Acid/base reactivity

The utility of acid-base titrimetry improved when NaOH was first introduced as a strong base titrant in 1846. In addition, progress in synthesizing organic dyes led to the development of many new indicators. Phenolphthalein was first synthesized by Bayer in 1871 and used as a visual indicator for acid-base titrations in 1877. Other indicators, such as methyl orange, soon followed. Despite the increasing availability of indicators, the absence of a theory of acid-base reactivity made selecting a proper indicator difficult. 

Experimental pKa data suggests that simple alkyl groups all affeet acid-base reactivity in roughly the same way. What is more, this universal alkyl effect is roughly equivalent to the effect of a hydrogen atom. For example, the difference in pKa between water and ethanol is approximately the same as that between formic acid and propanoic acid (see table at right). 

Acid-base reactivity is an important property of oxide catalysts, and its control is of interest in surface chemistry as well as being of importance in industrial applications. The exposed cations and anions on oxide surfaces have long been described as acid-base pairs. The polar planes of ZnO showed dissociative adsorption and subsequent decomposition of methanol and formic acid related with their surface acid-base properties[3]. Further examples related to the topic of acid-base properties have been accumulated to date[ 1,4-6]. 

Schmittel and Burghart (1997) had published a well-structured review on cation-radical chemistry. The review gave a general picture of the cation-radical nature compiling data of those days. This section scrutinizes data relevant to acid-base reactivity of organic ion-radicals. 

A convenient tool for the analysis of substituent effects on the acid-base reactivity of homogeneous families of compounds is the comparison of their... 

This reaction and the corresponding one for anions turn out to be useful prototypes for a number of Lewis acid properties of fundamental importance in aquatic chemistry, bioinorganic chemistry, and inorganic chemistry itself Six broadly applicable categories of the acid-base reactivity of cations and anions have been defined (Table 1) ... 

Anhydride (-C-C(0)-0-C(0)-C-) Amide (-NH-C(O)-) SUoxane (-R3Si-0-) Chain flexibility, water sensitive (especially for short aliphatic chains) Chain rigidity, crystalline, water sensitive Chain flexibility and low Tg (especially for small substituents), stable toward oxidation, acid/base reactive... 

Another way to predict acid-base reactivity is to remember that the products of an acid-base reaction must be more stable than the reactants. In other words, the product acid must be weaker and less reactive than the starting acid, and the product base must be weaker and less reactive than the starting base. In the reaction of acetic acid with hydroxide ion, for example, the product conjugate acid (Hproduct conjugate base (CHsCOO") is weaker than the starting base (OH ). 

Bickmore, B. R., Rosso, K. M., Nagy, K. L., Cygan, R. T., and Tadanier, C. J. (2003). Ab initio determination of edge surface structures for dioctahedral 2 1 phyllosilicates implications for acid-base reactivity. Clays Clay Miner. 51, 359-371. 

Good laboratory safety practice requires that incompatible chemicals be stored, transported, and disposed of in ways that will prevent their coming together in the event of an accident. Tables 1 and 2 give some basic guidelines for the safe handling of acids, bases, reactive metals, and other chemicals. Neither of these tables is exhaustive, and additional information on incompatible chemicals can be found in the following references. 

The synthesis and characterization of hydride and dihydrogen complexes with the widest range possible of acid-base reactivity... 

THE SYNTHESIS AND CHARACTERIZATION OF HYDRIDE AND DIHYDROGEN COMPLEXES WITH THE WIDEST RANGE POSSIBLE OF ACID-BASE REACTIVITY... 

Figure 1.3 Classification of organocatalysts according to their acid/base reactivity.

Acid-Base Reactivity in Supercritical Deuteroxide Solution, Journal of the American Chemical Society 116, 11229-11233... 

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