Spin system

Spin system :-
                         The spin system is used to describe a gourp of proton only which each other only the spin system may be complete molecule and a part of molecule.
Nation of a spin system :- 
                                               The proton which have smaller chemical system is denoted by A,B,C in order of shielding.
The proton which have intermediate chemical shift difference is denoted by intermediate  (A,B, C ).
The large chemical shift difference is denoted by X, Y, Z.
The number of proton is denoted in subscript (A) the proton whose s- value  near to NMR given A  , B ,C.
Type of spin system :-
     1.AB spin system :-
                                      In AB spin system there are two proton which interact with each other only.
The chemical shift difference for AB spin system is small as campare to coupling constant.

The line found near to each other if the chemical shift difference decrease then inner peak large and outer peak become small then NMR peak.
2. AX system :-
                          In AX system there are two proton with couple with each other only.
The chemical shift difference between for AX system is very large as campare to coupling constant.

In AX system we get two double of equal intensity the peak are very well separated.
3.AMX system :- 
                              In a AMX spin system there proton are couple with each other only.
The chemical shift difference between proton are intermediate for A proton and X proton it quite large
We get three shift in NMR system of AMX system.

We get three doublet in NMR spectroscopy of AMX spin system , the formation of these line can be explain as following
The intermediate of NMR spectra indicate that when x-proton couple with A type of proton
4.ABX spin system :-
                                 In ABX system three proton couple with is each other but not any other proton of the system .
The chemical shift between two proton is very small approach and third proton X the chemical is very large.
Example-

In NMR of ABX system we observe three doublet or 12 lines due to the splitting by arrises by spin- spin coupling.
In ABX system we study the NMR in two parts-
1. The amount portion of AB spectra contain total at lines but small chemical shift difference some of the peak overlap to each other and number of lines decrease.
2. The X portion of spectra contain for lines of equal intensity .