2378-02-1Relevant articles and documents
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Dear,R.E.A.
, p. 361 - 362 (1970)
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Monitoring of biological one-electron reduction by 19F NMR using hypoxia selective activation of an 19F-labeled indolequinone derivative
Tanabe, Kazuhito,Harada, Hiroshi,Narazaki, Michiko,Tanaka, Kazuo,Inafuku, Kenichi,Komatsu, Hirokazu,Ito, Takeo,Yamada, Hisatsugu,Chujo, Yoshiki,Matsuda, Tetsuya,Hiraoka, Masahiro,Nishimoto, Sei-Ichi
, p. 15982 - 15983 (2009)
(Chemical Equation Presented) Biological reduction of fluorine-labeled indolequinone derivative (IQ-F) was characterized by 19F NMR for quantitative molecular understanding. The chemical shift change in 19F NMR allowed monitoring of the enzymatic reductio
A janus-headed lewis superacid: Simple access to, and first application of Me3Si-F-Al(ORF)3
Rohde, Michael,Muller, Lutz O.,Himmel, Daniel,Scherer, Harald,Krossing, Ingo
supporting information, p. 1218 - 1222 (2014/04/03)
Upon reaction of gaseous Me3SiF with the in situ prepared Lewis acid Al(ORF)3, the stable ion-like silylium compound Me3Si-F-Al(ORF)3 1 forms. The Janusheaded 1 is a readily available smart Lewis acid that differentiates between hard and soft nucleophiles, but also polymerizes isobutene effectively. Thus, in reactions of 1 with soft nucleophiles (Nu), such as phosphanes, the silylium side interacts in an orbital-controlled manner, with formation of [Me3Si-Nu]+ and the weakly coordinating [F-Al(ORF)3]-or [(FRO)3Al-F-Al(ORF)3]- anions. If exchanged for hard nucleophiles, such as primary alcohols, the aluminum side reacts in a charge-controlled manner, with release of FSiMe3 gas and formation of the adduct R(H)O-Al(ORF)3. Compound 1 very effectively initiates polymerization of 8 to 21 mL of liquid C4H8 in 50 mL of CH2Cl2 already at temperatures between -57 and -30 8C with initiator loads as low as 10 mg in a few seconds with 100 % yield but broad polydispersities.
Hydrogen bonding between solutes in solvents octan-1-ol and water
Abraham, Michael H.,Gola, Joelle M. R.,Cometto-Muniz, J. Enrique,Acree, William E.
experimental part, p. 7651 - 7658 (2011/02/25)
The 1:1 equilibrium constants, K, for the association of hydrogen bond bases and hydrogen bond acids have been determined by using octan-1-ol solvent at 298 K for 30 acid-base combinations. The values of K are much smaller than those found for aprotic, rather nonpolar solvents. It is shown that the log K values can satisfactorily be correlated against αH 2?βH2, where αH 2 and βH2 are the 1:1 hydrogen bond acidities and basicities of solutes. The slope of the plot, 2.938, is much smaller than those for log K values in the nonpolar organic solvents previously studied. An analysis of literature data on 1:1 hydrogen bonding in water yields a negative slope for a plot of log K against αH 2?βH2, thus showing how the use of very strong hydrogen bond acids and bases does not lead to larger values of log K for 1:1 hydrogen bonding in water. It is suggested that for simple 1:1 association between monofunctional solutes in water, log K cannot be larger than about -0.1 log units. Descriptors have been obtained for the complex between 2,2,2-trifluoroethanol and propanone, and used to analyze solvent effects on the two reactants, the complex, and the complexation constant.
