Acta Chimica Sinica ›› 2025, Vol. 83 ›› Issue (11): 1356-1362.DOI: 10.6023/A25050166 Previous Articles     Next Articles

Article

N-取代基对萘二酰亚胺基配位聚合物光致变色性能的调控作用

张士民a, 郝朋飞b,*(), 于炜玉b, 朱慧慧b, 杨海英a, 沈俊菊b, 付云龙b,*()   

  1. a 运城学院应用化学系 运城 044000
    b 山西师范大学化学与材料科学学院 太原 030031
  • 投稿日期:2025-05-14 发布日期:2025-06-27
  • 通讯作者: 郝朋飞, 付云龙
  • 基金资助:
    国家自然科学基金(21171110); 山西省科技厅项目(20210302123324); 山西省科技厅项目(201901D111275)

The Modulation Effect of N-Substituents on Photochromic Properties of Naphthalenediimide-based Coordination Polymers

Zhang Shimina, Hao Pengfeib,*(), Yu Weiyub, Zhu Huihuib, Yang Haiyinga, Shen Junjub, Fu Yunlongb,*()   

  1. a Department of Applied Chemistry, Yuncheng University, Yuncheng 044000, China
    b School of Chemical and Material Science, Shanxi Normal University, Taiyuan 030031, China
  • Received:2025-05-14 Published:2025-06-27
  • Contact: Hao Pengfei, Fu Yunlong
  • Supported by:
    National Natural Science Foundation of China(21171110); Natural Science Foundation of Science and Technology Agency of Shanxi Province(20210302123324); Natural Science Foundation of Science and Technology Agency of Shanxi Province(201901D111275)

In recent years, although the photochromic properties of photochromic coordination polymers (PCCPs) has been greatly improved, the regulation of photochromic performance still face tremendous challenges. Here, two photoresponsive 1,4,5,8-naphthalenediimide (NDI)-based coordination polymers (CPs), [Cd(3-DPNDI)(1,4-HNDA)(FA)]•DMF (1) and [Cd(3-PANDI)2(1,4-HNDA)2]•2DMF•2H2O (2) (FA=formate, DMF=dimethyl formamide), have been designed (based on modulation effect of N-substituents) and obtained by assembly of N,N'-bis-(3-pyridyl)-1,4,5,8-naphthalenediimide (3-DPNDI)/N,N'-bis-(3-pyridinamide)-1,4,5,8-naphthalenediimide (3-PANDI), 1,4-naphthalene dicarboxylic acid (1,4-H2NDA) and cadmium nitrate tetrahydrate (Cd(NO3)2•4H2O), respectively. The structures and photochromic properties of 1 and 2 have been detailedly investigated by single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), thermogravimetry (TGA), Fourier transform infrared (FT-IR) spectra, UV-Vis absorption spectroscopy (UV-vis), kinetics curves and electron paramagnetic resonance (EPR). Interestingly, although 1 and 2 have the same two-dimension (2D) framework, they exhibit completely different photochromic behaviors. Upon exposure to ca. 365 nm Hg lamp, 1 displays a prominent color change from yellow to brown within 5 s, while 2 shows a color transformation from orange to brown within 15 s, both of which saturation time is 30 min. This phenomenon indicates that 1 has more excellent photochromic properties compared with 2. To investigate the reason, the interface relationship was analyzed carefully. Although 2 has a shorter electron transfer pathway (lone pair-π interactions: 0.3471 nm and 0.3650 nm in 1 vs. 0.3113 nm and 0.3375 nm in 2; π-π interactions: 0.3678 nm, 0.3741 nm and 0.3758 nm in 1 vs. 0.3550 nm and 0.3725 nm in 2), the photochromic performance of 1 is superior to that of 2, which is mainly ascribed to the stronger charge transfer (CT) in 2 leading to the decrease of electron-accepting ability of electron acceptors and thereby inhibits the electron transfer (ET) process. This study demonstrates the subtle modulating effect of N-substituents on the interfacial relationship between electron donors and electon acceptors, intermolecular CT, photoinduced intermolecular ET and photochromic properties, which provides a new idea for the devel- opment of coordination polymers with controllable photochromic properties. Meanwhile, this work provides an effective strategy for the regulation of photochromic properties

Key words: 1,4,5,8-naphthalenediimide, coordination polymers, photochromic property, electron transfer, charge transfer