Elements of Unsaturation CH, CH,一CH2一CH CH3一CH=CH CH2-CH, CH,一C=C-H propane,C.H propene,C,H。 cyclopropane,C,H propyne,C.H saturated one element of unsaturation one element of unsaturation two elements of unsaturation 2013 Pearson Education.inc Unsaturation:Structural element that decreases number of hydrogens in the molecule by 2. Also called index of hydrogen deficiency. Double bonds and rings are elements of unsaturation. Triples bonds also elements of unsaturation (like having 2 double bonds). 2013 Pearson Education Inc.Elements of Unsaturation • Unsaturation: Structural element that decreases number of hydrogens in the molecule by 2. • Also called index of hydrogen deficiency. • Double bonds and rings are elements of unsaturation. • Triples bonds also elements of unsaturation (like having 2 double bonds). 7 © 2013 Pearson Education Inc