Unexpected Radical Telomerisation of Vinylidene Fluoride with 2-Mercaptoethanol

The radical telomerisation of vinylidene fluoride (VDF) with 2-mercaptoethanol as chain transfer agent (CTA) was studied to synthesise fluorinated telomers which bear a hydroxy end-group, such as H(VDF)nS(CH2)2OH, under thermal (di-tert-butyl peroxide as the initiator) or photochemical initiations. A careful structural study of a typical H-VDF-S(CH2)2OH telomer was performed by 1H and 19F NMR spectroscopy. These analytical methods allowed us to explore the selective addition of the thiyl radical onto the hydrogenated side of VDF, and the telomer containing one VDF unit was obtained selectively. Surprisingly, for higher [VDF]o initial concentrations, a monoadduct telomer was produced as well as PVDF homopolymer. This feature was related to the fast consumption of the CTA. The kinetics of radical telomerisation led to a quite high transfer constant of the CTA (40 at 140 °C) that evidences the formation of a monoadduct as the only telomer formed.

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Kinetics of radical telomerization of vinylidene fluoride in the presence of CCl3Z chain transfer agents

Journal of Fluorine Chemistry ◽

10.1016/j.jfluchem.2006.11.004 ◽

2007 ◽

Vol 128 (2) ◽

pp. 144-149 ◽

Cited By ~ 14

Author(s):

Michel Duc ◽

Bruno Ameduri ◽

Ghislain David ◽

Bernard Boutevin

Keyword(s):

Chain Transfer ◽

Vinylidene Fluoride ◽

Radical Telomerization ◽

Kinetics Of ◽

Transfer Agents

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Asymetrical Dimer - allyl-palladiu Complexes II. Data from Infrared Spectra and Chemical Behaviour

Revista de Chimie ◽

10.37358/rc.08.7.1888 ◽

2008 ◽

Vol 59 (7) ◽

Author(s):

Maria Maganu ◽

Filip Chiraleu ◽

Constantin Draghici ◽

Gheorghe Mihai

Keyword(s):

Carbon Monoxide ◽

Nmr Spectroscopy ◽

1H Nmr ◽

Infrared Spectra ◽

Analytical Methods ◽

1H Nmr Spectroscopy ◽

Chemical Behaviour ◽

The Asymmetry ◽

Pd Complexes

The previous data obtained by 1H-NMR spectroscopy established the existence of an asymmetry of the bond between Pd and p-allylic groups, even in the p-allyl-Pd complexes dimers which are considered usually symmetric dimers. The asymmetry of the bond depends by the substitutes of the allylic group. Other analytical methods were investigated for additional proof of the obtained results. Thus, this paper discusses how this asymmetry would be reflected in the infrared spectra and in the reaction of the complexes with carbon monoxide.

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Catalytic activity of rhodium(I) complexes containing (ω-trimethylsilylalkyl)diphenylphosphines

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19802219 ◽

1980 ◽

Vol 45 (8) ◽

pp. 2219-2223 ◽

Cited By ~ 6

Author(s):

Marie Jakoubková ◽

Martin Čapka

Keyword(s):

Catalytic Activity ◽

Nmr Spectroscopy ◽

Ir Spectroscopy ◽

Electron Density ◽

Phosphorus Atom ◽

Proton Acceptor ◽

Trimethylsilyl Group ◽

Kinetics Of

Kinetics of homogenous hydrogenation of 1-heptene catalysed by rhodium(I) complexes prepared in situ from μ,μ'-dichloro-bis(cyclooctenerhodium) and phosphines of the type RP(C6H5)2 (R = -CH3, -(CH2)nSi(CH3)3; n = 1-4) have been studied. The substitution of the ligands by the trimethylsilyl group was found to increase significantly the catalytic activity of the complexes. The results are discussed in relation to the electron density on the phosphorus atom determined by 31P NMR spectroscopy and to its proton acceptor ability determined by IR spectroscopy.

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The Application of NMR Spectroscopy and Chemometrics in Authentication of Spices

Molecules ◽

10.3390/molecules26020382 ◽

2021 ◽

Vol 26 (2) ◽

pp. 382

Author(s):

Barbara Pacholczyk-Sienicka ◽

Grzegorz Ciepielowski ◽

Łukasz Albrecht

Keyword(s):

Quality Assurance ◽

Nmr Spectroscopy ◽

Sample Preparation ◽

Bioactive Compounds ◽

Analytical Methods ◽

Structural Information ◽

Chemometric Analysis ◽

Spectroscopic Methods ◽

Regular Consumption ◽

No Sample Preparation

Spices and herbs are among the most commonly adulterated food types. This is because spices are widely used to process food. Spices not only enhance the flavor and taste of food, but they are also sources of numerous bioactive compounds that are significantly beneficial for health. The healing effects of spices are connected with their antimicrobial, anti-inflammatory and carminative properties. However, regular consumption of adulterated spices may cause fatal damage to our system because adulterants in most cases are unhealthy. For that reason, the appropriate analytical methods are necessary for quality assurance and to ensure the authenticity of spices. Spectroscopic methods are gaining interest as they are fast, require little or no sample preparation, and provide rich structural information. This review provides an overview of the application of NMR spectroscopy combined with chemometric analysis to determine the quality and adulteration of spices.

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