Test #2 Terms Flashcards
Staggered Configuration
Most stable but lowest energy, 60 or 180 degrees
Eclipsed Configuration
Least stable, but highest energy. 0-60 or 60-180 degrees
What is the stability hierarchy?
Anti>Gauche>Eclipsed
Cyclopropane properties as a chair
Locked in plane, lots of angle strain, eclipsed
Cyclobutene properties as a chair
lots of angle strain, slightly folded
Cyclopentane
Minimal angle strain (108 vs. 109.5), several eclipsed interactions
Cyclohexane
no angle strain, no eclipsed reactions if drawn in a chair.
Axial
Same direction as the chair angle
Equatorial
Opposite angle as the chair.
Do chairs exist in axial or equatorial more?
Equatorial
Cis
Same side
Trans
Opposite sides
Stereoisomer
Same formula, same configuration, different spatial arrangements
Constitutional isomers
Same formula, different configuration
Enantiomers
Stereoisomers whose molecules are non-super imposable mirror images.
Diastereomers
Stereoisomers whose molecules are NOT mirror images
Chiral molecule
Molecule that is not superposable on its mirror image
Achiral
Superposable on its mirror image
Chiral center
4 different groups attached to a C
Which is which in R and S being clock or counter clockwise?
R is clockwise
S is counterclockwise
Mesocompounds
Compounds that have chiral centers, but are achiral
What is the requirement to be a mesocompound?
Has to have an internal plane of symmetry
Optically active
Ability to rotate plane polarized light
Are chiral molecules optically active or inactive?
Optically active
What do enantiomers have to do with plane polarized light?
They have equal, but opposite, specific optical rotations
What is the formula and symbols for specific rotation?
[a]= a/c*L
where [a] is specific rotation
a = observed rotation
c is concentration ins g/ml
L is pathlength in 1/10 cm
If positive for specific rotation
dextrorotary or clockwise
If negative for specific rotation
Levorotary or counterclockwise
Optically or enantiomerically pure
1 enantiomer
Racemic mixture
Equal amounts of 2 enantiomers (optically inactive)
When using the EZ system, is e or z on same or opposite side?
Same size: Z
Opposite side: E
Whats a bronstead acid and base
Acid: proton donor
Base: proton receiver
Whats a lewis acid and base?
Acid: Electron pair acceptor
Base: Electron pair donor.
Whats a mechanism?
the detailed movement of electrons using curly arrows?
Does a reaction lie towards the bigger or smaller PKA
Weaker acid or higher PKA