## CH3OHCH, didehydro-dimethylether onium cation (*see note)

 H3 C7 - H8 | / H5 - C1 - O2 | \ H4 H6
The ion charge is 1.

## Atomic Charges and Dipole Moment

C1 charge=-0.058
O2 charge= 0.234
H3 charge= 0.142
H4 charge= 0.153
H5 charge= 0.152
H6 charge= 0.325
C7 charge=-0.284
H8 charge= 0.333
with a dipole moment of 3.18375 Debye

## Bond Lengths:

between C1 and O2: distance=1.549 ang___ between C1 and H3: distance=1.099 ang___
between C1 and H4: distance=1.099 ang___ between C1 and H5: distance=1.099 ang___
between O2 and H6: distance=1.006 ang___ between O2 and C7: distance=1.371 ang___
between C7 and H8: distance=1.122 ang___

## Bond Angles:

for H3-C1-O2: angle=102.5 deg___ for H4-C1-O2: angle=105.3 deg___
for H5-C1-O2: angle=105.3 deg___ for H6-O2-C1: angle=114.4 deg___
for C7-O2-C1: angle=120.5 deg___ for H8-O2-C1: angle=154.5 deg___

## Bond Orders (Mulliken):

between C1 and O2: order=0.481___ between C1 and H3: order=0.942___
between C1 and H4: order=0.943___ between C1 and H5: order=0.943___
between O2 and H6: order=0.717___ between O2 and C7: order=0.861___
between C7 and H8: order=0.915___

## 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 C1-O2 with 1.9951 electrons
__has 21.38% C 1 character in a s0.57 p3 hybrid
__has 78.62% O 2 character in a sp1.97 hybrid

2. A bonding orbital for C1-H3 with 1.9922 electrons
__has 62.11% C 1 character in a sp2.53 hybrid
__has 37.89% H 3 character in a s orbital

3. A bonding orbital for C1-H4 with 1.9929 electrons
__has 60.98% C 1 character in a sp2.57 hybrid
__has 39.02% H 4 character in a s orbital

4. A bonding orbital for C1-H5 with 1.9930 electrons
__has 60.99% C 1 character in a sp2.56 hybrid
__has 39.01% H 5 character in a s orbital

5. A bonding orbital for O2-H6 with 1.9946 electrons
__has 80.10% O 2 character in a sp2.70 hybrid
__has 19.90% H 6 character in a s orbital

6. A bonding orbital for O2-C7 with 1.9961 electrons
__has 78.36% O 2 character in a sp1.53 hybrid
__has 21.64% C 7 character in a s0.61 p3 hybrid

7. A bonding orbital for O2-C7 with 1.9937 electrons
__has 94.58% O 2 character in a p-pi orbital ( 99.99% p)
__has 5.42% C 7 character in a p-pi orbital ( 98.79% p 1.21% d)

8. A bonding orbital for C7-H8 with 1.9777 electrons
__has 54.38% C 7 character in a s0.81 p3 hybrid
__has 45.62% H 8 character in a s orbital

12. A lone pair orbital for C7 with 1.9787 electrons

-With core pairs on: C 1 O 2 C 7 -

#### 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, 8, for C7-H8 with the antibonding acceptor orbital, 95, for C1-O2 is 23.8 kJ/mol.

The interaction of bonding donor orbital, 8, for C7-H8 with the antibonding acceptor orbital, 100, for O2-C7 is 23.4 kJ/mol.

The interaction of lone pair donor orbital, 12, for C7 with the antibonding acceptor orbital, 99, for O2-H6 is 31.6 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.

16 ----- -3.378

15 ----- -5.844

14 ----- -7.627

13 ----- -10.25

12 -^-v- -12.22

11 -^-v- -16.17

10 -^-v- -16.60

9 -^-v- -18.27

8 -^-v- -19.31

7 -^-v- -20.80

6 -^-v- -24.54

5 -^-v- -25.84

4 -^-v- -36.06

3 -^-v- -274.5

2 -^-v- -275.6

1 -^-v- -518.0

## 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 = -154.0336290236 Hartrees