Crystal structures, dual-state emissions and polymer-based doped room-temperature phosphorescence of 8-benzyloxyisoquinoline derivatives

Abstract

A series of new 8-benzyloxyisoquinoline derivatives are designed and synthesized based on the 4H-pyran chemistry. These compounds have twisted molecular conformations and loose packing modes according to their crystal structures, and thus exhibit outstanding dual-state emissions. Importantly, using cheap and easily available polymethyl methacrylate (PMMA) as the host molecule and the isoquinoline derivatives as the guest molecules, the resultant two-component doped materials show green or orange room-temperature phosphorescence (RTP) activities with delayed lifetimes of 72–106 ms, which originate from the guest molecule through the suppression of non-radiative transitions of excited triplet excitons by the rigid microenvironment provided by the PMMA polymer. This result provides a valuable reference for developing isoquinoline-based solid-state luminescent materials with dual-state emissions and RTP properties.