Room-Temperature phosphorescent materials constructed based on Cucurbit[8]uril for encryption and anti-counterfeiting

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Photophysics

Background:

• Room temperature phosphorescence (RTP) is crucial for advanced optical applications.
• Developing stable and efficient RTP materials remains a challenge.
• Supramolecular assemblies offer tunable photophysical properties.

Purpose of the Study:

• To construct a supramolecular assembly for enhanced room temperature phosphorescence.
• To investigate the photophysical properties of the assembly.
• To explore applications in information encryption and anti-counterfeiting.

Main Methods:

• Construction of a supramolecular assembly using cucurbit[8]uril (Q[8]) and a 6-bromoisoquinoline derivative (BI-BOH).
• Formation of a 1:2 Q[8]-BI-BOH assembly, strengthening intersystem crossing (ISC).
• Fabrication of Q[8]-BI-BOH/polyvinyl alcohol (PVA) films and incorporation of fluorescent dyes as energy acceptors.

Main Results:

• The Q[8]-BI-BOH assembly exhibited a low energy gap (ΔE_ST = 0.03 eV), enhancing ISC.
• The resulting films displayed long-lived room temperature phosphorescence (τ = 0.128 s) due to inhibited non-radiative transitions.
• Energy transfer with added dyes allowed for adjustable afterglow colors.

Conclusions:

• The supramolecular assembly effectively promotes RTP through host-guest interactions and ISC.
• The tunable phosphorescence of the material is suitable for information encryption and anti-counterfeiting.
• This work expands the application scope of luminescent materials.