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Über dieses Buch

This brief introduces readers to an alternative thermochemical reference system that makes it possible to use the heats of formation of organic compounds to deduce the energies that depend entirely on their structures, and which provides calculated values for most of the characteristic structures appearing in organic molecules. These structure-dependent energies are provided e.g. for selected compounds of normal and cyclic alkanes, open chain and cyclic olefins (including conjugated polyenes), alkynes, aromatic hydrocarbons and their substituted derivatives. The oxygen, sulfur and nitrogen derivatives of the above-mentioned compounds are also represented with calculated structure-dependent energies including alcohols, ethers, aldehydes and ketones, carboxylic acids, thiols, sulfides, amines, amides, heterocyclic compounds and others. Most organic reactions can be interpreted as the disappearance of certain structures and formation of others. If the structure-dependent energies are known, it can be shown how the disappearing and the newly formed structures contribute to the heat of reactions and to the driving forces. As experienced by the author, who pioneered the concept, structure dependent energies can help teachers to make organic chemistry more accessible for their students. Accordingly, the brief offers a valuable resource for all those who teach organic chemistry at universities, and for those who are learning it.

Inhaltsverzeichnis

Frontmatter

Chapter 1. An Alternative Thermochemical Reference System

Abstract
The chemical compounds have energies that depend on their composition and structure. The absolute values of these energies are not known. The quantities that can be really measured are the heats of their reactions.
Árpád Furka

Chapter 2. Hydrocarbons

Abstract
The relative enthalpies of the gas state n-alkanes are listed in Table 1.3. Their values except that of methane are practically zero. It is long known from comparisons of the heats of formation of isomeric alkanes that branching mostly causes stabilization. This is supported by the relative enthalpies of Table 1.4.
Árpád Furka

Chapter 3. The Oxygen Derivatives of Hydrocarbons

Abstract
Oxygen is a high energy element. This is shown by its high \( H_{rel}^{o} \) (125.83 kJ/mol). When it forms compounds a considerable amount of energy is evolved.
Árpád Furka

Chapter 4. Organonitrogen Compounds

Abstract
Triethylamine is the reference substance for nitrogen compounds so the \( H_{rel}^{o} \) of it is assigned to be zero.
Árpád Furka

Chapter 5. Organosulfur Compounds

Abstract
Sulfur differs from oxygen since it is a low energy element.
Árpád Furka

Chapter 6. Organohalides

Abstract
As reflected by their relative enthalpies, the four halogens occurring in organic compounds have different energies in their elemental form.
Árpád Furka

Chapter 7. Radicals, Cations, and Anions

Abstract
Like in the case of compounds, the relative enthalpies of radicals, cations and anions calculated from their heats of formation can be used to characterize their energy.
Árpád Furka

Chapter 8. Inorganic Compounds

Abstract
In the traditional thermochemical reference system zero values are assigned to the heats of formation of the elements. Although the zero values were logical choices that work properly in practice, they tell absolutely nothing about the nature of the elements.
Árpád Furka

Chapter 9. Components of the Heats of Reactions

Abstract
In organic chemistry text books the feasibility of organic reactions is most often interpreted by the reactivity of the reactants. Basicity, acidity, nucleophylicity or electrophilicity are important factors that are considered. While the importance of the reactivity can’t be questioned, reactivity is not the only determining factor in the reactions. There are other important factors as energy and entropy.
Árpád Furka
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