Achieving Dual RTP/TADF Emission in a Bromine-Free 3D Ag(I) Coordination Polymer for High-Efficiency Exciton...

Area of Science:

• Materials Science
• Photochemistry
• Supramolecular Chemistry

Background:

• Simultaneous room-temperature phosphorescence (RTP) and thermally activated delayed fluorescence (TADF) in one material is challenging due to competing intersystem crossing (ISC) and reverse intersystem crossing (RISC).
• Silver(I) coordination polymers (CPs) are explored for their luminescent properties.

Purpose of the Study:

• To design and synthesize novel Ag(I) CPs exhibiting dual RTP and TADF emission.
• To investigate the structural and photophysical properties of these CPs.
• To explore potential applications in sensing and 3D printing.

Main Methods:

• Synthesis of two Ag(I) coordination polymers: a 3D framework [Ag2(BT)(NO3)2]n (CP1) and a 1D chain [Ag2(DBBT)2(NO3)2]n (CP2).
• Structural characterization using X-ray diffraction.
• Photophysical studies including photoluminescence quantum yield (PLQY) measurements and analysis of emission mechanisms (RTP and TADF).

Main Results:

• CP1, a bromine-free 3D framework, exhibited dual RTP/TADF emission with a high PLQY of 33.6%.
• CP2, a brominated 1D chain, showed only RTP with a low PLQY of 3.7%.
• The rigid 3D structure and absence of heavy atoms in CP1 were crucial for facilitating both ISC and RISC, enabling efficient exciton utilization.

Conclusions:

• A bromine-free structural design strategy successfully achieved synergistic RTP and TADF emissions in Ag(I) CPs.
• CP1 demonstrates potential as a temperature-sensitive sensor and a stable luminescent ink for 3D printing.
• The findings provide insights into controlling photophysical properties in CPs through structural design.