Chemical transformation of ferrihydrite coating into green rust followed by Raman and X-ray photoelectron spectroscopies

A method has been worked out for the reproducible preparation of Green Rust substances involving SO42-, Cl-, Br-, and I- anions. The chemical composition of the substances prepared has been followed in dependence on the synthesis conditions. The powder X-ray and electron diffraction patterns and infrared and Moessbauer spectra have been measured and discussed.

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Green rust as a precursor for magnetite: an in situ synchrotron based study

Mineralogical Magazine ◽

10.1180/minmag.2008.072.1.201 ◽

2008 ◽

Vol 72 (1) ◽

pp. 201-204 ◽

Cited By ~ 40

Author(s):

A. Sumoondur ◽

S. Shaw ◽

I. Ahmed ◽

L. G. Benning

Keyword(s):

Direct Evidence ◽

Green Rust ◽

Stable Phase ◽

X Ray Diffraction ◽

Time Resolved ◽

X Ray ◽

Subsequent Transformation ◽

Rapid Formation ◽

Reaction Proceeds

AbstractIn this study, direct evidence for the formation of magnetite via a green rust intermediate is reported. The Fe(II) induced transformation of ferrihydrite, was quantified in situ and under O2-free conditions using synchrotron-based time-resolved energy dispersive X-ray diffraction. At pH 9 and Fe(II)/Fe(III) ratios of 0.5 and 1, rapid growth (6 min) of sulphate green rust and its subsequent transformation to magnetite was observed. Electron microscopy confirmed these results, showing the initial rapid formation of hexagonal sulphate green rust particles, followed by the corrosion of the green rust as magnetite growth occurred, indicating that the reaction proceeds via a dissolution-reprecipitation mechanism. At pH 7 and Fe(II)/Fe(III) ratio of 0.5, sulphate green rust was the stable phase, with no transformation to magnetite.

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Sub-100-nm Pattern Formation through Selective Chemical Transformation of Self-Assembled Monolayers by Soft X-ray Irradiation

Langmuir ◽

10.1021/la0487085 ◽

2004 ◽

Vol 20 (16) ◽

pp. 6964-6964 ◽

Cited By ~ 2

Author(s):

Young-Hye La ◽

Yu Jin Jung ◽

Hyun Ju Kim ◽

Tai-Hee Kang ◽

Kyuwook Ihm ◽

...

Keyword(s):

Pattern Formation ◽

Chemical Transformation ◽

Self Assembled Monolayers ◽

X Ray ◽

Assembled Monolayers ◽

Selective Chemical ◽

Self Assembled

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Operando Soft X-ray Spectroscopy Probing Chemical Transformation in Space and Time

Microscopy and Microanalysis ◽

10.1017/s1431927621013301 ◽

2021 ◽

Vol 27 (S2) ◽

pp. 61-62

Author(s):

Yi-De Chuang ◽

Per-Anders Glans ◽

Wanli Yang ◽

Jinghua Guo

Keyword(s):

Chemical Transformation ◽

X Ray ◽

Space And Time

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Studies of Australian soft corals. XXXII. The structure determination of degraded xenicin-type diterpenes from several Efflatounaria species

Australian Journal of Chemistry ◽

10.1071/ch9832279 ◽

1983 ◽

Vol 36 (11) ◽

pp. 2279 ◽

Cited By ~ 5

Author(s):

BF Bowden ◽

JC Coll ◽

VA Patrick ◽

DM Tapiolas

Keyword(s):

Single Crystal ◽

Chemical Transformation ◽

Structure Determination ◽

High Field ◽

Soft Corals ◽

X Ray ◽

The Third

Three new diterpenes have been isolated from soft corals of the genus Efflatounaria (Coelenterata, Octocorallia, Alcyonacea, Xeniidae). The structure of the first compound (4) was elucidated on the basis of high-field 1H n.m.r. spectroscopy while that of the second metabolite (5) was determined by single-crystal X-ray analysis. The third diterpene (6) was structurally related to (5), and its structure was confirmed by chemical transformation. All three diterpenes can be derived from xenicin-type precursors, by cleavage and recyclization.

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Chemical transformation of 1,2-oxazinochlorin derivatives: synthesis and X-ray crystal structure of a novel porphyrin-porphyrin dimer with a condensed cyclohexane ring

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424607000059 ◽

2007 ◽

Vol 11 (01) ◽

pp. 31-41 ◽

Cited By ~ 1

Author(s):

Yuliya V. Morozova ◽

Dmitry V. Yashunsky ◽

Zoya A. Starikova ◽

Gelii V. Ponomarev

Keyword(s):

Crystal Structure ◽

Single Crystal ◽

Chemical Transformation ◽

Trifluoroacetic Acid ◽

Ring Opening ◽

Nickel Complex ◽

Cyclohexane Ring ◽

X Ray ◽

Reagent Treatment ◽

Porphyrin Dimer

Base-assisted ring opening in 1,2-oxazinochlorin derivatives led selectively to the corresponding meso-cyanohydroxychlorin derivatives. The latter could then undergo acid-mediated carbocation formation followed by nucleophilic treatment to give different products, depending on the nature of the nucleophile reagent. Treatment of (E)- and/or (Z)-2-ethylidene-3-hydroxy-5-cyano-3,7,8,12,13,17,18-heptaethylchlorin nickel complex with a mixture of 5% trifluoroacetic acid and dichloromethane yielded a novel type porphyrin-porphyrin dimer with a condensed cyclohexane ring in an almost quantitative yield. The structure of this dimer was determined by single crystal X-ray analysis.

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