In this article we want to discuss things related chain isomer example with detailed facts as well.
Isomers are those compounds which have same molecular formula but arrangement of atoms is different in space. There are various types of isomer exist in chemistry out of those chain isomer is an important one. There are some compounds which have same molecular formula but arrangement of carbon atoms are different in chains defined as chain isomers.
Chain isomers example are given below:
n-butane
n-butane has molecular formula C4H10. It’s 2 chain isomers examples are one is n-butane which is a straight chain compound and the other one is 2-Methyl Propane which is branched chain compound. In n-butane there are 4 C atoms which are arranged in a straight chain and each C atom is sp3 hybridized.
In 2-Methyl Propane there are also 4 C atoms out of which 3 are in single straight chain and 1 is in branched form. Here also all the C atoms are sp3 hybridized. In n-butane there are 2 -Ch2 groups which are 20 i.e. attached with 2 C atom and 2 -Ch3 groups which are 10 i.e. attached with 1 C atom.
Both chain isomers have same molecular formula but arrangement of C atoms are different in 2 structure. But these two isomers have different physical and chemical property. As for example n-butane has more van der waals force of attraction than 2- Methyl Propane. For this reason n-butane has more boiling point than 2-Methyl Propane.
n-pentane
n-pentane has molecular formula C5H12. It exist in 3 chain isomers. It’s chain isomers example are n-pentane, 2-Methylbutane, 2,2-Dimethylpropane. Out of these 3 only n-pentane is straight chain isomer and the remaining 2 are branched chain compound. in n-pentane there are 5 C atoms which are arranged in straight chain and each C atom is sp3 hybridized.
In these compound there are 3 –Ch2 groups out of these 2(attached with 2 C atoms) are 20 and 1 is primary(attached with 1 C atom). There are also 2 methyl groups which are 10( attached with only 1 C atom). All the 3 chain isomers have same molecular formula but C atom’s distribution is different.
But these 3 chain isomers examples have different chemical and physical property. Boiling point order of these 3 isomers is given below: n-pentane>2-methylbutane>2,2-dimethyl propane. This is because n-pentane has highest and 2,2-dimethylpropane has least van der waals force of attraction.
n-hexane
n-hexane has molecular formula C6H14. It has 5 chain isomers example. These are n-hexane, 2-methyl pentane, 3-methyl pentane, 2,3-dimethyl butane, 2,2- dimethyl butane. Out of these only n-hexane is straight chain isomer and the remaining ones are branched chain isomer.
In n-hexane there are 6 C atoms which are arranged in straight chain and each C atom is sp3 hybridized. In this compound there are 5 Ch2 groups and 2 Ch3 groups. In 2-methyl pentane there are 2 Ch2 group and 2 Ch3 group and also 1 Ch group with which 1 Ch3 group (at 2 position) is attached.
In 3-methyl pentane arrangement of groups i.e. (Ch,Ch2,Ch3) are same but in this compound Ch3 group attached with Ch group at 3 position. In 2,3-dimethyl butane there are total 4 Ch3 groups attached with 2 Ch group symmetrically.
In 2,2-dimethyl butane 3 Ch3 groups attached with 1 C and 1 Ch3 group is attached with Ch2 group. All 5 chain isomer have same molecular formula but distribution of atoms is different.
Boiling point order of these isomer are given below: n-hexane>3-methyl pentane>2-methyl pentane>2,3-dimethyl butane>2,2- dimethyl butane. This is due to the fact that n-hexane has highest VDW and 2,2-dimethyl butane has least Van Der waals force of attraction.
n-heptane
n-heptane has molecular formula C7H16. It has 7 chain isomers example. These are n-heptane, 2,3-dimethyl pentane, 3,3-dimethyl pentane, 2-methyl hexane, 2,4-dimethyl butane, 3-ethyl pentane, 3-methyl hexane, 2,2-dimethyl pentane, 2,2,3-trimethyl butane.
Out of these only n-heptane is straight chain isomer but the remaining ones are branched chain isomers. In n-heptane there are 5 Ch2 groups and 2 Ch3 groups. In 2,3-dimethyl pentane there are 1 Ch2 group, 2 Ch3 group and2 Ch group with which 2 Ch3 group is attached. In 3,3-dimethyl pentane there are 2 Ch2 group , 2 Ch3 group and 1 C atom with which 2 Ch3 group is attached.
In 2-methyl hexane there are 3 Ch2 group, 2 Ch3 group and 1 Ch group with which 1 Ch3 group is attached. In 2,4-dimethyl pentane there are 1 Ch2 group, 2 Ch3 group and 2 Ch group with which 2 Ch3 group is attached. In 3-ethyl pentane there are 2 Ch2 group, 2 Ch3 group and 1 Ch group with which 1 Ethyl group is attached.
In 3-methyl hexane there are 3 Ch2 group, 2 Ch3 group and 1 Ch group with which 1 Ch3 group is attached. In 2,2-dimethyl pentane there are 2 Ch2 group,2 Ch3 group and 1 C atom with which 2 Ch3 groups are attached. In 2,2,3-trimethyl butane there are 2 Ch3 group, 1 Ch group with which 1 Ch3 is attached and 1 C atom with which 2 Methyl group is attached.
All these 9 isomer have same molecular formula but distribution of C and H atoms are different in chains in these isomers. Out of the 9 chain isomer n-heptane has highest boiling point and 2,2,3-trimethyl butane has least boiling point. This is due to the fact that n- heptane has highest VDW and 2,2,3-trimethyl butane has least Van der waals force of attraction.
n-butyl amine
n-butyl amine has molecular formula C4H11N. It has 4 chain isomers example. These are n-butyl amine, 1-methyl propyl amine, isobutyl amine, tert-butyl amine. Out of these only n-butyl amine has chain structure and the remaining 3 have branched structure.
In n-butyl amine there are 3 Ch2 group,1 methyl group and 1 Nh2 group which is 10 is nature. In 1-methyl propyl amine there are 1 Ch2 group,1 methyl group and 1 Ch group with which 1 Ch3 as well as 1 Nh2 is attached. In isobutyl amine there are 1 Ch2 group with which 1 Nh2 group is attached .
There also 1 Ch group with which 2 methyl group is attached. In tert butyl amine there is 1 C atom with which 3 Ch3 group and 1 Nh2 group is attached. Out of these 4 chain isomer of amine n-butyl amine (highest VWD forces) has highest boiling point and tert-butyl amine has least boiling point(least van der waals forces).
n-propyl amine
It is the simplest chain isomer of monomeric amines. It has the formula C3H9N. It has 2 chain isomers example. These are n-propyl amine and 2-methyl Ethan amine. N-propyl amine has straight chain structure while 2-methyl amine has branched chain structure.
In the 1st one there are 2 Ch2 group,1 Ch3 group and 1 Nh2 group. In the 2nd one there are 1 Ch group with which 2 methyl group and 1 Nh2 group is attached.
As expected straight chain isomer i.e. n-propyl amine has highest boiling point and 2-methyl amine has least boiling point. This is because n-propyl amine has higher van der waals force of attraction than 2-methyl ethan amine.
Hi….I am Susanta Maity. I have completed my Masters from Vidyasagar university with a specialization in organic chemistry.
I love to write complicated Chemistry concepts in understandable and simple words.
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