Best Lewis Structure
The Lewis structure that is closest to your structure is determined.
The hybridization of the atoms in this idealized Lewis structure
is given in the table below.
Hybridization in the Best Lewis Structure
1. A bonding orbital for Al1-C2 with 1.9831 electrons
__has 19.37% Al 1 character in a sp1.80 hybrid
__has 80.63% C 2 character in a sp2.41 hybrid
2. A bonding orbital for Al1-H3 with 1.9781 electrons
__has 27.90% Al 1 character in a sp2.07 hybrid
__has 72.10% H 3 character in a s orbital
3. A bonding orbital for Al1-H4 with 1.9779 electrons
__has 27.93% Al 1 character in a sp2.06 hybrid
__has 72.07% H 4 character in a s orbital
4. A bonding orbital for C2-H5 with 1.9963 electrons
__has 60.68% C 2 character in a s0.96 p3 hybrid
__has 39.32% H 5 character in a s orbital
5. A bonding orbital for C2-H6 with 1.9928 electrons
__has 60.64% C 2 character in a s0.92 p3 hybrid
__has 39.36% H 6 character in a s orbital
6. A bonding orbital for C2-H7 with 1.9906 electrons
__has 60.58% C 2 character in a s0.90 p3 hybrid
__has 39.42% H 7 character in a s orbital
-With core pairs on:Al 1 Al 1 Al 1 Al 1 Al 1 C 2 -
Top of page.
Donor Acceptor Interactions in the Best Lewis Structure
The localized orbitals in your best Lewis structure
can interact strongly. A filled bonding or lone pair orbital can
act as a donor and an empty or filled bonding, antibonding, or
lone pair orbital can act as an acceptor. These
interactions can strengthen and weaken bonds. For example, a
lone pair donor->antibonding acceptor orbital interaction
will weaken the bond
associated with the antibonding orbital. Conversly, an interaction
with a bonding pair as the acceptor will strengthen the bond.
Strong electron delocalization in your best Lewis structure will
also show up as donor-acceptor interactions.
Interactions greater than 20 kJ/mol for bonding and lone pair
orbitals are listed below.
The interaction of bonding donor orbital, 2, for Al1-H3 with
the antibonding acceptor orbital, 80, for Al1-C2 is 27.5 kJ/mol.
The interaction of bonding donor orbital, 2, for Al1-H3 with
the antibonding acceptor orbital, 82, for Al1-H4 is 20.4 kJ/mol.
The interaction of bonding donor orbital, 3, for Al1-H4 with
the antibonding acceptor orbital, 80, for Al1-C2 is 28.9 kJ/mol.
The interaction of bonding donor orbital, 3, for Al1-H4 with
the antibonding acceptor orbital, 81, for Al1-H3 is 20.2 kJ/mol.
Top of page.
Molecular Orbital Energies
The orbital energies are given in eV, where 1 eV=96.49 kJ/mol.
Orbitals with very low energy are core 1s orbitals.
More antibonding orbitals than you might expect are sometimes
listed, because d orbitals are always included for heavy
atoms and p orbitals are included for H atoms.
Up spins are shown with a ^ and down spins are shown as v.
16 ----- 1.614
15 ----- 1.089
14 ----- -0.212
13 ----- -2.302
12 -^-v- -6.843
11 -^-v- -6.964
10 -^-v- -9.523
9 -^-v- -9.571
8 -^-v- -9.834
7 -^-v- -16.51
6 -^-v- -68.57 5 -^-v- -68.58
4 -^-v- -69.07
3 -^-v- -105.9
2 -^-v- -265.6
1 -^-v- -1499.
Top of page.
Total Electronic Energy
The total electronic energy is a very large number, so by convention
the units are given in atomic units, that is Hartrees (H). One
Hartree is 2625.5 kJ/mol. The energy reference is for totally
dissociated atoms. In other words, the reference state is a gas
consisting of nuclei and electrons all at infinite distance from
each other. The electronic energy includes all electric
interactions and the kinetic energy of the electrons. This energy
does not include translation, rotation, or vibration of the
the molecule.
Total electronic energy = -283.5590816782 Hartrees
Top of page.
-> Return to Molecular Structure Page.
-> Return to Chemistry Home Page