Stable radical anions generated from a porous perylenediimide metal-organic framework for boosting near-infrared photothermal conversion

Baozhong Lü,Pengyu Li,Meizhen Yin,Yifa Chen,Bo Wang,Klaus Müllen

doi:10.1038/s41467-019-08434-4

Abstract

Radical anions of electron-deficient systems are widely used, but are easily reoxidized upon exposure to air. Therefore, the stabilization of radical anions under ambient conditions is of great significance, but still remains a scientific challenge. Herein, perylenediimide is employed to prepare a crystalline metal-organic framework for stabilizing radical anions without extensive chemical modification. The porous, three-dimensional framework of perylenediimide can trap electron donors such as amine vapors and produce radical anions in-situ through photo-induced electron transfer. The radical anions are protected against quenching by shielding effect in air and remain unobstructed in air for at least a month. Because of the high yield and stability of the radical anions, which are the basis for near-infrared photothermal conversion, the framework shows high near-infrared photothermal conversion efficiency (η = 52.3%). The work provides an efficient and simple method towards ambient stable radical anions and affords a promising material for photothermal therapy.

Highlights

Radical anions of electron-deficient systems are widely used, but are reoxidized upon exposure to air
Because of the deep penetration ability and dark field viewing properties of NIR light, the NIR photothermal effect has been of interest in applications such as NIR photothermal ablation[3], NIR laser-assisted photothermal therapy[4], and night vision sensors[5]
We report a PDI-based 3D Metal-organic frameworks (MOFs), Zr-PDI, composed of a N,N′-di-(4-benzoic acid)-1,2,6,7-tetrachloroperylene-3,4,9,10-tetracarboxylic acid diimide (P-2COOH) ligand and Zr6(μ3-O)4(μ3-OH)[4] clusters (Fig. 1)

Summary

Introduction

Radical anions of electron-deficient systems are widely used, but are reoxidized upon exposure to air. Functionalized PDI materials without extensive chemical modification, but yielding stable RAs under ambient conditions, would be highly desirable. Optical properties and formation of RAs. The arrangement of P-2COOH molecules within the framework makes it a remarkable model to study the optical properties of Zr-PDI (Supplementary Figs 8–12).

Results

Conclusion