(TYPE 2): GIVEN A MOLECULAR FORMULA (M. F.) AND A SPECTRUM, DRAW A STRUCTURE CONSISTENT WITH THE DATA.

 

(1) USE THE M. F. TO DETERMINE THE INDEX OF HYDROGEN DEFICIENCY (IHD AKA SODAR AKA # OF POINTS OF UNSATURATION). THIS GIVES THE TOTAL OF DOUBLE AND TRIPLE BONDS AND RINGS.

 

(2) DETERMINE THE # OF SIGNALS IN THE SPECTRUM EXCLUDING MULTIPLICITY. THIS GIVES THE MAXIMUM # OF SETS OF EQUIVALENT H'S (# OF DIFFERENT KINDS OF H'S). FOR SIMPLE MOLECULES IT EQUALS THE # OF SETS OF EQUIVALENT H'S.

 

(3) THE INTEGRATION GIVES THE # OF H'S IN EACH SET.

 

(4) EXAMINE CHEMICAL SHIFTS TO GET FUNCTIONAL GROUP (FG) INFO. KNOWING THE ELEMENTS PRESENT AND THE IHD FROM THE M. F. MAY ALLOW A PRECISE DETERMINATION OF WHICH FG'S ARE PRESENT.

 

(5) GROUP EACH SIGNAL WITH OTHER SIGNALS AS WELL AS POSSIBLE BASED ON THE MULTIPLICITIES OF THE SIGNALS.

 

(6) DRAW AS MUCH OF THE MOLECULE AS YOU CAN THAT IS CONSISTENT WITH THE INFO KNOWN SO FAR. YOU MAY ONLY BE ABLE TO DRAW SMALLER FRAGMENTS OF THE MOLECULE AT THIS POINT. FROM THE FRAGMENT(S) THAT YOU'VE DRAWN AND FROM THE M. F., FIND OUT WHAT REMAINING ATOMS NEED TO BE ACCOUNTED FOR.

 

(7) REITERATE STEPS 1 - 6, EACH TIME TRYING TO PIECE MORE AND MORE OF THE MOLECULE TOGETHER.

 

(8) WHEN A FINAL STRUCTURE IS PROPOSED, GO THROUGH THE STEPS IN THE TYPE 1 PROBLEM TO CONFIRM YOUR STRUCTURE.