Functional Groups- Definition, Types, Structure, Examples

The functional groups are the reactive group present in compounds that determine the chemical properties of these compounds. Eg: -OH, -F, -CHO, -COOH.

Types of Functional Groups

Hydrocarbons

This includes alkane, alkene, alkyne, and benzene derivatives. They are typically denoted by the symbol -R. Hydrocarbons are made up of carbon and hydrogen that are linked together by various types of bonds, such as single, double, and triple bonds that determine their reactivity. E.g., alkane, alkene, alkyne.

Haloalkanes

Haloalkanes are alkyl halides that consist of a carbon-halogen bond. The strength and stability of the carbon-halogen bond determine the reactivity of these compounds. E.g., chloroalkane, bromoalkane, iodoalkane

Nitrogen containing functional group

These are the functional groups containing carbon-nitrogen bonds. They typically contain amines and amides. E.g., amides, amines, imines, azo compounds

Oxygen containing functional groups

They consist of the carbon-oxygen bond. The properties of compounds containing carbon-oxygen bonds are determined by the hybridization of the carbon-oxygen bond. E.g., alcohols, ketones, aldehydes, peroxides.

Sulphur containing functional groups

This type of functional group consists of the carbon-oxygen bond. Sulfur-containing compounds have distinct chemistry due to their ability to form more bonds than oxygen. E.g., thiols, thials, disulfur.

Phosphorous containing functional groups

Phosphorus-containing compounds have distinct chemistry due to their ability to form more bonds than nitrogen. Many phosphorous-containing functional groups consist of carbon-phosphorous and phosphorous-oxygen bonds. Phosphate diphosphate and triphosphate groups are linked to carbon via phosphate ester linkages in a variety of organic compounds. E.g., phosphine, phosphate group.

List of 35 different functional groups

S.N.	Functional group	Structure	Prefix	Suffix	Examples
1.	Carboxylic group		carboxy	-oic acid	Ethanoic acid(CH3COOH)
2.	Acid Anhydride		—	-oic anhydride	Ethanoic anhydride (CH3COOCOCH3)
3.	Carboxylic ester		alkoxycarbonyl	-carboxylate	Methylethanoate (CH3COOCH3)
4.	Amide		amide	-carbomyl	Ethanamide (CH3CONH2)
5.	Nitrile		cyano	-nitrile	Ethane nitrile(CH3CN)
6.	Aldehyde		oxo or formyl	-al, -carbaldehyde	Propanal (C2H5CHO)
7.	Ketone		oxo	-one	Propanone (CH3COCH3)
8.	Alcohol		hydroxy	-ol	Butanol (C4H9OH)
9.	Amine		amino	-amine	Methyl amine (CH3NH2)
10.	Alkene		enyl	-ene	Propene(C3H6)
11.	Alkyne		ynyl	-yne	Propyne (C3H4)
12.	Alkyl		yl	-ane	Ethane (C2H6)
13.	Alkyl halide		halo(fluro, chloro, bromo, iodo)	– alkyl halide	Chloropropane(C3H7Cl)
14.	Ether		oxy	ether	Dimethyl ether (CH3OCH3)
15.	Sulphide		alkylthio	sulfide	Dimethyl sulfide (CH3SCH3)
16.	Nitro		nitro	–	Nitromethane (CH3NO2)
17.	Benzene		phenyl	benzene	Ethylbenzene (C6H5C2H5)
18.	Disulphide		substituent disalfanyl	-disulfide	Dimethyl disulfide (CH3-S-S-CH3)
19.	Thiol		mercapto	-thiol	Propane-1-thiol (C3H7SH)
20.	Isocyano		isocyano	isonitrile	Methyl isonitrile (CH3NC)
21.	Cyanate		cyanate	–	
22.	Isocyanate		isocyante	–	Methyl isocyanate (CH3NCO)
23.	Peroxide		(R)-peroxy	peroxide	Dimethyl peroxide(C2H6O2)
24.	Hydroperoxy		hydroperoxy	hydroperoxide	Methyl peroxide (CH4O2)
25.	Alcoholates, Phenolates		oxido		Glyoxylic acid methyl ester methyl alcoholate (C4H7O4–)
26.	Sulphonates		sulfonato	-sulfonate	Naphthalene-1-sulphonate (C10H7O3S)
27.	Sulfonic acid		sulfo	-sulfonic acid	Benzene sulfonic acid (C6H6O3S)
28.	epoxide		epoxy	-ene oxide	Propylene oxide (C3H6O)
29.	azo		azo	–	Azobenzene (C12H10O2)
30.	Sulfoxide		sulfinyl	-sulphoxide	Dimethyl sulphoxide (CH3SOCH3)
31.	Sulfone		sulfonyl	-sulfone	Dimethyl sulfone (CH3SO2CH3)
32.	Sulfinic acid		sulfino	-sulfinic acid	Propanesulfinic acid (C3H7SO2H)
33.	Thial		thial		Methanethial (CH3SH)
34.	Thiocyante		thiocyanate		Ethyl thiocyanate (C2H5-S-CN)
35.	phosphine		phosphanyl	-phosphane	(C3H7-PH2)

References

1. https://chem.libretexts.org/Courses/Sacramento_City_College/SCC%3A_CHEM_330_-Adventures_in_Chemistry(Alviar-Agnew)/09%3A_Organic_Chemistry/9.09%3A_Nitrogen-Containing_Compounds-_Amines_and_Amides
2. https://www.britannica.com/science/functional-group
3. https://kpu.pressbooks.pub/organicchemistry/chapter/2-4-naming-of-organic-compounds-with-functional-groups/
4. https://en.wikipedia.org/wiki/Functional_group
5. https://byjus.com/chemistry/functional-groups/
6. https://www.vedantu.com/chemistry/nomenclature-functional-groups
7. https://www.compoundchem.com/2020/02/21/functional-groups/