Functional group

In the chemical is meant functional groups ( also characteristic groups ) groups of atoms in organic compounds, which determine the material characteristics and the reactivity of the compounds carrying them significantly. Chemical compounds that have the same functional groups are summarized on the basis of their often characteristic of substance classes.

Functional groups (e.g., ether) and those without heteroatoms ( for example, C = C double bonds, C ≡ C- triple bonds or aromatic ) divided on the basis of the participating atoms in functional groups containing hetero atoms. The latter are sometimes not considered functional groups as " full ", because they are considered first, only as a structural building blocks that are not reactive little to the other to.

In the case of inorganic or organometallic compounds, simple alkyl or aryl groups to be regarded as functional groups. All organic side chains and functional groups are then grouped under the general designation Organylgruppe.

Often, for these groups to simplify case introduced in the structural formulas, and text abbreviations are listed in the list of abbreviations in the organic chemistry.

Properties

As the definition suggests a functional group influences the chemical and physical properties of the starting compound containing them often considerably. The nature of the influence of the functional groups is shown here for the alkane n -butane and three of its derivatives:

Different functional groups and their Nomenclature

Basically, the substitutive nomenclature, described below, to use for naming substances. According to this nomenclature the functional group either as a prefix (prefix ) or as a suffix (suffix) is contained in the name of the whole compound.

See also: Nomenclature

Functional groups ( in order of decreasing priority order)

For the names of these groups in a compound either prefixes or suffixes are used. The highest ranking group is used here as an ending, and all others in alphabetical order, as prefixes. The various classes of compounds are ordered in the following table in order of decreasing priority.

In part, there different names, depending on whether the specified carbon atom form a part of the root system (see keyword nomenclature ) is (illustration: R CXYZ ) or not ( representation: R- CXYZ ). As usual in the chemical industry, the letter R is an organic radical is the placeholder X stands for halide.

Functional groups without priority

Basically only as prefixes ( prefixes ) uses the following functional groups:

Special case of multiple bonds

Also included among the functional groups, the multiple bonds:

From the perspective of nomenclature multiple bonds but are generally regarded as part of the root system.

Alternative nomenclature systems

In addition to this nomenclature system, there are other, less common or obsolete nomenclature systems. One of these is, for example, the radikofunktionelle nomenclature, be called after eg chloromethane as methylene chloride or ethanol as ethyl alcohol.