|
|
|
|
| DZV model of 1,3-Dichlorobenzene. |
The DZV model of 1,3-Dichlorobenzene was found to be the
best geometry to show the characteristics of
1,3-Dichlorobenzene. It was found to be the best model
because it gave the best results for the calculations of
certain properties for the molecule.
Bond Lengths
Bond Lengths
| Atoms |
621-G |
631-G |
DZV |
| C-H |
0.107 nm |
0.107 nm |
0.107 nm |
| C-C |
0.138 nm |
0.138 nm |
0.139 nm |
| C-Cl |
0.181 nm |
0.181 nm |
0.180 nm |
|
|
|
||
| HOMO model of 1,3-Dichlorobenzene. |
The HOMO orbitals are the highest
energy molecular orbitals that are occupied by
electrons. For 1,3-Dichlorobenze, the HOMO orbitals are
non-bonding. Knowing the characteristics of the HOMO
orbitals will help predict how the molecule will react.
|
|
|
|
| LUMO model of 1,3-Dichlorobenzene. |
The LUMO orbitals are the lowest
energy molecular orbitals that are occupied by
electrons. For 1,3-Dichlorobenzene, it appears that the
LUMO orbitals are also no-bonding. As stated for HOMO
orbitals, know the characteristics for LUMO orbitals
will help predict how the molecule will react.
|
|
|
|
| Insert a caption for Electrostatic potential model of 1,3-diclbenz here. |
The electrostatic model for
1,3-Dichlorobenze is as predicted, there is a large
electron cloud around the chloride atoms. It is expected
that the chloride atoms would be surrounded by a large
electron cloud because they have a greater number of
valence electrons than carbon or hydrogen.
Dipole Moment
The calculated dipole moment for 1,3-Dichlorobenzene was found to be 2.503920 Debye.
UV-Vis Absorption Peak Positions.
It was not possible to obtain an UV-Vis spectrum for 1,3-Dichlorobenzene, but there are calculations that predict where peaks would occur on an UV-Vis spectrum for 1,3-Dichlorobenzene.
The calculated dipole moment for 1,3-Dichlorobenzene was found to be 2.503920 Debye.
UV-Vis Absorption Peak Positions.
It was not possible to obtain an UV-Vis spectrum for 1,3-Dichlorobenzene, but there are calculations that predict where peaks would occur on an UV-Vis spectrum for 1,3-Dichlorobenzene.
| Excitation Energy (1/cm) |
Oscillator Strength |
|
| Ground State to Energy Level: 1 |
50,396.65 |
0.001913 |
| 2 |
52,105.52 |
0.003603 |
| 3 |
60,289.16 |
0.0000140 |
| 4 |
62,145.54 |
0.003440 |
| 5 |
66,234.25 |
1.474599 |
| 6 |
66,769.80 |
1.156795 |
| 7 |
72,536.21 |
0.011329 |
| 8 |
73,153.24 |
0.008567 |
| 9 |
74,877.94 |
0.000392 |
| 10 |
76,300.88 |
0.000048 |
| 11 |
78,141.71 |
0.001195 |
According to the table above, it seems that there
are only two absorption peaks that would be
noticeable. This is because the oscillator strength
for the transition from ground state to energy
levels 5 and 6 is so much greater than that of other
transitions. The next highest oscillator strength is
that of the transition from ground state to energy
level 7, and that is weaker by a factor of 100. So
the other peaks just wouldn't be as prominent than
the the two strong peaks, and there would be two
peaks located at 66,234.25 and 66,769.80 1/cm.
IR Spectrum
The IR spectrum for 1,3-dichlorobenzene has two
areas where is seems that some peaks were
removed. The two areas that were removed would
have shown some peaks due to the double bonded
carbon to carbon bond in the aromatic ring at
around 1680-1600 1/cm. The other area would have
shown a peak that would indicate the carbon to
chloride bond, which would have absorbed at
around 785-540 1/cm. Also if there was a peak
shown at around 800 1/cm, the 900, 800, and 700
1/cm peaks would have indicated that the
molecule was an meta-disubstituted aromatic
ring. The peak at around 900 1/cm is due to the
out of plane stretching between the aromatic
ring and a hydrogen atom.