59110-36-0Relevant articles and documents
Synthesis of bifluorenes via cobalt halide radical coupling
Al-Afyouni, Malik H.,Huang, Tiffany A.,Hung-Low, Fernando,Bradley, Christopher A.
supporting information; experimental part, p. 3261 - 3265 (2011/07/08)
Reaction of in situ generated lithium fluorenide salts with cobalt chloride results in formation of the corresponding bifluorenes. The scope of fluorenes that can be coupled include those containing substituents amenable to polymerization for application
THERMALLY MODULATED ANTIOXIDANTS
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Page/Page column 49-50; 51, (2008/06/13)
Most carbon-centered free radical antioxidants are generated through hydrogen abstraction. Disclosed herein are a new class of antioxidant precursor compounds of the formula A-B, wherein upon exposure of the compounds to an increase in temperature, the co
Bond dissociation energies for radical dimers derived from highly stabilized carbon-centered radicals
Frenette, Mathieu,Aliaga, Carolina,Font-Sanchis, Enrique,Scaiano
, p. 2579 - 2582 (2007/10/03)
(Matrix Presented) The temperature dependence of the dissociation of dimers formed from highly stabilized carbon-centered radicals has been examined. Analysis of the data yields the bond dissociation energy (BDE) for the central head-to-head C-C bond in t
Correlation of Electron-Transfer Rate Constants of Carbinons with Their Oxidation Potentials and Basicities
Bordwell, Frederick G.,Bausch, Mark J.
, p. 1985 - 1988 (2007/10/02)
Acidity-oxidation-potential (AOP) values for seven 9-substituted fluorenide ions, 9-ArFl(1-), relative to that of fluorene, have revealed the presence of small radical-stabilizing effects for 4-MeO and 4-Me substitutents in the aryl ring and a 3-Me substituent in the fluorene ring and their absence for 3-Cl and 4-MeSO2 substituents in the aryl ring and 2-Br and 2-PhSO2 substituents in the fluorene ring.Measurements of redox potentials have shown that electron-transfer (eT(1-)) reactions of these 9-ArFl(1-) ions with 1,1-dinitrocyclohexane are endergonic by 6.6-13 kcal/mol.A Bronsted-type plot of log kobsd for these reactions vs. pKHA was linear with scatter.A Bronsted-type plot of log kobsd vs.Eox gave an improved plot (β = 1.04; R2 = 0.999) that covered a rate range of >1E5 and an Eox range of 7.3 kcal/mol.Mechanistic schemes are presented to account for the products formed in the eT(1-) reaction and to reconcile the strict linearity of the latter plot with the Marcus equation.
Broensted Correlations for Electron Transfer from Carbanions to Halomethyl Phenyl Sulfone and 1,1-Dinitroalkane-Type Acceptors
Bordwell, Frederick G.,Clemens, Anthony H.
, p. 2510 - 2516 (2007/10/02)
9-Substituted fluorenyl carbanions, 9-G-Fl(1-), with G = Ar or Me, have been dimerized to (9-G-Fl)2 by reaction in Me2SO solution with PhSO2CH2X and R2C(NO2)X electron acceptors.Rate measurements revealed the following electron-accepting abilities: c-C6H10(NO2)2 > Me2C(NO2)2 > PhSO2CH2Br, PhSO2CH2I > c-C6H10(NO2)CN > c-C6H10(NO2)SO2C7H7 > Me2C(NO2)SO2C7H7 > PhSO2CH2Cl.The rate-limiting step in these reactions is electron transfer from 9-G-Fl(1-) to the electron acceptor.Plots of log k vs. pKa of 9-G-FlH are linear with a slope near unity for all seven electron acceptors studied.We conclude that a Broensted β of unity is characteristic of electron transfer from carbanions to electron acceptors in Me2SO solution.This is interpreted to mean that the changes in ΔG0 brought about by changes in the basicity of the carbanion are matched by changes in ΔG(excit.), which correspond to the difference in the energy gap between the HOMO of the donor and the LUMO of the acceptor.
Correlation between the Basicity of Carbanions and Their Ability to Transfer an Electron
Bordwell, Frederick G.,Clemens, Anthony H.
, p. 1035 - 1037 (2007/10/02)
In Me2SO solution electron transfer from 9-arylfluorenyl carbanions, 9-ArFl-, to electron acceptors including PhSO2CH2Br, PhSO2CH2I, or R2C(NO2)2 follows second-order kinetics and results in the formation of dimers, (9-ArFl-)2, in high yields.Broensted-type correlations of log k2 vs. pKa (Table I) show that these electron-transfer processes have a much higher sensitivity to changes in 9-ArFl- ion basicity (βNu>1.0) than do SN2 reactions of RX with these carbanions (βNu=0.3-0.5).
REACTIVITY OF ORGANOTIN COMPOUNDS. XXII. REACTIONS OF ORGANOTIN COMPOUNDS WITH o-NITROBENZENESULFENYL CHLORIDE
Kashin, A. N.,Bumagin, N. A.,Beletskaya, I. P.,Reutov, O. A.
, p. 2190 - 2195 (2007/10/02)
The reaction of organotin compounds RSnMe3 and of cyclohexenyloxytriethyltin (VII) with o-nitrobenzenesulfenyl chloride (VIII) in methylene chloride under vacuum conditions was investigated.In the reactions of the organotin compounds (IV - VII) with o-nitrobenzenesulfenyl chloride (VIII) the corresponding sulfides are formed with quantitative yields.In the reactions ofcompounds (I) and (II) with (VIII) sulfides, fluorenyl dimers, and (o-NO2C6H4S)2 are obtained, and the yield of the sulfides decreases in the presence of atmospheric oxygen.In the reaction of compound (III) with (VIII) only the oxidation products (9-C6H5C13H8)2 and (o-NO2C6H4S)2 are formed.Possible reaction mechanisms are discussed.
