Gas chromatographic study of the hydrogen bonding of aliphatic alcohols to tri-n-octylphosphine oxide

Retention volumes of 21 aliphatic alcohols were measured at five temperatures between 30 and 60°C in columns packed with different percentages of squalane or with solutions of tri-n-octylphosphine oxide (TOPO) in squalane coated on previously deactivated Chromosorb W. Experimental data fit to a 1:1 alcohol–TOPO association model, with association constants ranging from 26 to 59 dm3 mol−1 at 45°C. Association constants follow the trend primary alcohols>secondary alcohols>tertiary alcohols, with minor differences between the members of each of these three groups. The association enthalpy for the 21 alcohols averages −21.8 kJ mol−1, with a standard deviation of −1.3 kJ mol−1