3 Conformations Flashcards
Different rotational arrangements are called
conformations
Different conformations require different amounts of _____
energy
what are the 3 types of strain
Angle strain
Torsional strain
Steric strain
what is angle strain
- Torturing a molec into a not ideal geometry (raises energy)
- Orbitals with bad overlap (because they don’t want to be in a not ideal geometry)
3 membered rings have _____ angle strain
tremendous
what is the most common reason for angle strain
unusual geometry
what is torsional strain
- e- clouds from 2 atoms that are separated by exactly 3 bonds coming too close together (negative charges are repelling)
- Like a dihedral side angle (H’s lined up exactly w each other)
torsional strain has a ____ energy cost associated with it
low
what is steric strain
- 2 atoms that are not bonded together being close in proximity
TF ATs considered non bonded if they are separated by 2 bonds (or if on diff molecs)
F , its 3 or more bonds
what is an example of massive steric strain
heavily overlapping electron clouds.
what are 5 diff types of conformations
○ Eclipsed
○ Staggered
○ Antiperiplanar
○ Gauche
○ Partially eclipsed
what does the antiperiplanar confomration look like
2 large/high priority substituents are the max distance from eachother
what does a gauche conformation look like
Staggered but large/high priority grps r close to each other
what does a partially eclipsed conformation look like
Largest/priority groups are eclipsed but with a smaller atom
