Photoreduction of iron(III) chloride in aqueous media

David, P. G.

doi:10.1039/c39720001294

Cited by 8 publications

(10 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 10 shows the transient absorption spectra after the laser pulse of the ternary system XYL/H2O2/FeCl3. This is indicative of H2O2 competing with the Clanion and XYL for the Cl • available in the solution (see eq 20). The main difference between the spectra reported in Figures 9 and 10 is the significantly lower intensity of the 420-nm band in the last case.…”

Section: Resultsmentioning

confidence: 88%

Primary Photochemical Reactions in the Photo-Fenton System with Ferric Chloride. 1. A Case Study of Xylidine Oxidation as a Model Compound

Надточенко

Kiwi

1998

Environ. Sci. Technol.

View full text Add to dashboard Cite

Environmental contamination in groundwater involving a variety of nonbiodegradable toxic xylidines from industrial or military effluents is a matter of growing concern. Besides the traditional nondestructive treating methods to remove these substances in water bodies, the application of advanced oxidation technologies such as Fenton photoassisted reactions seems a suitable way to remove and mineralize these contaminants and is the aim of the present study. Primary photochemical reactions in the water solutions of ferric chloride complexes in the absence and in the presence of H 2 O 2 were examined by laser photolysis (λ ) 347 nm) using xylidine (2,4-dimethylaniline, XYL) as probe molecule. The Cl 2 •radicals are formed as a result of the reaction of Cl • atoms and OH • radicals produced during the photodissociation of ferric chloride and ferric hydroxy complexes in the presence of Clanion. The oxidation of xylidine by Cl • or Cl 2 •lead to the formation of the XYL + radical-cation [C 8 H 9 NH 2 ] •+ , having an absorption maximum at λ ) 420 nm which was unambiguously identified by pulsed laser spectroscopy. The decay of XYL + radicals in solution takes place within 2 ms in a secondorder reaction with 2k ) 10 9 (M s) -1 . In solutions containing XYL/H 2 O 2 /FeCl 3 , increasing the oxidant concentration increased the amount of XYL + , indicating that the H 2 O 2 competes with the Cland XYL for the available Cl • in solution. This was not the case of the anion-radical Cl 2 •-. To decide if the radical Cl 2 •or ClOH •prevails after photoexcitation of ferric chloride solutions, a reaction scheme was considered for the formation of the radicals at acidic pH through simultaneous differential equations. The reaction sequence could be kinetically modeled on the basis of laser spectroscopic measurements. The rate constant of Cl 2 •with XYL was found (3.7 ( 0.3) × 10 7 (M s) -1 . Cl • atoms oxidize XYL in the reaction with a constant (4.0 ( 2.0) × 10 10 (M s) -1 . The Cl • atoms react with H 2 O 2 with (1.8 ( 0.7) × 10 10 (M s) -1 . The reaction of Cl • atoms with H 2 O 2 explains the decrease observed for XYL •+ and Cl 2 •radicals in solution with increasing H 2 O 2 concentration. The latter rate constant was observed to be about 5 orders of magnitude higher than the rate constant for the reaction k(Cl 2 •-+ H 2 O 2 f 2Cl -+ H + + HO 2 • ) ) (9.0 ( 0.4) × 10 4 (M s) -1 .

show abstract

Section: Resultsmentioning

confidence: 88%

Primary Photochemical Reactions in the Photo-Fenton System with Ferric Chloride. 1. A Case Study of Xylidine Oxidation as a Model Compound

Надточенко

Kiwi

1998

Environ. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…In another area, there are also serious outstanding ambiguities connected with the nature of the absorbing species responsible for photoreactions. A recent communication (4) in which Fe(I1) yields were examined as a function of p H and chloride ion concentration concluded that reaction followed on absorption by Fe(OH2),-OH2+ but not Fe(OH2),C12+. Since polymerization initiated in chloride-containing solutions produces polymers with both -C1 and -OH terminal groups, there is reason to consider both Can.…”

Section: Introductionmentioning

confidence: 99%

The Charge Transfer Photochemistry of the Hexaaquoiron(III) Ion, the Chloropentaaquoiron(III) Ion, and the µ-Dihydroxo Dimer Explored with tert-Butyl Alcohol Scavenging

Langford¹,

Carey²

1975

Can. J. Chem.

109

View full text Add to dashboard Cite

. Can. J. Chem. 53,2430Chem. 53, (1975. There have been several studies of the charge transfer photochemistry of aqueous Fe3+ but the complexity of hydrolytic equilibria and the requirement for scavengers to render the primary photochemical processes observable has left several issues moot as recent reports show. Using terr-butyl alcohol as a scavenger, it .is shown that (at 35 "C), charge transfer irradiation at 254 nm of Fe(OH2)63+ gives free .OH with a quantum yield of 0.065, charge transfer irradiation of Fe(OH2),C12+ at 350 nm gives free C1. with a quantum yield of 0.093, and that as a result of the combined patterns of extinction coefficients and hydrolytic equilibria it is difficult to make Fe(OH2)50H+ the main absorbing species at either wavelength. The dihydroxo-bridged dimer gives only a small radical yield. The scavenger, rerr-butyl alcohol, appears to react with .OH or CI. to give .CH2-C(CH3)20H which, on reaction with a second Fe(OH2)63+ gives HOCH2C(CH3)2OH.

show abstract

“…For the FeCl 3 solution n D was found to be 1.355, whilst the refractive index of the FeCl 2 solution amounted to n D = 1.338. Therefore it is concluded that the refractive index change of PVA:FeCl 3 as a result of UV irradiation is caused by the change of the oxidation state of the iron ions 5, 20. As the wavelength for measuring the refractive index (λ = 589 nm) is outside the optical absorbance of Fe +3 , anomalous dispersion can be ruled out in this case.…”

Section: Resultsmentioning

confidence: 96%

UV crosslinking of Fe³⁺‐doped poly(vinyl alcohol)—Characterization of optical properties and swelling behavior

Rieß

Kern

2013

J of Applied Polymer Sci

View full text Add to dashboard Cite

The effects of UV irradiation on iron(III)chloride doped poly(vinyl alcohol) (PVA) films, using a high molar mass polymer, have been studied. It has been found that the polymer is oxidized and crosslinked during UV irradiation. UV/VIS spectra reveal an exponential loss of absorption at λ = 360 nm, and the refractive index of the PVA:FeCl3 films decreases significantly during UV irradiation (ΔnD = −0.09). The effects of crosslinking have been studied using the sol–gel technique, which revealed high gel contents due to doping and UV‐exposure. Photolithographic patterning of doped PVA films using a medium‐pressure mercury‐vapor UV source has been carried out, leading to good contrast behavior before and after development in aqueous media. A photobleaching effect was observed, therefore the curing of thicker films is feasible. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

show abstract

Photoreduction of iron(III) chloride in aqueous media

Abstract: A study of the photoreduction of iron(II1) to iron(I1) in aqueous iron(m) chloride as a function of hydrochloric acid and chloride ion concentrations indicates that Fe3fOH-, and not Fe3+Cl-, is the photoactive species.

Cited by 8 publications

References 0 publications

Primary Photochemical Reactions in the Photo-Fenton System with Ferric Chloride. 1. A Case Study of Xylidine Oxidation as a Model Compound

Primary Photochemical Reactions in the Photo-Fenton System with Ferric Chloride. 1. A Case Study of Xylidine Oxidation as a Model Compound

The Charge Transfer Photochemistry of the Hexaaquoiron(III) Ion, the Chloropentaaquoiron(III) Ion, and the µ-Dihydroxo Dimer Explored with tert-Butyl Alcohol Scavenging

UV crosslinking of Fe³⁺‐doped poly(vinyl alcohol)—Characterization of optical properties and swelling behavior

Contact Info

Product

Resources

About

Photoreduction of iron(III) chloride in aqueous media

Abstract: A study of the photoreduction of iron(II1) to iron(I1) in aqueous iron(m) chloride as a function of hydrochloric acid and chloride ion concentrations indicates that Fe3fOH-, and not Fe3+Cl-, is the photoactive species.

Cited by 8 publications

References 0 publications

Primary Photochemical Reactions in the Photo-Fenton System with Ferric Chloride. 1. A Case Study of Xylidine Oxidation as a Model Compound

Primary Photochemical Reactions in the Photo-Fenton System with Ferric Chloride. 1. A Case Study of Xylidine Oxidation as a Model Compound

The Charge Transfer Photochemistry of the Hexaaquoiron(III) Ion, the Chloropentaaquoiron(III) Ion, and the µ-Dihydroxo Dimer Explored with tert-Butyl Alcohol Scavenging

UV crosslinking of Fe3+‐doped poly(vinyl alcohol)—Characterization of optical properties and swelling behavior

Contact Info

Product

Resources

About

UV crosslinking of Fe³⁺‐doped poly(vinyl alcohol)—Characterization of optical properties and swelling behavior