## Bromoethane, CH3CH2Br

 H3 H8 BR7 \ | / H5 - C1 - C2 / \ H4 H6
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

C1 charge=-0.201
C2 charge=-0.073
H3 charge= 0.082
H4 charge= 0.082
H5 charge= 0.087
H6 charge= 0.103
BR7 charge=-0.187
H8 charge= 0.105
with a dipole moment of 2.31776 Debye

## Bond Lengths:

between C1 and C2: distance=1.521 ang___ between C1 and H3: distance=1.102 ang___
between C1 and H4: distance=1.102 ang___ between C1 and H5: distance=1.107 ang___
between C2 and H6: distance=1.100 ang___ between C2 and BR7: distance=2.007 ang___
between C2 and H8: distance=1.099 ang___

## Bond Angles:

for H3-C1-C2: angle=111.5 deg___ for H4-C1-C2: angle=111.4 deg___
for H5-C1-C2: angle=109.2 deg___ for H6-C2-C1: angle=112.8 deg___
for BR7-C2-C1: angle=111.4 deg___ for H8-C2-C1: angle=113.0 deg___

## Bond Orders (Mulliken):

between C1 and C2: order=1.044___ between C1 and H3: order=0.963___
between C1 and H4: order=0.963___ between C1 and H5: order=0.947___
between C2 and H6: order=0.930___ between C2 and BR7: order=1.042___
between C2 and H8: order=0.930___

## 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-C2 with 1.9983 electrons
__has 48.39% C 1 character in a sp2.57 hybrid
__has 51.61% C 2 character in a sp2.12 hybrid

2. A bonding orbital for C1-H3 with 1.9905 electrons
__has 61.32% C 1 character in a s0.96 p3 hybrid
__has 38.68% H 3 character in a s orbital

3. A bonding orbital for C1-H4 with 1.9905 electrons
__has 61.33% C 1 character in a s0.96 p3 hybrid
__has 38.67% H 4 character in a s orbital

4. A bonding orbital for C1-H5 with 1.9790 electrons
__has 60.84% C 1 character in a s0.93 p3 hybrid
__has 39.16% H 5 character in a s orbital

5. A bonding orbital for C2-H6 with 1.9907 electrons
__has 62.18% C 2 character in a sp2.78 hybrid
__has 37.82% H 6 character in a s orbital

6. A bonding orbital for C2-Br7 with 1.9903 electrons
__has 43.85% C 2 character in a s0.54 p3 hybrid
__has 56.15% Br 7 character in a s0.44 p3 hybrid

7. A bonding orbital for C2-H8 with 1.9907 electrons
__has 62.18% C 2 character in a sp2.77 hybrid
__has 37.82% H 8 character in a s orbital

24. A lone pair orbital for Br7 with 1.9974 electrons

25. A lone pair orbital for Br7 with 1.9905 electrons
__made from a p-pi orbital ( 99.98% p)

26. A lone pair orbital for Br7 with 1.9873 electrons

-With core pairs on: C 1 C 2 Br 7 Br 7 Br 7 Br 7 Br 7 Br 7 Br 7 Br 7 Br 7 Br 7 Br 7 Br 7 Br 7 Br 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, 4, for C1-H5 with the antibonding acceptor orbital, 96, for C2-Br7 is 37.9 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.

30 ----- 2.912

29 ----- 1.674
28 ----- 1.565

27 ----- -1.403

26 -^-v- -6.584
25 -^-v- -6.642

24 -^-v- -8.689

23 -^-v- -9.022

22 -^-v- -10.04

21 -^-v- -10.92

20 -^-v- -11.60

19 -^-v- -15.16

18 -^-v- -18.12

17 -^-v- -20.23

16 -^-v- -67.88 15 -^-v- -67.88

14 -^-v- -68.17 13 -^-v- -68.18

12 -^-v- -68.28

11 -^-v- -171.1 10 -^-v- -171.1

9 -^-v- -171.5

8 -^-v- -228.6

7 -^-v- -266.5

6 -^-v- -267.9

5 -^-v- -1517. 4 -^-v- -1517.
3 -^-v- -1517.

2 -^-v- -1680.

1 -^-v- -13066

## 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 = -2653.2433581911 Hartrees