GROUND RULES FOR SIMPLE SPLITTING PATTERNS

 

(1) SPLITTING IS USUALLY OBSERVED BETWEEN NONEQUIVALENT H'S THAT ARE WITHIN A FEW BONDS FROM ONE ANOTHER.

 

(2) A SET OF n NEIGHBORING H'S WILL SPLIT A PROTON'S SIGNAL INTO A MULTIPLET HAVING n+1 PEAKS.

 

(3) THE PEAKS IN A MULTIPLET WILL HAVE RELATIVE INTENSITIES GIVEN BY PASCAL'S TRIANGLE:

 

1 - SINGLET

1 1 - DOUBLET

1 2 1 - TRIPLET

1 3 3 1 - QUARTET

1 4 6 4 1 - QUINTET

1 5 10 10 5 1 - SEXTET

 

CAVEAT: FOR THE n+1 RULE TO APPLY, THE CHEMICAL SHIFT DIFFERENCE BETWEEN THE H'S SPLITTING ONE ANOTHER MUST BE ABOUT .5 PPM OR MORE, OR ELSE THE MULTIPLETS BECOME DISTORTED AND/OR DIFFERENT RULES APPLY. ALSO, THE COUPLING CONSTANT OF ALL NEIGHBORING H'S MUST HAVE ABOUT THE SAME VALUE.