Optical studies of pressure effects : III. Pressure effect on the aqueous solution of amylose-iodine complex

Abstract

The absorption spectrum of an aqueous solution of amylose-iodine complex was measured under high pressure up to 4000kg/cm^2. The absorption intensity at 620mμ decreases with increase of pressure and the intensity does not return to its initial value at normal pressure. It is not reasonable to regard this change as induced by the transition from helix to random-coil configuration of amylose molecules, judging from the result concerning the viscosity change and the pressure effect on the solution containing only amylose. It may be considered qualitatively that this change is due to the shift of the equilibrium between free I_2 and I_3 in the complex solution under high pressure.