Iodometric Methods

Johnson, Ralph M.; Siddiqi, I.

doi:10.1016/b978-0-08-015586-9.50007-7

Cited by 7 publications

(2 citation statements)

References 67 publications

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“…The mixture was stirred for 20 min, and the solvent layers were separated. The aqueous layer was extracted again with dichloromethane (20 mL), and the hydrogen peroxide content of this layer was determined by iodometry . Iodometric titration gave a peroxide content of 0.0023 mmol/mg (96.5%/mol) for the peroxo complex.…”

Section: Methodsmentioning

confidence: 99%

Valence Tautomerism and Metal-Mediated Catechol Oxidation for Complexes of Copper Prepared with 9,10-Phenanthrenequinone

et al. 2001

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Bis(pyridine)(9,10-phenanthrenequinone)(9,10-phenanthrenediolato)copper(II), Cu(py)(2)(PhenCat)(PhenBQ), has been prepared by treating copper metal with 9,10-phenanthrenequinone in pyridine solution. In dilute solution, both Cu(py)(2)(PhenCat)(PhenBQ) and the related complex Cu(tmeda)(PhenCat)(PhenBQ) lose PhenBQ to form Cu(II)L(2)(PhenCat), where L(2)= tmeda, 2 py. EPR spectra recorded at temperatures between 300 and 77 K reveal the presence of species with radical and metal localized spins together at equilibrium. Equilibria between Cu(II)L(2)(PhenCat) and Cu(I)L(2)(PhenSQ) redox isomers are solvent dependent, with a shift to higher temperature for polar solvents. Both complexes are oxygen sensitive, reacting with dioxygen to give complexes of diphenic acid. Structural characterization on products obtained with tmeda show that dioxygen insertion across the C-C bond within the chelate ring leads to dimeric products with adjacent Cu(II) ions bridged by diphenate ligands. The addition of O(2) to Cu(tmeda)(PhenCat) in acetonitrile solution at 0 degrees C appears to form a peroxo complex, tentatively identified as Cu(tmeda)(O(2))(PhenQ) on the basis of iodometric titration, as the precursor to the diphenate complex.

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Section: Methodsmentioning

confidence: 99%

Valence Tautomerism and Metal-Mediated Catechol Oxidation for Complexes of Copper Prepared with 9,10-Phenanthrenequinone

et al. 2001

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“…The well-known iodometric titration method was used to determine the content of peroxo-groups . In general, 50.0 mg of OxDexM(n) was dissolved in 5 mL of deionized water.…”

Section: Experimental Sectionmentioning

confidence: 99%

No Catalyst Added Hydrogen Peroxide Oxidation of Dextran: An Environmentally Friendly Route to Multifunctional Polymers

Пронина

Vorotnikov

Pozmogova

et al. 2020

ACS Sustainable Chem. Eng.

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The paper demonstrates a "greener" oxidation of dextran polymer of various molecular masses, the component of many industrially and pharmaceutically important materials, by aqueous H 2 O 2 in a no catalyst added setting that produced a multifunctional oxidized dextran. Specifically, on the top of common functional groups (hydroxo, carbonyl, and carboxylic acids), the freshly peroxide oxidized dextran had also a significant number of peroxo-groups, which endowed the polymer with significant cytotoxic properties, as demonstrated on a larynx carcinoma cell line. We also have shown that the peroxo-groups could be easily removed in an alkaline media to yield nontoxic oxidized dextran polymers.

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A practical way of grafting maleic anhydride onto polypropylene providing high anhydride contents without sacrificing excessive molar mass

Henry

Drooghaag

Rousseaux

et al. 2008

J. Polym. Sci. A Polym. Chem.

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This study reports a reactive extrusion process leading to very high levels of anhydride grafting (2.5-3 wt %) along polypropylene backbone without recovering grafted PP waxes at the die exit. Such high graftings are attainable without excessive degradation of the PP chain by using a brominated reagent. Simultaneously, this brominated reagent allows the tuning of the grafted PP crystallinity via epimerization of the PP backbone. Indeed, the synthesis of a mainly isotactic/atactic stereoblock polymer containing high levels of grafted succinic anhydride moieties is demonstrated by NMR and melting enthalpies recorded by DSC are definitely observed depressed and broadened. Grafting levels of around 3 wt % have been achieved and ascertained by both chemical titration and NMR spectroscopy. In addition, FTIR spectroscopy reveals an unusual observation: for the first time, only one single pair of symmetric and asymmetric carbonyl stretching bands are observed on those grafted PP, while, in other processes of anhydride grafting, those symmetric and asymmetric bands were both split in at least two bands. This suggests, for the here reported process, the absence of interacting grafted anhydride rings, i.e., absence of closely grafted anhydride moieties and absence of poly(maleic anhydride). All those observations support that this ''bromine route'' brings a really new grafting process for PP.

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Iodometric Methods

Cited by 7 publications

References 67 publications

Valence Tautomerism and Metal-Mediated Catechol Oxidation for Complexes of Copper Prepared with 9,10-Phenanthrenequinone

Valence Tautomerism and Metal-Mediated Catechol Oxidation for Complexes of Copper Prepared with 9,10-Phenanthrenequinone

No Catalyst Added Hydrogen Peroxide Oxidation of Dextran: An Environmentally Friendly Route to Multifunctional Polymers

A practical way of grafting maleic anhydride onto polypropylene providing high anhydride contents without sacrificing excessive molar mass

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