Answer the following questions for the MOs of 1,3-butadiene:a. Which are p bonding MOs, and which are p* antibonding MOs?b. Which MOs are symmetric, and which are antisymmetric?c. Which MO is the HOMO and which is the LUMO in the ground state?d. Which MO is the HOMO and which is the LUMO in the excited state?e. What is the relationship between the HOMO and the LUMO and symmetric and antisymmetric orbitals?
Molecule Polarity Bond Dipoles • how do you know if a diatomic molecule is polar or non polar —EN difference between atoms • how do you know if a triatomic molecule is polar or non polar —EN difference and shape • bond dipole - partial separation of charges that occurs when polar bonds form • molecular dipole (dipole moment) - representation of bond dipoles calculated by adding them together • bond dipoles vs molecular dipoles —bond dipoles add to give molecular dipole (unless they cancel each other) • larger EN difference—>larger dipole Octet Exceptions Incomplete Octets • molecules with boron, beryllium, hydrogen, or helium as central atom can have less than an octet
