## H2PO2-, Hypophosphite ion

 O3 \ H5 - P1 - O2 / H4
The ion charge is -1.

## Atomic Charges and Dipole Moment

P1 charge= 1.030
O2 charge=-0.822
O3 charge=-0.822
H4 charge=-0.192
H5 charge=-0.193
with a dipole moment of 2.35058 Debye

## Bond Lengths:

between P1 and O2: distance=1.538 ang___ between P1 and O3: distance=1.538 ang___
between P1 and H4: distance=1.473 ang___ between P1 and H5: distance=1.475 ang___
between O2 and O3: distance=2.714 ang___

## Bond Angles:

for O3-P1-O2: angle=123.8 deg___ for H4-P1-O2: angle=107.8 deg___
for H5-P1-O2: angle=107.9 deg___

## Bond Orders (Mulliken):

between P1 and O2: order=1.468___ between P1 and O3: order=1.467___
between P1 and H4: order=0.897___ between P1 and H5: order=0.897___
between O2 and O3: order=-0.174___

## 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 P1-O2 with 1.9901 electrons
__has 26.23% P 1 character in a sp2.31 d0.05 hybrid
__has 73.77% O 2 character in a sp2.05 hybrid

2. A bonding orbital for P1-O3 with 1.9901 electrons
__has 26.23% P 1 character in a sp2.31 d0.05 hybrid
__has 73.77% O 3 character in a sp2.05 hybrid

3. A bonding orbital for P1-H4 with 1.9743 electrons
__has 40.15% P 1 character in a s0.81 p3 d0.08 hybrid
__has 59.85% H 4 character in a s orbital

4. A bonding orbital for P1-H5 with 1.9743 electrons
__has 40.14% P 1 character in a s0.81 p3 d0.08 hybrid
__has 59.86% H 5 character in a s orbital

12. A lone pair orbital for O2 with 1.9845 electrons

13. A lone pair orbital for O2 with 1.8862 electrons
__made from a p-pi orbital ( 99.93% p 0.07% d)

14. A lone pair orbital for O2 with 1.8724 electrons

15. A lone pair orbital for O3 with 1.9845 electrons

16. A lone pair orbital for O3 with 1.8863 electrons
__made from a p-pi orbital ( 99.93% p 0.07% d)

17. A lone pair orbital for O3 with 1.8724 electrons

90. A antibonding orbital for P1-H4 with 0.1387 electrons
__has 59.85% P 1 character in a s0.81 p3 d0.08 hybrid
__has 40.15% H 4 character in a s orbital

91. A antibonding orbital for P1-H5 with 0.1388 electrons
__has 59.86% P 1 character in a s0.81 p3 d0.08 hybrid
__has 40.14% H 5 character in a s orbital

-With core pairs on: P 1 P 1 P 1 P 1 P 1 O 2 O 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, 3, for P1-H4 with the antibonding acceptor orbital, 88, for P1-O2 is 21.6 kJ/mol.

The interaction of bonding donor orbital, 3, for P1-H4 with the antibonding acceptor orbital, 89, for P1-O3 is 21.6 kJ/mol.

The interaction of bonding donor orbital, 4, for P1-H5 with the antibonding acceptor orbital, 88, for P1-O2 is 21.6 kJ/mol.

The interaction of bonding donor orbital, 4, for P1-H5 with the antibonding acceptor orbital, 89, for P1-O3 is 21.6 kJ/mol.

The interaction of the second lone pair donor orbital, 13, for O2 with the antibonding acceptor orbital, 90, for P1-H4 is 82.5 kJ/mol.

The interaction of the second lone pair donor orbital, 13, for O2 with the antibonding acceptor orbital, 91, for P1-H5 is 81.4 kJ/mol.

The interaction of the third lone pair donor orbital, 14, for O2 with the antibonding acceptor orbital, 89, for P1-O3 is 106. kJ/mol.

The interaction of the third lone pair donor orbital, 14, for O2 with the antibonding acceptor orbital, 90, for P1-H4 is 29.8 kJ/mol.

The interaction of the third lone pair donor orbital, 14, for O2 with the antibonding acceptor orbital, 91, for P1-H5 is 31.2 kJ/mol.

The interaction of the second lone pair donor orbital, 16, for O3 with the antibonding acceptor orbital, 90, for P1-H4 is 81.5 kJ/mol.

The interaction of the second lone pair donor orbital, 16, for O3 with the antibonding acceptor orbital, 91, for P1-H5 is 82.1 kJ/mol.

The interaction of the third lone pair donor orbital, 17, for O3 with the antibonding acceptor orbital, 88, for P1-O2 is 106. kJ/mol.

The interaction of the third lone pair donor orbital, 17, for O3 with the antibonding acceptor orbital, 90, for P1-H4 is 30.9 kJ/mol.

The interaction of the third lone pair donor orbital, 17, for O3 with the antibonding acceptor orbital, 91, for P1-H5 is 30.1 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.

21 ----- 7.619

20 ----- 6.728
19 ----- 6.500
18 ----- 5.902

17 -^-v- -0.440

16 -^-v- -0.735

15 -^-v- -0.944

14 -^-v- -1.191

13 -^-v- -3.350

12 -^-v- -4.114

11 -^-v- -4.991

10 -^-v- -8.419

9 -^-v- -16.80

8 -^-v- -18.23

7 -^-v- -118.8
6 -^-v- -118.8
5 -^-v- -118.9

4 -^-v- -166.4

3 -^-v- -499.3 2 -^-v- -499.3

1 -^-v- -2064.

## 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 = -493.1921859244 Hartrees