Carboxylic Acids addresses
the usual topics covered in the introduction of a new family: structure,
common and formal nomenclature, physical properties, preparations,
reactions, chemical and spectroscopic analysis. Characteristics
and nomenclature of salts is included.
Nomenclature of carboxylic acids is not complete without some mention
of the origin of some of the names. In addition to naming the acids,
both by common and systematic methods (IUPAC), the essential fatty
acids are denoted and the meaning of the term. The nomenclature
of unsaturated fatty acids is also addressed, as are the diacids.
It is noted in the section on physical properties that the carboxylic
acids are infinitely soluble in water through four carbons. The
solubilities of other acids, including aromatic acids, are also
addressed. The tendency of acids to form dimers, a factor which
contributes to their high boiling points is explained. The impact
of other groups present, such as halogens, and the impact of those
groups on the acidity of carboxylic acids is addressed and these
properties compared. Dissolving of carboxylic acids having more
than ten carbons can be problematic unless the acid can be converted
to the corresponding salt. The unit addresses this and the subsequent
regeneration of the acid when desired.
Throughout this section, the equilibrium existing in aqueous solutions is reviewed
and problems addressed. Hydrolysis of salts and the pH generated
from these aqueous solutions is also addressed. The section on salts
is expanded to include naming of the salts and the formation of
soaps. The characteristics and action of soap is discussed, as is
the action of soap in hard water.
Preparation of acids includes several oxidation reactions, oxidation
of alcohols, arenes, alkenes and alkynes. The use of the grignard
with carbon dioxide is included as is the hydrolysis of nitriles.
Salt formation is an important aspect of carboxylic acid chemistry,
and it is summarized in a reactions section. The section covering
the several products that may result from reduction of acids particularly
addresses the use of lithium aluminum hydride and its limitations,
as well as diborane in diglyme. In addition to the usual decarboxylation
reaction using heat, the Hunsdiecker reaction with heavy metal ions
is addressed. The synthesis pathways opened up by the Hell-Volhard-Zelinski
reaction are presented. Whenever it is beneficial to understanding,
animations of reactions are used.
Test tube analysis reviews some of the reactions of carboxylic acids
that produce color changes, precipitates, or gases; such as the
reactions with bicarbonate and bromine with silver oxide. Infrared
analysis of carboxylic acids gives some characteristic signals that
are addressed. Proton NMR absorption so far downfield that it may
not even show on a simple instrument concludes this section.