SIGN OF CIRCULAR-DICHROISM INDUCED BY BETA-CYCLODEXTRIN

On the basis of the coupled oscillator theory, the circular dichroism induced by beta-cyclodextrin (beta-CDx) is calculated. It is revealed from the calculation that outside the cavity of beta-CDx the sign of the induced circular dichroism (ICD) becomes opposite to that inside it; namely, outside the cavity of beta-CDx an electric transition polarized along the axis of the cavity gives negative ICD while a transition polarized normal to it affords positive ICD. The present rule is supported qualitatively in view of the dipole-dipole interaction between a transition moment of a chromophore and an individual bond in beta-CDx.