## B(OH)4-, Boric acid's anion

 H4 \ H9 O3 | / O1 - B2 - O7 - H8 \ O5 - H6
The ion charge is -1.

## Atomic Charges and Dipole Moment

O1 charge=-0.855
B2 charge= 1.103
O3 charge=-0.855
H4 charge= 0.329
O5 charge=-0.855
H6 charge= 0.329
O7 charge=-0.856
H8 charge= 0.331
H9 charge= 0.329
with a dipole moment of 7.14305 Debye

## Bond Lengths:

between O1 and B2: distance=1.505 ang___ between O1 and O5: distance=2.372 ang___
between O1 and H9: distance=0.973 ang___ between B2 and O3: distance=1.507 ang___
between B2 and O5: distance=1.506 ang___ between B2 and O7: distance=1.505 ang___
between O3 and H4: distance=0.973 ang___ between O3 and O7: distance=2.374 ang___
between O5 and H6: distance=0.973 ang___ between O7 and H8: distance=0.973 ang___

## Bond Angles:

for O3-B2-O1: angle=112.3 deg___ for H4-O3-B2: angle=104.1 deg___
for O5-B2-O1: angle=103.9 deg___ for H6-O5-B2: angle=104.1 deg___
for O7-B2-O1: angle=112.2 deg___ for H8-O7-B2: angle=104.1 deg___
for H9-O1-B2: angle=104.2 deg___

## Bond Orders (Mulliken):

between O1 and B2: order=0.896___ between O1 and O5: order=-0.130___
between O1 and H9: order=0.893___ between B2 and O3: order=0.894___
between B2 and O5: order=0.895___ between B2 and O7: order=0.895___
between O3 and H4: order=0.893___ between O3 and O7: order=-0.129___
between O5 and H6: order=0.893___ between O7 and H8: order=0.893___

## 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 O1-B2 with 1.9939 electrons
__has 81.17% O 1 character in a sp1.50 hybrid
__has 18.83% B 2 character in a sp2.98 hybrid

2. A bonding orbital for O1-H9 with 1.9856 electrons
__has 71.90% O 1 character in a s0.67 p3 hybrid
__has 28.10% H 9 character in a s orbital

3. A bonding orbital for B2-O3 with 1.9939 electrons
__has 18.83% B 2 character in a sp2.98 hybrid
__has 81.17% O 3 character in a sp1.51 hybrid

4. A bonding orbital for B2-O5 with 1.9939 electrons
__has 18.83% B 2 character in a sp2.98 hybrid
__has 81.17% O 5 character in a sp1.51 hybrid

5. A bonding orbital for B2-O7 with 1.9939 electrons
__has 18.83% B 2 character in a sp2.98 hybrid
__has 81.17% O 7 character in a sp1.50 hybrid

6. A bonding orbital for O3-H4 with 1.9856 electrons
__has 71.90% O 3 character in a s0.67 p3 hybrid
__has 28.10% H 4 character in a s orbital

7. A bonding orbital for O5-H6 with 1.9856 electrons
__has 71.90% O 5 character in a s0.66 p3 hybrid
__has 28.10% H 6 character in a s orbital

8. A bonding orbital for O7-H8 with 1.9855 electrons
__has 71.91% O 7 character in a s0.67 p3 hybrid
__has 28.09% H 8 character in a s orbital

14. A lone pair orbital for O1 with 1.9797 electrons

15. A lone pair orbital for O1 with 1.9593 electrons
__made from a p-pi orbital ( 99.96% p)

16. A lone pair orbital for O3 with 1.9798 electrons

17. A lone pair orbital for O3 with 1.9595 electrons
__made from a p-pi orbital ( 99.96% p)

18. A lone pair orbital for O5 with 1.9798 electrons

19. A lone pair orbital for O5 with 1.9594 electrons
__made from a p-pi orbital ( 99.96% p)

20. A lone pair orbital for O7 with 1.9798 electrons

21. A lone pair orbital for O7 with 1.9593 electrons
__made from a p-pi orbital ( 99.96% p)

-With core pairs on: O 1 B 2 O 3 O 5 O 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 the second lone pair donor orbital, 15, for O1 with the antibonding acceptor orbital, 139, for B2-O3 is 47.4 kJ/mol.

The interaction of the second lone pair donor orbital, 15, for O1 with the antibonding acceptor orbital, 141, for B2-O7 is 48.2 kJ/mol.

The interaction of the second lone pair donor orbital, 17, for O3 with the antibonding acceptor orbital, 137, for O1-B2 is 47.7 kJ/mol.

The interaction of the second lone pair donor orbital, 17, for O3 with the antibonding acceptor orbital, 140, for B2-O5 is 47.3 kJ/mol.

The interaction of the second lone pair donor orbital, 19, for O5 with the antibonding acceptor orbital, 139, for B2-O3 is 48.2 kJ/mol.

The interaction of the second lone pair donor orbital, 19, for O5 with the antibonding acceptor orbital, 141, for B2-O7 is 47.1 kJ/mol.

The interaction of the second lone pair donor orbital, 21, for O7 with the antibonding acceptor orbital, 137, for O1-B2 is 47.2 kJ/mol.

The interaction of the second lone pair donor orbital, 21, for O7 with the antibonding acceptor orbital, 140, for B2-O5 is 48.2 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.

25 ----- 6.753

24 ----- 5.801 23 ----- 5.800
22 ----- 5.629

21 -^-v- -0.345

20 -^-v- -1.003 19 -^-v- -1.003

18 -^-v- -1.832

17 -^-v- -1.957

16 -^-v- -3.779 15 -^-v- -3.783
14 -^-v- -3.815

13 -^-v- -4.823 12 -^-v- -4.825

11 -^-v- -7.431

10 -^-v- -7.687

9 -^-v- -17.93

8 -^-v- -18.08 7 -^-v- -18.08

6 -^-v- -19.43

5 -^-v- -170.4

4 -^-v- -500.1 3 -^-v- -500.1 2 -^-v- -500.1 1 -^-v- -500.1

## 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 = -328.4963543636 Hartrees