A modular approach to tuning the charge transfer properties of photoluminescent quinine analogues.

We have shown that Pd-catalysed cascade processes provide molecular access to rigid quinoline-containing tetracylic amines. This enables fine-tuning of the through-space charge transfer (TSCT) state formation by variation of both N-aryl distance and quinoline substitution. It was observed that decreasing the N-aryl distance enhanced the formation of the TSCT species giving control over emission colour and photoluminescence quantum yield. Methoxylation of the quinoline unit decreases the propensity of TSCT formation. This systematic study provides great insight for TSCT formation with impact on further understanding dimeric, excimeric and exciplex species.