Multifunctional electroluminescence materials with aggregation-induced emission properties and reversible mechanoluminescence

Abstract

Herein, the design and synthesis of blue luminogens (t-BuTPAniq and t-BuTPA2niq) were reported, which employed 4-(tert-butyl)-N-(4-(tert-butyl)(5-phenyl)-N-phenylaniline (t-BuTPA) as the electron donor (D) and isoquinoline (iq) as the electron acceptor (A), linking via naphthalene π-bridges. In toluene solution, t-BuTPAniq and t-BuTPA2niq exhibited emission wavelengths (λ_max) of 462 nm and 454 nm, with photoluminescent quantum yields (PLQY) of 34 % and 38 %, respectively. Notably, t-BuTPAniq presented a PLQY of 71 % and t-BuTPA2niq showed a PLQY of 79 % in neat film, indicating that these two complexes might display aggregation-induced emission (AIE) characteristics. In dichloromethane solution, the photoluminescence lifetimes of t-BuTPAniq and t-BuTPA2niq were 61.9 ns and 67.9 ns at room temperature, respectively. Futhermore, the experiments proved that these molecules possessed distinct AIE characteristics and reversible mechanical chromic properties. Their notable acid-base color-changing capabilities were advantageous for applications in fluorescence anti-counterfeiting. Organic light-emitting devices (OLEDs) fabricated with t-BuTPAniq and t-BuTPA2niq exhibited blue electroluminescence with emission peaks at 472 nm, achieving maximum external quantum efficiencies (EQEs) of 4.0 % and 3.6 %, respectively. In summary, these molecules presented a novel research direction for developing multifunctional blue electroluminescent materials, indicating significant potential for applications in displays, lighting technologies, and fluorescence anti-counterfeiting.