HF % ionic = 100%x(1-e-(4.0-2.1)2/4) = 59%

HCl % ionic = 100%x(1-e-(3.0-2.1)2/4) = 18%

HBr % ionic = 100%x(1-e-(2.8-2.1)2/4) = 12%

HI % ionic = 100%x(1-e-(2.5-2.1)2/4) = 4%

KF % ionic = 100%x(1-e-(4.0-0.8)2/4) = 92%

Qualitative Molecular Orbital Theory (QMOT)

Group Orbitals

Walsh Diagrams: A diagram that follows orbital energies as a function of angular distortions

Mixing of two MOs of water molecule

Stability of Allyl unit

17

CH3CH3CH—H 410 kJ/mol

CH3CH2CH2 + H•

•

368 kJ/mol + H•

•

CHCH2—H H2C CHCH2 H2C

C—H bond is weaker in propene because the resulting allyl

radical is more stable than the alkyl radicals.

Free Radical Stabilities are Related to Bond-Dissociation Energies

(CH3)3C—H

(CH3)2CH—H

(CH3)3C

(CH3)2CH

•

•

+ H•

+ H•

397 kJ/mol

380 kJ/mol

Carbene + ium ions

Carbenium ions (CH3+)

Planar vs. Pyramidal

30 kJ/mol

stabilities for carbenium ions is

3° > 2° > 1°> methyl.

Ethyl Carbenium Ion

Charge on CH3 is +0.17 C-C bond length 1.425 Å C-H bond length longer C-C-H bond angle 95°

Carbonium Ions

Non-classical Carbocation

Carbanion

Planar vs. Pyramidal???

Benzyl anion

Radicals

Planar vs. Pyramidal???

CH3. vs. CF3.

A Carbene that is stable for ages!!!

M=CR2