Unit 4 - Comfomations Flashcards Preview

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Flashcards in Unit 4 - Comfomations Deck (20)
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1

What are Conformations?

Different rotational arrangements around an sp3 hybridized bond

2

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

3

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

4

What is the staggered conformation?

When there is 60° between each bond

5

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

6

What is Anti-Planar?

When the two large substituents are on opposite sides in staggered

7

What is Totally eclipsed?

When the two big substituents are one in front of the other

8

What is Gauche?

When the two large substituents are next to each other in staggered position

9

What is Partially eclipsed?

When one big substituent is is eclipsing a small one like hydrogen

10

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

11

How does cyclopropane experience Torsional Strain?

Every C-H bond is eclipsed

12

What strains does Cyclopropane experience!

Angle strain and Torsional strain

13

What strains does cyclobutane experience?

Cyclobutane experiences Torsional Strain and Angle Strain

14

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

15

What kind of strain does Cyclopentane have?

Torsional strain and Angle strain

16

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

17

How is the Strain in Cyclohexane relieved?

By creating the chair conformation

18

Which substitutents are axial in the chair conformation?

The ones that go directly up or down

19

How does the chair conformation fix things in chclohexane?

It gets rid of the eclipsing so everything is perfecting staggered

20

What are the rules in ring flips?

Up stays up and down stays down. Equatorial goes to axial and axial goes to equatorial