Circular dichroism measurements in the VUV

Abstract

The extension of circular dichroism measurements into the VUV region was motivated by the need to provide supplementary techniques to the absorption studies lacking rotational and vibrational structure. CD as one of these techniques is determined by selection rules which differ from those in absorption and thus enables the assignment of excited electronic states. Another application of VUVCD measurements is the use of correlation between the sign of the CD signal and the absolute configuration to formulate sector rules of chromophores absorbing only in the VUV. In this review we will present results obtained on our home-made instrument capable of measuring CD signal down to 150 nm. These applications of VUVCD will be demonstrated in systems such as the oxirane chromophore, the methylenecyclohexene chromophore and the amine chromophore. The role of singlet-triplet transitions and their contribution to CD and ORD will also be discussed.