Chiroptical properties of the ground and excited states of two thia-bridged triarylamine heterohelicenes

May 24, 2018

Title

Chiroptical properties of the ground and excited states of two thia-bridged triarylamine heterohelicenes

Author

Giovanna Longhi, Ettore Castiglioni, Claudio Villani, Rocchina Sabia, Stefano Menichetti, Caterina Viglianisi, Frank Devlin, Sergio Abbate

Year

2016

Journal

Journal of Photochemistry and Photobiology A: Chemistry

Abstract

Two thia-heterohelicenes of different length, namely a hetero [4]-helicene (1), and a hetero [6]-helicene (2) are studied by electronic circular dichroism (ECD), circularly polarized luminescence (CPL), vibrational circular dichroism (VCD) and optical rotation (OR). It is found that the ECD and VCD spectra are characteristically different from the corresponding spectra of the parent helicene molecules, indicative of the presence of hetero atoms. CPL spectra are discussed on the basis of DFT calculation results. The sign of the OR is different for the two thiaheterohelicenes and is correctly predicted by DFT calculations.

Instrument

J-815

Keywords

Circular dichroism, Circularly polarized luminescence