Boiling Point Estimation by JAVA applet
Draw molecule at cyan panel. How to use animation1, animation2
Change atom type or delete atom, mouse down and up at the same atom.
Cis-, Trans- compounds return average
of both.
Hydrogen will be added automatically by program.
The boiling point is defined as the temperature
at which the vapor
pressure of a liquid is equal to the
pressure of the atmosphere on the liquid.
For pure compounds, the normal boiling point is defined as the boiling point
at one standard atmosphere of pressure on the liquid.
If the pressure on the liquid differs
from one atmosphere, the boiling point observed
for the compound differs from that estimated for the pure compound.
It can be said
- molecular size become larger, boiling point become larger.
- compare with spherical structure and stick type structure, spherical structure become lower boiling point. ( because of accessible surface area? )
- hydrogen bond make boiling point raise dramatically
- Dipole moment(refer to CNDO or QEQ) make boiling point (maybe) raise
- Halogen atom make boiling point bring down
There are several methods to predict boiling point.
- Meissner
- Lydersen, Forman, Thodos, JOBACK
- Miller
- Ogata and Tsuchida
- Somayajulu and Palit
- Kinney
- Stiel and Thodos
These method need critical temperature ( Tc ) (critical pressure Pc ) information or need parachors. And can apply very limited compounds.
Our method is based on artificial Neural Network ( ANN ). You have to do is only write molecular structure on the screen. JAVA applet automatically analyze that structure and return boiling point. Our method can apply for carbon number 2-12 compounds which neither have Aromatic ring nor have halogen atoms. Aromatic compounds and halogenated compounds are available only for member or sponsor.
Boiling point is one of the best important thermal properties. Almost all other thermo chemical properties are predictable from boiling point and critical constants with using corresponding state theory. So precise forecast of boiling point is very needed. Impurities in the liquid, or mixed solvent boiling point will become different from normal boiling point. In this case, estimation of PVT ( pressure - volume - temperature ) relationship works effectively.
Related Properties Vapor Pressure and Reduced Pressure Boiling Point