Cover Feature: Color Polymorphism and Room Temperature Phosphorescence of 4‐Bromo‐2,7‐Di‐Tert‐Butyl‐ 9‐Methoxypyrene (ChemPhysChem 18/2024)

Color polymorphism and the dissimilar photoluminescence spectra of two different crystals of 4-bromo-2,7-di-tert-butyl-9-methoxypyrene reflect the strong dependence of intermolecular interactions on the compound packing, which results in a significant change in electronic state energies and photophysics affected by the crystal structure. Lowering the first excited singlet state detunes it from the triplet manifold and reduces the intersystem crossing rate so that room-temperature phosphorescence is observed for one polymorph only. More information can be found in the Research Article by O. W. Morawski, J. Karpiuk and M. Morawski (DOI: 10.1002/cphc.202400457).