Macroscopic Assembly of Chiral Hydrogen-bonded Metal-free Supramolecular Glasses for Enhanced Color-tunable Ultralong Room Temperature Phosphorescence

Abstract

Glassy materials, with desirable mechanical rigidity, shaping ability, high transparency, are attracting great interest in diverse fields. However, optically bulk molecule-based glasses are still rare, mainly due to limited monomeric species and harsh preparation conditions. Herein, we report a facile bottom-up solution fabrication process to obtain metal-free supramolecular glasses (SMGs) at the macroscopic scale using L-Histidine and hexamethylenetetramine as building blocks. The chiral SMGs possess color-tunable ultralong room temperature phosphorescence (decay lifetime up to 141.2 ms) and circular polarized luminescence (g factor up to 8.7×10−3). The strong hydrogen bonds effectively drive the formation of SMGs, and provide a rigid microenvironment to boost triplet exciton generation. By virtue of excitation- and temperature-dependent ultralong phosphorescence of the SMGs, applications including multicolored displays, visual UV detection, and persistently luminescent thermometer are demonstrated.