- RETRACTED ARTICLE: Mechanical activation of catalysts for C-C bond forming and anionic polymerization reactions from a single macromolecular reagent
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Coupling of pyridine-capped poly(methyl acrylate)s, PyPM (where M corresponds to the number average molecular weight in kDa), to the SCS-cyclometalated dipalladium complex [(1)(CH3CN)2] afforded organometallic polymers [(1)(PyPM)2] with a concomitant doubling in molecular weight. Ultrasonication of solutions containing [(1)(PyPM)2] effected the mechanical scission of a palladium-pyridine bond, where the liberated PyPM was trapped with excess HBF4 as the corresponding pyridinium salt, harnessed to effect the stoichiometric deprotonation of a colorimetric indicator, or used to catalyze the anionic polymerization of α-trifluoromethyl-2,2,2- trifluoroethyl acrylate. The mechanically induced chain scission also unmasked a catalytically active palladium species which was used to facilitate carbon-carbon bond formation between benzyl cyanide and N-tosyl imines. Spectroscopic and macromolecular analyses as well as a series of control experiments demonstrated that the aforementioned structural changes were derived from mechanical forces that originated from ultrasound-induced dissociation of the polymer chains connected to the aforementioned Pd complexes.
- Tennyson, Andrew G.,Wiggins, Kelly M.,Bielawski, Christopher W.
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supporting information; experimental part
p. 16631 - 16636
(2011/02/23)
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- Micellar catalysis in the systems arylamine-diphenylamine-NO 2-
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By methods of UV and IR spectroscopy and thermogravimetry reactions of diazotizaion and azo coupling were studied in the systems of primary arylamine (p-nitro-, p-carboxy- and p-sulfoaniline)- diphenylamine -nitrite ion in water and micellar media on the basis of surfactants. The micellar catalysis effect of sodium dodecylsulfate in the micellar media was revealed. Rate of diazotization was shown to be independent of the surfactants of various types. Formation of ionic associates of azo dyes with dodecylsulfate anions in premicellar region was established and physicochemical characteristics of the associates were estimated.
- Doronin, S. Yu.,Chernova
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scheme or table
p. 2019 - 2024
(2009/04/12)
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