation i.e. mixing, cooking, shearing, puffing, final shaping and drying in one energy efficient rapid continues process 5 and can be used to reduce a wide variety of starchy foods including snacks, ready to eat (RTE), confectioners, and extruded crispbreads. This process of hightemperature short time extrusion brings gelatinization of starch, denaturation of protein, modification of lipid and inactivation of enzymes, microbes and many anti-nutritional factors. 6 The aim of this research was to develop and evaluate the substitution of wheat by cowpea and then investigate the quality of value-added products.

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“…Here we report on the heteronuclear, mixed‐valent coordination compounds 1 and 2 , which contain Fe 2+ , Fe 3+ , and Ag + ions and are formed according to Equation (1) in nitromethane and crystallized by addition of diethyl ether. The partial reduction of the Fe 3+ ions is due to the reducing effect of thiocyanate, which is oxidized to (SCN) 2 and subsequent products 9 …”

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confidence: 99%

Chemisorption of Exchange‐Coupled [Ni₂L(dppba)]⁺ Complexes on Gold by Using Ambidentate 4‐(Diphenylphosphino)benzoate Co‐Ligands

Golecki¹,

Lach²,

Jeremies³

et al. 2013

Chemistry A European J

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A new strategy for the fixation of redox-active dinickel(II) complexes with high-spin ground states to gold surfaces was developed. The dinickel(II) complex [Ni2L(Cl)]ClO4 (1ClO4), in which L(2-) represents a 24-membered macrocyclic hexaaza-dithiophenolate ligand, reacts with ambidentate 4-(diphenylphosphino)benzoate (dppba) to form the carboxylato-bridged complex [Ni2L(dppba)](+), which can be isolated as an air-stable perchlorate [Ni2L(dppba)]ClO4 (2ClO4) or tetraphenylborate [Ni2L(dppba)]BPh4 (2BPh4) salt. The auration of 2ClO4 was probed on a molecular level, by reaction with AuCl, which leads to the monoaurated Ni(II)2Au(I) complex [Ni(II)2L(dppba)Au(I)Cl]ClO4 (3ClO4). Metathesis of 3ClO4 with NaBPh4 produces [Ni(II)2L(dppba)Au(I)Ph]BPh4 (4BPh4), in which the Cl(-) is replaced by a Ph(-) group. The complexes were fully characterized by ESI mass spectrometry, IR and UV/Vis spectroscopy, X-ray crystallography (2BPh4 and 4BPh4), cyclic voltammetry, SQUID magnetometry and HF-ESR spectroscopy. Temperature-dependent magnetic susceptibility measurements reveal a ferromagnetic coupling J = +15.9 and +17.9 cm(-1) between the two Ni(II) ions in 2ClO4 and 4BPh4 (H = -2 JS1S2). HF-ESR measurements yield a negative axial magnetic anisotropy (D<0), which implies a bistable (easy axis) magnetic ground state. The binding of the [Ni2L(dppba)]ClO4 complex to gold was ascertained by four complementary surface analytical methods: contact angle measurements, atomic-force microscopy, X-ray photoelectron spectroscopy, and spectroscopic ellipsometry. The results indicate that the complexes are attached to the Au surface through coordinative Au-P bonds in a monolayer.

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Spectroelectrochemical characterization of iron(III)-thiocyanate complexes in acidic thiocyanate solutions at an optically transparent thin-layer-electrode cell

Cited by 19 publications

References 2 publications

Kinetics and a Revised Mechanism for the Autocatalytic Oxidation of SCN^-by ClO₂

Kinetics and a Revised Mechanism for the Autocatalytic Oxidation of SCN^-by ClO₂

Product Development and Quality Evaluation of Biscuit and Ready-to-Eat Snack from Cowpea-wheat Flour Blends

Chemisorption of Exchange‐Coupled [Ni₂L(dppba)]⁺ Complexes on Gold by Using Ambidentate 4‐(Diphenylphosphino)benzoate Co‐Ligands

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Spectroelectrochemical characterization of iron(III)-thiocyanate complexes in acidic thiocyanate solutions at an optically transparent thin-layer-electrode cell

Cited by 19 publications

References 2 publications

Kinetics and a Revised Mechanism for the Autocatalytic Oxidation of SCN-by ClO2

Kinetics and a Revised Mechanism for the Autocatalytic Oxidation of SCN-by ClO2

Product Development and Quality Evaluation of Biscuit and Ready-to-Eat Snack from Cowpea-wheat Flour Blends

Chemisorption of Exchange‐Coupled [Ni2L(dppba)]+ Complexes on Gold by Using Ambidentate 4‐(Diphenylphosphino)benzoate Co‐Ligands

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Product

Resources

About

Kinetics and a Revised Mechanism for the Autocatalytic Oxidation of SCN^-by ClO₂

Kinetics and a Revised Mechanism for the Autocatalytic Oxidation of SCN^-by ClO₂

Chemisorption of Exchange‐Coupled [Ni₂L(dppba)]⁺ Complexes on Gold by Using Ambidentate 4‐(Diphenylphosphino)benzoate Co‐Ligands