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7. Fundamental Principles of Organic Chemistry eLearn.Punjab

7.8 FUNCTIONAL GROUP

An atom or a group of atoms or a double bond or a triple bond whose
presence imparts specific properties to organic compounds is called a
functional group, because they are the chemically functional parts
of molecules.

The study of organic chemistry is organized around functional groups.
Each functional group defines an organic family. Although over six mil-
lion organic compounds are known, there are only a handful of func-
tional groups, and each one serves to define a family of organic com-
pounds. The examples of functional groups are outlined in Table 7.2.

TABLE 7.2 FUNCTIONAL GROUPS

Functional group Class of compounds Example

Formula Name

CC None Alkane CH — CH3

CC Double bond Alkene H2C = CH2
CC Alkyne HC=CH
-X(X=F,Cl,Br,I) Triple bond Alkyl halide
OH Halo (fluoro, chloro, CH3-CH2-Cl
NH2 Alcohol or alkanol CH3-CH2-OH
C NH bromo, iodo) Amine CH3-CH2-NH2
Hydroxyl group Imine
CH2=NH
Amino group

Imino group

CO C Ether linkage Ether CH3-CH2-O-CH2-CH3
Formyl group Aldehyde or alkanal
O Ketone or alkanohe O
C Carbonyl
CH3-C
H H

R O CH3 O
C C

R CH3

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