Through-space conjugation engineering in methylated tetraphenylethene derivatives

This work reports methylated tetraphenylethene derivatives exhibiting systematically enhanced and blue-shifted emission due to increased methylation-induced steric hindrance and reduced through-space conjugation (TSC). Temperature-dependent photophysical studies show that the TSC strength varies with temperature, weakening at cryogenic temperatures and causing emission blue-shifts. These insights advance the mechanistic understanding of TSC in rigid fluorophores, providing foundational principles for the rational design of tunable TSC-based luminescent materials.