## 3-dehydrobutene cation, CH2=CHC(+)HCH3 (see note)

 H9 H4 | | C7 C3 H6 / | \ / || / H8 H10 C1 - C2 | | H11 H5
The ion charge is 1.

## Atomic Charges and Dipole Moment

C1 charge= 0.267
C2 charge=-0.073
C3 charge=-0.121
H4 charge= 0.192
H5 charge= 0.186
H6 charge= 0.217
C7 charge=-0.492
H8 charge= 0.240
H9 charge= 0.213
H10 charge= 0.238
H11 charge= 0.131
with a dipole moment of 3.45210 Debye

## Bond Lengths:

between C1 and C2: distance=2.408 ang___ between C1 and C3: distance=1.413 ang___
between C1 and C7: distance=1.451 ang___ between C1 and H9: distance=2.168 ang___
between C1 and H11: distance=1.103 ang___ between C2 and C3: distance=1.378 ang___
between C2 and H5: distance=1.099 ang___ between C2 and H6: distance=1.097 ang___
between C2 and C7: distance=3.775 ang___ between C3 and H4: distance=1.098 ang___
between C3 and H5: distance=2.163 ang___ between C3 and H11: distance=2.155 ang___
between C7 and H8: distance=1.116 ang___ between C7 and H9: distance=1.099 ang___
between C7 and H10: distance=1.118 ang___

## Bond Angles:

for C3-C1-C2: angle=29.92 deg___ for H4-C3-C1: angle=119.7 deg___
for H5-C2-C1: angle=90.52 deg___ for H6-C2-C1: angle=152.3 deg___
for C7-C1-C2: angle=155.2 deg___ for H8-C7-C1: angle=109.5 deg___
for H9-C7-C1: angle=115.7 deg___ for H10-C7-C1: angle=108.1 deg___
for H11-C1-C2: angle=87.45 deg___

## Bond Orders (Mulliken):

between C1 and C2: order=0.388___ between C1 and C3: order=1.196___
between C1 and C7: order=0.794___ between C1 and H9: order=-0.084___
between C1 and H11: order=0.926___ between C2 and C3: order=1.336___
between C2 and H5: order=0.984___ between C2 and H6: order=0.942___
between C2 and C7: order=0.053___ between C3 and H4: order=0.900___
between C3 and H5: order=-0.096___ between C3 and H11: order=-0.058___
between C7 and H8: order=0.919___ between C7 and H9: order=1.006___
between C7 and H10: order=0.925___

## 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 C1-C3 with 1.9896 electrons
__has 49.20% C 1 character in a sp1.77 hybrid
__has 50.80% C 3 character in a sp1.94 hybrid

2. A bonding orbital for C1-C7 with 1.9928 electrons
__has 50.61% C 1 character in a sp1.79 hybrid
__has 49.39% C 7 character in a sp2.33 hybrid

3. A bonding orbital for C1-H11 with 1.9800 electrons
__has 60.55% C 1 character in a sp2.54 hybrid
__has 39.45% H11 character in a s orbital

4. A bonding orbital for C2-C3 with 1.9921 electrons
__has 48.06% C 2 character in a sp1.58 hybrid
__has 51.94% C 3 character in a sp1.81 hybrid

5. A bonding orbital for C2-C3 with 1.6496 electrons
__has 32.05% C 2 character in a p-pi orbital ( 99.77% p 0.23% d)
__has 67.95% C 3 character in a p-pi orbital ( 99.89% p 0.11% d)

6. A bonding orbital for C2-H5 with 1.9887 electrons
__has 60.37% C 2 character in a sp2.27 hybrid
__has 39.63% H 5 character in a s orbital

7. A bonding orbital for C2-H6 with 1.9888 electrons
__has 61.36% C 2 character in a sp2.23 hybrid
__has 38.64% H 6 character in a s orbital

8. A bonding orbital for C3-H4 with 1.9818 electrons
__has 62.97% C 3 character in a sp2.26 hybrid
__has 37.03% H 4 character in a s orbital

9. A bonding orbital for C7-H8 with 1.9485 electrons
__has 63.13% C 7 character in a s0.85 p3 hybrid
__has 36.87% H 8 character in a s orbital

10. A bonding orbital for C7-H9 with 1.9907 electrons
__has 62.27% C 7 character in a sp2.77 hybrid
__has 37.73% H 9 character in a s orbital

11. A bonding orbital for C7-H10 with 1.9417 electrons
__has 63.12% C 7 character in a s0.82 p3 hybrid
__has 36.88% H10 character in a s orbital

16. A lone pair orbital for C1 with 0.4411 electrons
__made from a p-pi orbital ( 99.91% p 0.09% d)

-With core pairs on: C 1 C 2 C 3 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, 3, for C1-H11 with the antibonding acceptor orbital, 135, for C3-H4 is 22.5 kJ/mol.

The interaction of the second bonding donor orbital, 5, for C2-C3 with the lone pair acceptor orbital, 16, for C1 is 636. kJ/mol.

The interaction of bonding donor orbital, 6, for C2-H5 with the antibonding acceptor orbital, 135, for C3-H4 is 23.2 kJ/mol.

The interaction of bonding donor orbital, 7, for C2-H6 with the antibonding acceptor orbital, 128, for C1-C3 is 26.3 kJ/mol.

The interaction of bonding donor orbital, 9, for C7-H8 with the lone pair acceptor orbital, 16, for C1 is 60.0 kJ/mol.

The interaction of bonding donor orbital, 11, for C7-H10 with the lone pair acceptor orbital, 16, for C1 is 72.6 kJ/mol.

The interaction of lone pair donor orbital, 16, for C1 with the second antibonding acceptor orbital, 132, for C2-C3 is 63.5 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.

19 ----- -3.353
18 ----- -3.411

17 ----- -6.459

16 ----- -10.42

15 -^-v- -13.84

14 -^-v- -14.63

13 -^-v- -15.30

12 -^-v- -15.44

11 -^-v- -16.03

10 -^-v- -17.48

9 -^-v- -17.59

8 -^-v- -19.76

7 -^-v- -21.54

6 -^-v- -24.44

5 -^-v- -26.54

4 -^-v- -272.0

3 -^-v- -272.9

2 -^-v- -273.6

1 -^-v- -274.3

## 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 = -156.3525528897 Hartrees