An alkyl is a univalent radical consisting of carbon and hydrogen atoms, arranged in a chain. In Chemistry, valence, also known as valency or valency number, is a measure of the number of Chemical bonds formed by the Atoms In Chemistry, radicals (often referred to as free radicals) are atoms molecules or ions with Unpaired electrons on an otherwise Open shell Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 The alkyls form a homologous series with the general formula C_nH_2n+1. In Chemistry, a homologous series is a series of Organic compounds with a similar General formula, possessing similar chemical properties due to the presence They include methyl, CH₃· (named after methane), ethyl (C₂H₅·), propyl (C₃H₇·), butyl (C₄H₉·), pentyl (C₅H₁₁·), and so on. Methane is a Chemical compound with the molecular formula. It is the simplest Alkane, and the principal component of Natural gas. They are usually constituents of larger molecules, but when occurring independently, they are known as "free radicals" and are very reactive. In Chemistry, radicals (often referred to as free radicals) are atoms molecules or ions with Unpaired electrons on an otherwise Open shell

The structure of an alkyl is like that of its alkane counterpart, but with one less hydrogen atom. Alkanes, also known as Paraffins are Chemical compounds that consist only of the elements Carbon (C and Hydrogen (H (i For example, this is the structure of methyl, the smallest alkyl:

A secondary alkyl group is branched with the central carbon atom linked to two carbon residues. Likewise, in tertiary alkyl groups, there are three carbon-linked substituents. In neopentane, the central carbon atom is quaternary. Neopentane, also called dimethylpropane or 22-dimethylpropane, is a double-branched-chain Alkane with five Carbon atoms

Contents 1 Reactions 2 Naming Alkyls 2.1 Branched chained structures 3 See also

Reactions

Unbonded alkyls are free radicals, therefore they are formed only as instantaneous intermediates in reactions usually involving other free radicals. In Chemistry, radicals (often referred to as free radicals) are atoms molecules or ions with Unpaired electrons on an otherwise Open shell When a free radical is formed it very quickly reacts with something else to lose the unpaired electron.

An example of a reaction where alkyls are formed instantly is chlorination. This reaction involves chlorine free radicals, formed by photodissociation, reacting with an organic molecule, usually an alkane. Photodissociation, photolysis, or photodecomposition is a Chemical reaction in which a Chemical compound is broken down by Photons The chlorine free radical will bond with a hydrogen from an alkane forming hydrochloric acid and leaving an alkyl. This alkyl will then bond to a chlorine to form the product; a chloroalkane. The reaction is very energetic and can be explosive if proper precautions are not taken. This is because of the reactivity of free radicals.

Alkyls are very commonly observed in mass spectroscopy of organic compounds. Mass spectrometry is an analytical technique that identifies the chemical composition of a compound or sample based on the Mass-to-charge ratio of charged particles An organic compound is any member of a large class of Chemical compounds whose Molecules contain Carbon.

Naming Alkyls

The naming convention for alkyls is much the same as alkanes. Alkanes, also known as Paraffins are Chemical compounds that consist only of the elements Carbon (C and Hydrogen (H (i The suffix is always -yl. The prefix depends on how many carbon atoms are in the molecule. This uses the same system as for alkanes as shown in this table (taken from IUPAC nomenclature):

Number of carbons	1	2	3	4	5	6	7	8	9	10	11	12
Prefix	meth-	eth-	prop-	but-	pent-	hex-	hept-	oct-	non-	dec-	undec-	dodec-
Molecule name	Methyl	Ethyl	Propyl	Butyl	Pentyl	Hexyl	Heptyl	Octyl	Nonyl	Decyl	Undecyl	Dodecyl

Branched chained structures

These names are used to name branched chained structures, for example 3-methylpentane:

The structure of 3-methylpentane consist of two parts. IUPAC Nomenclature is a system of naming Chemical compounds and of describing the science of Chemistry in general In Chemistry, a methyl group is a Hydrophobic Alkyl Functional group named after Methane (4 In Organic chemistry, propyl is a three- Carbon Alkyl substituent with Chemical formula - C 3 H 7 In Organic chemistry, butyl is a four- Carbon Alkyl substituent with Chemical formula -C4H9. In Organic chemistry, pentyl is a five- Carbon Alkyl substituent with Chemical formula -C5H11. Firstly, the longest straight chain of carbon atoms, 5 carbons long with all single bonds, which is named pentane (highlighted blue). Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 Secondly, there is an alkyl group, which is one carbon long, which is methyl (highlighted red). Alkyl groups are included in the name of the molecule before the root, as in methylpentane. This name is, however, ambiguous, as the methyl branch could be on various carbon atoms. Thus, the name is 3-methylpentane to avoid ambiguity: the 3- is because the methyl is attached to the third of the 5 carbon atoms.

If there is more than one of the same alkyl group attached to a chain, then the prefixes are used on the alkyl groups to indicate multiples (i. e. di, tri, tetra, etc. )

This compound is known as 2,3,3-trimethylpentane. Here there are three identical alkyl groups attached to carbon atoms 2, 3 and 3. These numbers are included in the name to avoid ambiguity on the position of the groups and 'tri' indicates that there are three identical methyl groups. If one of the methyl attached to the third carbon atom was an ethyl group, then the name would become 3-ethyl-2,3-dimethylpentane. Note that when there are different alkyl groups, they are listed in alphabetical order.

See also

• Alkane
• Aryl
• IUPAC nomenclature of organic chemistry

Alkanes, also known as Paraffins are Chemical compounds that consist only of the elements Carbon (C and Hydrogen (H (i In the context of organic molecules aryl refers to any Functional group or Substituent derived from a Simple aromatic ring, may it be Phenyl The IUPAC nomenclature of organic chemistry is a systematic method of naming organic chemical compounds as recommended by the International Union of Pure and Applied

© 2009 citizendia.org; parts available under the terms of GNU Free Documentation License, from http://en.wikipedia.org
Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic