## CCO cyclic isomer (*see note)

 C3 / | O1 - C2
Tell me about the atomic charges, dipole moment, bond lengths, angles, bond orders,
molecular orbital energies, or total energy.
Tell me about the best Lewis structure.

## Atomic Charges and Dipole Moment

O1 charge= 0.126
C2 charge=-0.063
C3 charge=-0.062
with a dipole moment of 0.64103 Debye

## Bond Lengths:

between O1 and C2: distance=1.371 ang___ between O1 and C3: distance=1.371 ang___
between C2 and C3: distance=1.518 ang___

## Bond Angles:

for C3-O1-C2: angle=67.24 deg___

## Bond Orders (Mulliken):

between O1 and C2: order=1.001___ between O1 and C3: order=1.001___
between C2 and C3: order=1.138___

## 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. Please note that your structure can't be well described by a single Lewis structure, because of extensive delocalization.

### Hybridization in the Best Lewis Structure

1. A bonding orbital for O1-C2 with 1.9910 electrons
__has 74.07% O 1 character in a s0.80 p3 hybrid
__has 25.93% C 2 character in a s0.45 p3 hybrid

2. A bonding orbital for O1-C2 with 1.7807 electrons
__has 87.69% O 1 character in a p-pi orbital ( 99.80% p 0.20% d)
__has 12.31% C 2 character in a p-pi orbital ( 98.29% p 1.71% d)

3. A bonding orbital for O1-C3 with 1.9910 electrons
__has 74.07% O 1 character in a s0.80 p3 hybrid
__has 25.93% C 3 character in a s0.45 p3 hybrid

4. A bonding orbital for C2-C3 with 1.9923 electrons
__has 50.00% C 2 character in a s0.55 p3 hybrid
__has 50.00% C 3 character in a s0.55 p3 hybrid

8. A lone pair orbital for O1 with 1.9924 electrons
__made from a sp0.72 hybrid

9. A lone pair orbital for C2 with 1.9935 electrons
__made from a sp0.37 hybrid

10. A lone pair orbital for C3 with 1.9935 electrons
__made from a sp0.37 hybrid

11. A lone pair orbital for C3 with 0.2192 electrons
__made from a p-pi orbital ( 98.29% p 1.71% d)

-With core pairs on: O 1 C 2 C 3 -

#### 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, 1, for O1-C2 with the antibonding acceptor orbital, 71, for O1-C3 is 28.4 kJ/mol.

The interaction of the second bonding donor orbital, 2, for O1-C2 with the second lone pair acceptor orbital, 11, for C3 is 521. kJ/mol.

The interaction of bonding donor orbital, 3, for O1-C3 with the antibonding acceptor orbital, 69, for O1-C2 is 28.4 kJ/mol.

## 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.

14 ----- 1.084
13 ----- 0.985

12 ----- -3.540

11 ----- -5.496

10 -^-v- -7.073

9 -^-v- -7.993

8 -^-v- -10.95

7 -^-v- -13.46

6 -^-v- -16.04

5 -^-v- -17.28

4 -^-v- -31.00

3 -^-v- -270.1 2 -^-v- -270.1

1 -^-v- -511.2

## 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 = -151.2455305856 Hartrees

* Note: The linear CCO triplet is lowest in energy. The linear CCO singlet is also lower in energy than the cyclic isomer.