Intertek ASG Laboratory, Manchester, UK > Computational Chemistry Group > Physical Property Prediction

Physical Property Prediction

Fast predictive methods based on extensive databases of literature values can be applied to generate a wide range of physical chemical properties. Predictions can be run individually for single molecules or in batch mode to enable screening across chemical libraries. Properties available include:

• pKa's
• logP
• logD

• Aqueous Solubility
• Other Properties

Looking for Physical Property Measurements? Please visit:

• Intertek ASG Physical Property Measurements
• Global Intertek Physical Property Testing

pKa:

• pKa is the acid-base ionisation constant
• It indicates whether a molecule or ion is likely to keep a proton at its ionisation centre(s)
• It is available for a wide range of organic compounds
• Predicted accuracy is usually better than +/- 0.5 pKa units
• The software's internal database contains values for >16,000 structures

logP:

• logP is the octanol-water partition coefficient
• It indicates whether a neutral molecule will prefer an aqueous or orgainic phase
• Predicted accuracy is usually better than +/- 0.3 logP units
• The software's internal database contains values for >18,000 structures

logD:

• logD is the octanol-water distribution coefficient
• It is a combination of pKa and logP
• It produces an apparent partition coefficient for any pH value
• The overall value can be broken down into a per species contribution

Aqueous Solubility:

• Determine the aqueous solubility of organic compounds for pH values from 0 to 14
• Predicted accuracy, even for complex structures, is usually better than +/- 0.5 logS units
• The software's internal database contains values for >5000 structures
• Useful in applications requiring purification by recrystallisation or in biomedical uptake
• Important for studies of pharmaceutical oral absorption and toxicity of chemical compounds

Other Properties

In addition to the four most common physical properties detailed above, many other properties can be calculated or experimental values can be retreived from databases. These include:

• Bioconcentration Factor (BCF)
• Boiling Point
• Critical Pressure
• Critical Temperature
• Critical Volume
• Density
• Dielectric Constant
• Dipole Moment
• Gibbs Energy
• Hammett Sigma
• Hansen (3D) Solubility Parameters
• Heat of Formation
• Henry's Law Constant

• HLB (Hydrophilic Lipophilic Balance)
• Hydrophilic Surface Area
• Index of Refraction
• Liquid Viscosity
• Melting Point
• Molar Volume
• Molar Refraction
• Organic Carbon Adsorption Coefficient (Koc)
• Parachor
• Polarisability
• Solubility Parameter
• Surface Tension
• Vapour Pressure