Flashcards in Unit 4 - Comfomations Deck (20)
What are Conformations?
Different rotational arrangements around an sp3 hybridized bond
What is the Torsion Angle?
The angle between the C-H bond in the front and the angle between the C-H bond in the back
What does Torsional Strain arise from?
Repulsion of electrons in the bonds of adjacent atoms. So when an atom in the front and the back are eclipsing each other or large. Eclipsed vs Staggered
What is the staggered conformation?
When there is 60° between each bond
What is Steric Strain?
Repulsive forces within a molecule that arise repulsion of electron cloud substituents like in gauche their electron clouds repulse each other
What is Anti-Planar?
When the two large substituents are on opposite sides in staggered
What is Totally eclipsed?
When the two big substituents are one in front of the other
What is Gauche?
When the two large substituents are next to each other in staggered position
What is Partially eclipsed?
When one big substituent is is eclipsing a small one like hydrogen
How does Cyclopropane experience angle strain?
It is in a triangle so it wants to have bond angles of 60° but but the ideal bond angle is 109.5° because it is sp3 hybridized so the overlap of the hybridized orbitals is decreased
How does cyclopropane experience Torsional Strain?
Every C-H bond is eclipsed
What strains does Cyclopropane experience!
Angle strain and Torsional strain
What strains does cyclobutane experience?
Cyclobutane experiences Torsional Strain and Angle Strain
How can the strain on Cyclobutane be alleviated?
By using the butterfly conformation with brings two opposite corners up. Removes angle strain and torsional strain by fixing the ideal angles and not being eclipsed
What kind of strain does Cyclopentane have?
Torsional strain and Angle strain
How is the strains in Cyclopentane fixed?
By moving one of the corners up it relieves the torsional strain in a portion of the molecule
How is the Strain in Cyclohexane relieved?
By creating the chair conformation
Which substitutents are axial in the chair conformation?
The ones that go directly up or down
How does the chair conformation fix things in chclohexane?
It gets rid of the eclipsing so everything is perfecting staggered