Quiz 5 Flashcards
Lectures 12-14
two different compounds with the same molecular formula; differ in the ay the atoms are connected to each other (example: butane and isobutane)
Constitutional Isomers (structural isomers)
different arrangements of atoms that are interconverted by rotation about single bonds
conformations
When C-H bonds on one carbon are directly aligned with C-H bonds on the adjacent carbon. The dihedral angle is 0 degrees
eclipsed conformation
When the C-H bonds on one carbon bisect the H-C-H bond angle on the adjacent carbon
staggered conformation
The energy difference between staggered and eclipsed conformers is called:
torsional energy
An increase in energy caused by eclipsing interactions
torsional strain
A staggered conformation with two larger groups 180 degrees from each other
anti
A staggered conformation with two larger groups 60 degrees from each other
gauche
increase in energy resulting when nonbonded atoms are forced too close to one another (gauche conformations)
steric strain
energy difference between the lowest and highest energy conformations
barrier to rotation
an increase in energy when bond angles deviate from the optimum tetrahedral angle of 109.5
angle strain
hydrogens located in the plane of the ring (around the equator)
equatorial hydrogens
hydrogens located above and below the ring
axial hydrogens
This conformation of a cyclohexane is destabilized by torsional strain and steric strain
boat conformation
An isomer that has two groups on the same side
cis isomer
