An Acidity Scale of Triazolium-Based NHC Precursors in DMSO

2017 ◽  
Vol 82 (18) ◽  
pp. 9675-9681 ◽  
Author(s):  
Zhen Li ◽  
Xin Li ◽  
Jin-Pei Cheng
Keyword(s):  
Acidity Scale

An acidity scale, [H+]hv, for proton quenching of excited states

1989 ◽  
Vol 67 (2) ◽  
pp. 227-238 ◽  
Author(s):  
J. A. Pincock ◽  
P. R. Redden
Keyword(s):  
Excited State ◽  
Fluorescence Quenching ◽  
Excited States ◽  
Benzyl Alcohols ◽  
Fluorescent Indicator ◽  
Quenching Of Fluorescence ◽  
Acidity Scale

An acidity scale for excited state protonation kinetics in 20% ethanol:80% aqueous sulfuric has been developed using 1-cyano-naphthalene as a fluorescent indicator. The utility of this new scale is demonstrated using the proton quenching of fluorescence of a variety of chromophores. These include 1- and 2-cyanonaphthalenes, 1- and 2-methoxynaphthalenes, benzyl alcohols, toluenes, and 2-vinylnaphthalene. Keywords: acidity scale, fluorescence quenching, excited state basicity.

Standardization of acidity scale in a toluene–ethanol medium

2011 ◽  
Vol 66 (2) ◽  
pp. 125-130
Author(s):  
G. N. Nechepurenko ◽  
I. M. Kutyrev ◽  
Yu. A. Gaidukova ◽  
N. N. Basargin
Keyword(s):  
Ethanol Medium ◽  
Acidity Scale

scholarly journals Voltammetric Perspectives on the Acidity Scale and H+/H2 Process in Ionic Liquid Media

2018 ◽  
Vol 11 (1) ◽  
pp. 397-419 ◽  
Author(s):  
Cameron L. Bentley ◽  
Alan M. Bond ◽  
Jie Zhang
Keyword(s):  
Chemical Reactivity ◽  
Electrode Reaction ◽  
Structure And Function ◽  
Electrochemical Characteristics ◽  
Liquid Media ◽  
Physical Chemical ◽  
Voltammetric Studies ◽  
And Function ◽  
Acidity Scale ◽  
Molecular Solvents

Nonhaloaluminate ionic liquids (ILs) have received considerable attention as alternatives to molecular solvents in diverse applications spanning the fields of physical, chemical, and biological science. One important and often overlooked aspect of the implementation of these designer solvents is how the properties of the IL formulation affect (electro)chemical reactivity. This aspect is emphasized herein, where recent (voltammetric) studies on the energetics of proton (H+) transfer and electrode reaction mechanisms of the H+/H2 process in IL media are highlighted and discussed. The energetics of proton transfer, quantified using the p Ka (minus logarithm of acidity equilibrium constant, Ka) formalism, is strongly governed by the constituent IL anion, and to a lesser extent, the IL cation. The H+/H2 process, a model inner-sphere reaction, also displays electrochemical characteristics that are strongly IL-dependent. Overall, these studies highlight the need to carry out systematic investigations to resolve IL structure and function relationships in order to realize the potential of these diverse and versatile solvents.

A Comprehensive Self-Consistent Spectrophotometric Acidity Scale of Neutral Brønsted Acids in Acetonitrile

2006 ◽  
Vol 71 (7) ◽  
pp. 2829-2838 ◽  
Author(s):  
Agnes Kütt ◽  
Ivo Leito ◽  
Ivari Kaljurand ◽  
Lilli Sooväli ◽  
Vladislav M. Vlasov ◽  
...  
Keyword(s):  
Bronsted Acids ◽  
Self Consistent ◽  
Acidity Scale

Spectrophotometric Acidity Scale of Strong Neutral Brønsted Acids in Acetonitrile

1998 ◽  
Vol 63 (22) ◽  
pp. 7868-7874 ◽  
Author(s):  
Ivo Leito ◽  
Ivari Kaljurand ◽  
Ilmar A. Koppel ◽  
Lev M. Yagupolskii ◽  
Vladislav M. Vlasov
Keyword(s):  
Bronsted Acids ◽  
Acidity Scale

ChemInform Abstract: An Acidity Scale, (H+)hv, for Proton Quenching of Excited States

ChemInform ◽  
1987 ◽  
Vol 18 (33) ◽  
Author(s):  
W. BRANDON ◽  
A. L. PINCOCK ◽  
J. A. PINCOCK ◽  
P. REDDEN ◽  
C. SEHMBEY
Keyword(s):  
Excited States ◽  
Acidity Scale

Carbenium and carbonium ions in liquid- and solid-superacid-catalyzed activation of small alkanes

2000 ◽  
Vol 72 (12) ◽  
pp. 2309-2318 ◽  
Author(s):  
J. Sommer ◽  
R. Jost
Keyword(s):  
Isotopic Labeling ◽  
Oil Refinery ◽  
Basic Knowledge ◽  
Physical Organic Chemistry ◽  
True Nature ◽  
Physical Organic ◽  
Carbonium Ions ◽  
Acid Catalyzed ◽  
Hydrocarbon Reactions ◽  
Acidity Scale

Acid-catalyzed hydrocarbon reactions involve by far the largest amount of catalyst and the largest volume of transformation in oil refinery and chemical industry. However, despite the general agreement on the carbocationic nature of the reaction intermediates, the initial steps and the true nature of the cations on the surface are still open to debate. On these points our basic knowledge has gained enormously from landmark experiments in physical organic chemistry with spectroscopic observations using liquid superacids as solvents. As the range of superacidity covers over 11 logarithmic units of the Hammett acidity scale, the mechanistic behavior of small alkanes vary accordingly. This allows for comparison with strong solid acids such as zeolite or others used in industry. Isotopic labeling of the alkane and the acids is a powerful tool used to understand the nature of the intermediates, as well as the reaction mechanism in which carbenium and carbonium ions intervene.

An acidity scale, [H+]hv, for proton quenching of excited states in aqueous perchloric acid

1989 ◽  
Vol 67 (4) ◽  
pp. 710-719 ◽  
Author(s):  
J. A. Pincock ◽  
P. R. Redden
Keyword(s):  
Excited State ◽  
Activity Coefficient ◽  
Excited States ◽  
Perchloric Acid ◽  
Acidity Function ◽  
Quenching Rate ◽  
Benzyl Alcohols ◽  
Fluorescent Indicator ◽  
Aqueous Perchloric Acid ◽  
Acidity Scale

An acidity scale for excited state protonation kinetics in aqueous perchloric acid has been developed using 1-cyanonaph-thalene as a fluorescent indicator. A comparison of the quenching rate constants obtained using this scale is made with both the more general excess acidity function, X, and the transition state activity coefficient approach. A variety of chromophores were studied including 1- and 2-cyanonaphthalenes, 1- and 2-methoxynaphthalenes, benzyl alcohols, toluenes, benzonitriles, and 2-vinylnaphthalene. Keywords: acidity scale, proton fluorescence quenching.

scholarly journals THE RELATIVE ACID STRENGTHS OF SUBSTITUTED PICRIC ACIDS

1964 ◽  
Vol 42 (5) ◽  
pp. 1106-1109 ◽  
Author(s):  
John W. Elder ◽  
Raymond P. Mariella
Keyword(s):  
Acetic Acid ◽  
Inorganic Acids ◽  
Aqueous Method ◽  
Aqueous Conditions ◽  
Acidity Scale ◽  
Relative Acidity

The relative acidity of substituted picric acids has been determined using special non-aqueous titration techniques. Other organic and inorganic acids, whose acidities in water are well known, were also determined using this non-aqueous method. A correlation of the relative acidities of known acids in water with the relative acidities of these same acids, as measured under the non-aqueous conditions used, was excellent. Using this technique a single relative acidity scale was determined ranging from acids as strong as perchloric to acids as weak as acetic acid.

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