A COMPARISON OF GAS-HEXADECANE AND GAS-APOLANE PARTITION-COEFFICIENTS

Gas-apolane partition coefficients (L-87) Of 157 nonpolar and polar or ganic solutes, spanning a wide range of functional groups, dipolaritie s, and hydrogen-bonding capabilities, are measured by open tubular cap illary gas chromatography at 40 degrees C. The experimental values com pare well (R-2 = 0.999) with literature values of log L-87 from packed -column gas chromatography, The log L-87 values are also compared with gas-hexadecane partition coefficients (log L-16) at 25 degrees C. A s trong linear relationship exists between log L-87 and log L-16 for all solutes (R-2 = 0.994), as well as for chemically relevant subsets of the data. Therefore, unknown L-16 values at 25 degrees C can be predic ted from the corresponding L-87 values, which can be measured on open- tubular or packed columns at higher temperatures, due to the low volat ility of apolane. Predicted values of L-16 would be extremely useful, since log L-16 is Often the major explanatory parameter in many linear solvation energy relationships.