SOLUTE WATER INTERACTIONS IN THE ORGANIC-PHASE OF A BIPHASIC SYSTEM .2. EFFECTS OF ORGANIC-PHASE AND TEMPERATURE ON THE WATER-DRAGGING EFFECT

The ''water-dragging'' effect of various solutes was investigated in b iphasic systems made of water and poorly hydrated solvents, namely 6-u ndecanone, chloroform, and halothane. Like in the di-n-butylether/wate r system,1 the ''water-dragging'' effect is primarily determined by th e H-bond-donor acidity of solutes, while the chemical nature of the or ganic solvent (provided it is a poorly hydrated one) plays a limited r ole only. A molecular interpretation is offered whereby the predominan t influence of the H-bond-donor acidity of amphiprotic solutes (A) is due to their propensity to form cyclic hydrates of the type A2W and AW 2 (W = H2O).