Tuning Transition Electric and Magnetic Dipole Moments: [7]Helicenes Showing Intense Circularly Polarized Luminescence

Deep-red circularly polarised luminescent C70 derivatives

“…Since the π-conjugated systems of both X70A and X70F are identical, the reason for the difference in the angles between the two types of moments can be attributed to the subtle electronic and steric effects of the substituents. In recent years, molecular design to control the angle and strength of the two transition moments has been studied intensively 49 , 50 .…”

Extended enantiopure ortho-phenylene ethylene (o-OPE)-based helical systems as scaffolds for supramolecular architectures: a study of chiroptical response and its connection to the CISS effect

“…That is, compounds can present high g abs values simply by diminishing |μ|. We hypothesize that conductive helical structures, which supposedly are ideal candidates for relevant CISS effect, must show a high |m|, higher than 1 x 10 -20 cgs units, 76 for transitions capturing the helical structure of the involved molecular orbitals. Moreover, CISS effect is directional and must be analyzed in the direction of electron transport, which is difficult using scalar quantities like g abs or rotational strength (R = (|μ||m|)cos(θ)).…”

Pathways to increase the dissymmetry in the interaction of chiral light and chiral molecules

“…In 2021, Matsuda and co-workers demonstrated an alternative approach to engineer the transition dipoles for helicenes, 49 where they introduced electron donating and withdrawing substituents into a [7]helicene framework in order to tune the frontier molecular orbitals. Judicious choice of the identity and placement of substituent groups allowed for an increase in | m |, while also rendering the transition partially symmetry-allowed.…”