begin mathsize 36px style D B E space equals space C plus 1 minus H over 2 minus X over 2 plus N over 2 end style 

C= Number of Carbon atoms present ; H = Number of Hydrogen atoms present; X= Number of Halogen atoms present (Cl, Br, I or F);
N= Number of Nitrogen atoms present; DBE = Double bond equivalent a.k.a Level of Unsaturation

Write the formula of an Organic Compound by changing the coefficients below 

C H N O X

 
DBE or double bond equivalent a.k.a LU or level of unsaturation is the number of unsaturations present in a organic molecule. The term unsaturation mean a double bond or a ring system. For instance , in benzene there are 3 double bonds and 1 ring which gives us 4 DBE. Moreover a tripple bond can be regarded as DBE=2. It must be noted that X is the total number of halogens, namely Cl, Br, F and I present in the structure. Presence of an oxygen atom does not effect the DBE calculation.       

Generate Citation