Conformations of Alkanes Title

Eclipsed C-H/C-H interaction = 1.0 kcal/mol Ethane

Eclipsed CH 3 /H interaction = 1.3 kcal/mol Propane

, anti Eclipsed CH 3 /CH 3 interaction = 3.3 kcal/mol 0.9 Gauche CH 3 /CH 3 interaction = 0.9 kcal/mol Butane

2- Methylbuta ne Highest energy eclipsed conformations Lowest energy staggered conformations Conformation of 2-Methylbutane

EtPrBuIsobutG raph Conformational Energy of C 2 - C 5 Acyclic Alkanes Energy (kcal/mol) Dihedral Angle Methylbutane

Cyclohexane chair 10 half chair 10 half chair o K eq = e -  E/RT K eq = ~ twist boat 5.5 twist boat 6.9 boat

The End Title F. E. Ziegler 2009