solvophobicity parameter, Sp

A solvent parameter defined by:
Sp = 1 − M M hexadecane
derived from the Gibbs energy of transfer (Δ t G °) of a series of solutes from water to numerous aqueous-organic mixtures and to pure solvents:
Δ t G ° to solvent = M R T + D
where R T is a solute parameter, and M and D characterize the solvent. The M values are used to define a solvent solvophobic effect so that S p values are scaled from unity (water) to zero (hexadecane).
Source:
PAC, 1994, 66, 1077 (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1165