index of unsaturation

index of unsaturation

[′in‚deks əv ¦ən‚sach·ə′ra·shən]
(organic chemistry)
A numerical value that represents the number of rings or double bonds in a molecule; a triple bond is considered to have the numerical value of 2.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.