Craig plot

Craig plot showing values of Hansch pi and Hammett sigma constants for 26 common organic substituents

The Craig plot, named after Paul N. Craig, is a plot of two substituent parameters (e.g. Hansch-Fujita π constant and sigma constant) used in rational drug design.

Two most used forms of a Craig plot are

• plotting the sigma constants of the Hammett equation versus hydrophobicity
• plotting the steric terms of the Taft equation against hydrophobicity

See also

• Quantitative structure-activity relationship
• pKa

Further reading

• Craig, Paul N. (1971). "Interdependence between physical parameters and selection of substituent groups for correlation studies". Journal of Medicinal Chemistry. 14 (8): 680–684. doi:10.1021/jm00290a004. PMID 5114063.