Synergistic effects of triplet–triplet annihilation and reverse intersystem crossing in a platinum-based electrochemiluminescent metallopolymer emitter
Journal
Journal of Materials Chemistry C
Journal Volume
13
Journal Issue
17
Start Page
8671
End Page
8681
ISSN
2050-7526
2050-7534
Date Issued
2025-03-05
Author(s)
Chun Hong Mak
Yaojia Ai
Chunyan Tan
Wenxin Niu
Chang-Wei Hsieh
Hsin-Hui Shen
Zheng Hu
Yanqing Tian
Xueqing Xu
Guizheng Zou
Duu-Jong Lee
Hsien-Yi Hsu
DOI
10.1039/d4tc05445h
Abstract
This work presents the synthesis, electrochemical behavior, and photophysical properties of a novel platinum acetylide metallopolymer (p-PtBTD), designed for enhanced electrogenerated chemiluminescence (ECL) performance. The metallopolymer features alternating π-conjugated segments of 2,1,3-benzothiadiazole (BTD) and trans-Pt(PBu3)2 units. The inclusion of platinum centers facilitates efficient intersystem crossing (ISC), allowing the radiative decay of triplet excitons, which is typically challenging in conventional ECL systems dominated by singlet emission. Photoluminescence (PL) studies reveal dual emission, with a prominent fluorescence peak at 584 nm and a weak phosphorescence peak near 800 nm. Electrochemical investigations demonstrate quasi-reversible oxidation and irreversible reduction waves for p-PtBTD, while transient ECL studies reveal instability in the radical cation, which has been successfully addressed using tripropylamine (TPrA) as a co-reactant. The ECL spectrum shows dual emission arising from both singlet and triplet states, facilitated by triplet-triplet annihilation (TTA) and reverse intersystem crossing (RISC) due to a small energy gap (∼0.5 eV) between these states. This dual emission mechanism, involving both fluorescence and phosphorescence, highlights the potential of p-PtBTD for advanced ECL applications, particularly in sensing and optoelectronics. These findings underscore the utility of metallopolymers in overcoming the limitations of traditional ECL systems, paving the way for more efficient and versatile luminescent materials.
Publisher
Royal Society of Chemistry (RSC)
Type
journal article