PLEASE explain what is neo,tert,sym,iso,n,sec, etc in nomenclaturenpart in complete details

n, sec, iso, tert, neo are the prefixes that are used to describe the structure of an organic compound. These are used in the common names of organic compounds. 

1) The prefix 'n' is used in those cases where the organic is a straight chain compound and has no branching. For example 

CH3CH2CH2CH2Br will be named as n−Butyl bromide as this compound has 4 carbon atoms, halogen functional group and the alkyl group is simple straight chain that has no branching. 

2) The prefix 'iso' is used when the alkyl groups of organic compounds have 6 or less carbon atoms, and one carbon branch is present on the second last carbon atom of the chain. For example in the following compound 

 

the alkyl group has a methyl branch present on the second last carbon atom. Hence its name is Isobutyl chloride.

3) The prefix 'sec' is used when a functional group, is attached to a secondary carbon atom ( a carbon atom attached to 2 carbon atoms). Example in the following compound 

   

the functional group, Br is attached to a secondary carbon atom

4)  The prefix 'ter' is used when a functional group, is attached to a tertiary carbon atom- a carbon atom attached to three carbon atoms. For example the compound (CH3)3CBr will be called tert-Butyl bromide, as the functional group Br is attached to tertiary carbon atom.

5)  The prefix 'neo' is used when the organic compound has a structure similar to neopentane, a 5 carbon compound in which the second carbon atom has two attached carbon atoms. Its structure is as follows

                                         

Following is neo-Pentyl bromide

 (CH3)3CCH2Br

Please note that sym stands for symmetric and is not very often used in nomenclature

 

  • 200
What are you looking for?