Chapter 12 - Molecular Orbital Theory

atomic orbital theory

describes electron distribution with each orbital holding up to 2 electrons in atoms, act as a wave function

molecular orbital theory

describes electron distribution with each orbital holding up to 2 electrons in molecules, act as a wave function, the better model for bonding

bonding orbital

come from in-phase orbitals, combine/build

antibonding orbital

come from out of phase orbitals, split apart/shift

bonding orbital in sigma bonds

are head to head, in phase

antibonding orbital in sigma bonds

opposing sides face each other, out of phase

molecular orbital energy diagrams

shows relative energy levels of atomic and molecular orbitals

bond order

the # of pairs of electrons between atoms (is also = to # of bonds in a Lewis Structure), the larger the # the higher the strength

calculating bond order

(# of pairs of electrons between atoms - # of antiboding electrons) / 2

what happens when the bond order is less than or equal to 0?

no stable bond is formed

s-p mixing

causes sigma p orbitals to be less stable than pi p orbitals due to mixing s + p based molecular orbitals of similar energies