The Reaction of Trityl Salts with 2-Methyltetrahydrofuran and with Tetrahydrofuran

Dreyfuss, M. P.; Westfahl, J. C.; Dreyfuss, P.

doi:10.1021/ma60005a013

Cited by 56 publications

(23 citation statements)

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“…These are oxidation reactions which entail a fragmentation of the chain and the formation of aldehyde fragments (19). These aldehydic groups may also originate from a secondary polymerization process between the ~/ c a t i o n and the THF + molecules (20,21).…”

Section: Resultsmentioning

confidence: 99%

Polaromicrotribometric (PMT) and Spectroscopic (Infrared‐XPS) Study of the Formation and Modifications of Films Formed on a Polarized Platinum Electrode in THF ‐ LiClO4 Medium: II . Anodic Polarization

Tourillon

Dubois

Lacaze

1978

J. Electrochem. Soc.

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The surface changes occurring when a platinum electrode is anodieally polarized in THF-LiC104 or in THF-LiCIO~-9,10 dip'henylanthracene (DPA) are detected and investigated by means of polaromicrotribometry (PMT). The formation of a 'homogeneous film on the metal surface is associated with a very small value of the friction coefficient. The thickness of this film, designated by the general symbol PtITHF, LiC104, Oxl, may be adjusted from 100 to 5000A. It appears as a very pure variety of polyTHF, uncontaminated by the electrolyte. Multiple-reflection infrared spectroscopy and x-ray photoelectron spectroscopy (XPS) are used to determine its structure. Its formation results from the polymerization of THF via an ionic mechanism initiated by C104" or DPA" + radicals. It only occurs if the water content is less than 250 ppm. This film has well-defined physical properties: a marked hydrophobicity, very strong adherence on the platinum surface, and great homogeneity; although it is a nonconductor out of the solution, its porous structure makes it a conductor in electrolyte solution.The development of the technology in the area in microelectronics and, more recently, in that of integrated optics is more and more dependent on different methods of elaborating organic or mineral films (1). In the case of organic films, numerous techniques for deposition on metallic surfaces have been described. The most common methods are based on vapor deposition or sublimation (1), adsorption (2) or polymerization of an organic vapor subjected to electronic bombardment (3) or to an electric discharge (4). Electrochemical techniques can also be used for the elaboration of mineral or organic films, applicable to the previous areas. The film quality (purity, adherence, and homogeneity) depends on the Chemical system chosen, on the polarization conditions, and also on the choice of the chemical medium in which the electrode reaction is occurring. Generally speaking, it is possible to obtain an organic polymer film adsorbed on a metallic surface by oxidizing or reducing a compound which produces polymerizable radical or ionic species. The chosen reagent may either be a monomer dissolved in a solvent, or the solvent itself. The THF example belongs to this latter case, and in a previous work (5) we show that several mineral films are formed on the electrode under cathodic polarization.The polymerization of THF by chemical (6) or electrochemical (7-10) means has already been described in the literature, but it is only related to the formation of the dissolved polymer in solution. As far as we know, no study has been devoted to the phenomena which occur on the electrode surface for an anodic polarization.By using the PMT technique (11, 12), we have been a~ble to show important modifications of the platinum surface in the anodic zone. These are related to the appearance of a deposit which could not be detected * Electrochemical Society Active Member. by analysis of the i-E curves alone. This first observation is confirmed by means of other analytica...

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Section: Resultsmentioning

confidence: 99%

Polaromicrotribometric (PMT) and Spectroscopic (Infrared‐XPS) Study of the Formation and Modifications of Films Formed on a Polarized Platinum Electrode in THF ‐ LiClO4 Medium: II . Anodic Polarization

Tourillon

Dubois

Lacaze

1978

J. Electrochem. Soc.

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“…This might suggest 442 that in the former case perchlorate ion was not oxidized to form perchlorate radical which produced dihydrofuran, 3 because a colored polymer was formed from dihydrofuran as described by Dreyfuss, et a!. 9 These preliminary experiments implied that a direct electron-transfer initiation occurred in the THF-Bu4NC104-vinyl monomer system.…”

Section: Electro-initiated Living-polymerization Of Thf In the Presenmentioning

confidence: 89%

“…Dreyfuss reported that in the polymerization of THF by trityl cation, hydride ion was abstracted from THF to yield proton, which polymerized THF. 9 On the contrary, it was considered that in this system carbonium ions did not abstract a hydride ion, but attacked an oxygen atom of THF molecule resulting in oxonium ion. Though it is still ambiguous whether a THF molecule attacks a a-carbon of diphenylethylene cation-radical or Tables V-VII, low current efficiency at low conversion of poly-THF was due to mechanical losses of low-molecularweight polymer.…”

Section: Electro-initiated Living-polymerization Of Thf In the Presenmentioning

confidence: 99%

Anode-Initiated Polymerizations of Olefins and Tetrahydrofuran

Nakahama

Hashimoto

Yamazaki

1973

Polym J

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“…Carbenium and oxonium salts are also known to have a good chemical reactivity . However, they are relatively unstable, a fact that has prevented their development as photoinitiators.…”

Section: Introductionmentioning

confidence: 99%

Novel Dual‐Cure Initiating System for Cationic Polymerization of Epoxides

Maréchal

Allonas

Lecompère

et al. 2016

Macro Chemistry & Physics

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Pyrylium salts are found to be effective initiators for both photochemical and thermal cationic polymerization of epoxy resin. The photopolymerization results show that triphenylpyrylium salt derivatives are the most efficient structures. These compounds also exhibit some thermal reactivity at room temperature in the absence of light. However in such case, the gel time of the resin is quite high. Therefore, to speed up the thermal reaction, nucleophilic compounds are added as coinitiators, these compounds being known to yield a fast decomposition of pyrylium salts. This indeed increases the polymerization of epoxy resin at room temperature, opening the way to the development of quite efficient dual‐cure photochemical/thermal initiating system for cationic polymerization.

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The Reaction of Trityl Salts with 2-Methyltetrahydrofuran and with Tetrahydrofuran

Cited by 56 publications

References 0 publications

Polaromicrotribometric (PMT) and Spectroscopic (Infrared‐XPS) Study of the Formation and Modifications of Films Formed on a Polarized Platinum Electrode in THF ‐ LiClO4 Medium: II . Anodic Polarization

Polaromicrotribometric (PMT) and Spectroscopic (Infrared‐XPS) Study of the Formation and Modifications of Films Formed on a Polarized Platinum Electrode in THF ‐ LiClO4 Medium: II . Anodic Polarization

Anode-Initiated Polymerizations of Olefins and Tetrahydrofuran

Novel Dual‐Cure Initiating System for Cationic Polymerization of Epoxides

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