Quantum-Chemical Design of Host Materials for Full-Color Triplet Emission

Ab‐initio calculations have been used to show, via a rigorous treatment of molecular topology and substitution effects, that the position of frontier molecular orbitals (MOs) and the singlet–triplet energy gap in carbazole‐spiro derivatives can be tuned almost independently, thus providing a way to insure efficient charge injection while maintaining a high‐energy triplet state.