Orgo Lecture

Nodal plane

goes between antibonding orbitals.

hund

single fill orbitals of equal energy before pairing e-

Electron delocalization

stabilizes the resonance structure.

Hybridization

combining multiple individual wave functions to get a new wave function for a new orbital.

Boron can

promote a 2s e- to a 2p e,- creating 3 sp2 orbitals.

LCAO

combining wave functions linearly to get a new wave function for the molecular orbital.

Aufbau

orbitals filled from lowest to highest energy level.

Covalent bond

sharing electrons between atoms.

Octet rule

atoms tend to gain or lose e- to obtain noble gas configuration (8 val e)-

Ionic bond

coulombic attraction between an e- rich and e- poor atom.

When 2+ atoms can support formal charge

the more EN atom is more stable with (--) charge.

covalent bond

sharing electrons between atoms

octet rule mainly applies to

second row elements

BF3 is

very reactive with compounds that have LPE

PCl5 and SF5

have over-filled val shell

balanced formal charge

more stable than other versions of the same compound

resonance structures

more than one possible lewis structure

resonance structures are really

hybrid orbitals that exist in an inbetween form rather than multiple distinct resonance forms

possible resonance structures can be drawn as

multiple structures or one structure with delocalized e-

each resonance structure should have the same e

and the same net charge

lewis structure cannot

predict molecular geometry

VSEPR

LPE will stay as far from each other as possible to minimize repulsion between them

lewis structure + VSEPR can

predict molecular geometry

tetrahedral bond angle

109.5°

trigonal planar bond angle

120°

molecular orbital theory question

why atoms need to come together in covalent bonds (why bonding releases energy)

LCAO derived from

schrödingers equation and wave function

LCAO

combining wave functions linearly to get a new wave function for the molecular orbital

e

fill the MOs according to Aufbau, Pauli, and Hund

Aufbau

orbitals filled from lowest to highest energy level

hund

single fill orbitals of equal energy before pairing e-

hybridization

combining multiple individual wave functions to get a new wave function for a new orbital

sp orbital shape

uneven dumbell

sp orbital can

form sigma bonds with other s orbitals (bonding if same sign, antibonding if different)

bonding orbital

effective overlap

antibonding orbital

ineffective overlap

sp3 hybridization molecular structure

tetrahedral

pi bond

double bond, p orbital dumbells line up (either bonding or antibonding)

sigma bond

single bond only

nodal plane

goes between antibonding orbitals