Near-Infrared Emission Beyond 900 nm from Stable Radicals in Nonconjugated Poly(diphenylmethane)

Ziteng Zhang; Zuping Xiong; Jianyu Zhang; Bo Chu; Xiong Liu; Weihao Tu; Lei Wang; Jing Zhi Sun; Chengjian Zhang; Haoke Zhang; Xinghong Zhang; Ben Zhong Tang

doi:10.1002/anie.202403827

Near-Infrared Emission Beyond 900 nm from Stable Radicals in Nonconjugated Poly(diphenylmethane)

Angew Chem Int Ed Engl. 2024 Apr 8:e202403827. doi: 10.1002/anie.202403827. Online ahead of print.

Authors

Ziteng Zhang^{1

2

3

4}, Zuping Xiong^{1

3

4}, Jianyu Zhang⁵, Bo Chu^{1

2

3}, Xiong Liu^{1

2

3

4}, Weihao Tu^{1

3

4}, Lei Wang^{1

3

4}, Jing Zhi Sun^{1

3

6}, Chengjian Zhang^{1

2}, Haoke Zhang^{1

3

4

6}, Xinghong Zhang^{1

2}, Ben Zhong Tang^{1

5

7}

Affiliations

¹ Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China.
² State Key Laboratory of Motor Vehicle Biofuel Technology, International Research Center for X Polymers, Zhejiang University, Hangzhou, 310058, China.
³ MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Zhejiang University, Hangzhou, 310058, China.
⁴ Zhejiang-Israel Joint Laboratory of Self-Assembling Functional Materials, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China.
⁵ Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction and Institute for Advanced Study, The Hong Kong University of Science and Technology, Hong Kong, 999077, China.
⁶ Centre of Healthcare Materials, Shaoxing Institute, Zhejiang University, Shaoxing, 312000, China.
⁷ School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China.

PMID: 38589299
DOI: 10.1002/anie.202403827

Abstract

Organic radicals with narrow energy gaps are highly sought-after for the production of near-infrared (NIR) fluorophores. However, the current repertoire of developed organic radicals is notably limited, facing challenges related to stability and low fluorescence efficiency. This study addresses these limitations by achieving stable radicals in nonconjugated poly(diphenylmethane) (PDPM). Notably, PDPM exhibits a well-balanced structural flexibility and rigidity, resulting in a robust intra-/inter-chain through-space conjugation (TSC). The stable radicals within PDPM, coupled with strong TSC, yield a remarkable full-spectrum emission spanning from blue to NIR beyond 900 nm. This extensive tunability is achieved through careful adjustments of concentration and excitation wavelength. The findings highlight the efficacy of polymerization in stabilizing radicals and introduce a novel approach for developing nonconjugated NIR emitters based on triphenylmethane subunits.

Keywords: Near-infrared emission; Nonconjugated polymers; Radicals; Through-space conjugation.

Abstract

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