Bremsted acid

To qualitatively test for Bronsted acidity using the colorimetric method, 50 mg of the zeolite sample was pretreated at 300°C under vacuum for approximately 12 hrs. 1 mL of a dilute solution of retinol (Aldrich) or retinyl acetate (Aldrich) in dry hexane was injected onto the activated zeolite (10,11). A color change to blue indicated the presence of Bremsted acid sites. 

Similarly, a Bremsted-acid-promoted rearrangement using 10mol% p-toluene-sulfonic acid in acetonitrile/water (10 1) at 65 °C was also reported [58]. 

Ramachandran and Pratihar [32] also reported interesting effects of Lewis acid and Bremsted acid toward the reaction with crotyl boron reagent 39. In the presence of 20mol% of In(OTf)3 or TfOH, the reaction of (E)-39 with aliphatic... 

Bremsted—Lowry In 1923 J. N. Brgnsted and T. M. Lowry independently1 suggested that acids be... 

Efficient catalysts at pH 7.0 are shown to possess piCa values around 7 because a higher percentage of the acid is unionized and a higher percentage of the base is protonated. Therefore, the acid-base pair is more reactive, which can be measured as lower Bremsted values. This explains the widespread use of histidine (pK, = 6.5) as an acid-base catalyst in enzymes. 

Olah, G. A. Prakash, G. K. S. Sommer, J. Superacids John Wiley Sons New York, 1985. Bremsted superacids are acids stronger than 100% H2SO4, while Lewis superacids are stronger than AICI3 (reference 226). 

Proton addition is one of the most simple and straightforward methods for the initiation of cationic polymerization. Bremsted adds are effective for this purpose. However, if we use a weak Bronsted acid, i.e. a conjugate acid of a strong nucleophilic anion, the addition of a Lewis acid is necessary to establish a reversible activation of a covalent end group for effective propagation. On the other hand, if we use a strong... 

Bremsted-Lowiy acid A proton (H ion) donor. Bronsted-Lowiy base A proton (H" " ion) acceptor, buffer A solution that resists pH change by neutralizing added acid or added base. 

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