Site-selective thionation and doping enabled tunable full-color emission in nonconventional luminophores

Abstract

Nonconventional luminophores have gained significant attention for their distinctive luminescence behaviors and promising applications. However, achieving precise control over their photoluminescence (PL) remains a substantial challenge. Current strategies for structural modification remain largely semi-empirical, lacking robust frameworks to effectively correlate molecular-level variations with aggregate states and their corresponding PL. In this study, we demonstrate tunable full-color emission (blue to red) with a high quantum yield of up to 58.9%, through site-selective thiolation of hydantoin (HA) and subsequent host–guest doping. We elucidate the thionation effect on both individual molecules and their molecular arrangements, revealing that CS groups and parallel molecular arrangement promote extensive electron delocalization and redshifted PL. Leveraging the structural and packing similarity between the host and guest, we achieve fine-tuning of PL by doping thionated molecules into HA and thiazolidinedione crystals, establishing a direct structure–property relationship without requiring complex molecular redesign. Furthermore, we showcase the applicability of these luminophores in advanced anti-counterfeiting, information encryption and high-resolution visualization of latent fingerprints. This research offers novel insights and broadly applicable strategies for achieving tunable emission in nonconventional luminophores by precisely controlling electronic structures and molecular arrangement.