Chemistry, Light and Dynamics Group Semianr

Tuning photophysical properties, such as energies and oscillator strengths, of molecules is a crucial task in current chemistry. The standard toolbox – variations in delocalisation, electron donating/withdrawing substituents, and changes in the HOMO/LUMO overlap – is quite limited and often not sufficient to reach the desired properties. This talk will explore a recently emerging alternative design route, the exploitation of excited-state aromaticity.  

 I will start by explaining excited-state aromaticity within the molecular orbital picture^[1] before introducing a new method for the visualisation of chemical shielding tensors (VIST)^[2] based on the nucleus[1]-independent chemical shift. This toolbox will be used to study the properties of biphenylene derivatives explaining dramatic differences in excitation energies between isomeric structures.^[1] Subsequently, the photo-redox properties of macrocycles with formally antiaromatic ground states will be discussed. ^[3,4] 

References 

[1]          F. Plasser, Chemistry 2021, 3, 532–549.  

[2]          F. Plasser, F. Glöcklhofer, European J. Org. Chem. 2021, 2021, 2529–2539.  

[3]          M. Pletzer, F. Plasser, M. Rimmele, M. Heeney, F. Glöcklhofer, Open Res. Eur. 2021, 1, 111.  

[4]          M. Rimmele, W. Nogala, M. Seif-Eddine, M. M. Roessler, M. Heeney, F. Plasser, F. Glöcklhofer, Org. Chem. Front. 2021, 8, 4730–4745.