Electron density effect of aromatic carboxylic acids in naphthalenediimide-based coordination polymers: from thermal electron transfer and charge transfer to photoinduced electron transfer
Gao‐Peng Li, Jing Zhang, Wan-Wan Ren, Si-Nan Wang, Yingxia Wang, Yingxia Wang, Yunlong Fu, Yao‐Yu Wang, Yao‐Yu Wang
Abstract
IPA-OH = 5-hydroxyisophthalic acid). UV-vis and EPR spectroscopy and DFT calculations analyses reveal that the occurrence of themal electron transfer (TET) in 1 and 2 results from the HOMO of the IPA and IPA-OH lying higher than the LUMO of the NDI. Meanwhile, compared to 1, the UV-vis absorption spectrum of 2 exhibits a significant red shift, which suggests higher electron density of the donor and more electron transfer pathways are beneficial for the occurrence of intermolecular CT. After UV light irradiation, the comparison of the photochromic behavior of 1 and 2 confirms the negative effect of the stronger CT on photoinduced electron transfer (PET). The present study illustrates the delicate modulating effect of electron density on the CT and ET behaviors in D-A CPs.