Substituent effects on opticalproperties of pyrrolizine-fused BOPYIN

Debao Liu; Liu Wen; Xi Chen; Jiaying Yan; Kaibo Zheng; Xiang Liu; Yuanyuan Hu; Nuonuo Zhang

doi:10.1016/j.saa.2021.119681

Substituent effects on opticalproperties of pyrrolizine-fused BOPYIN

Spectrochim Acta A Mol Biomol Spectrosc. 2021 Jun 5:254:119681. doi: 10.1016/j.saa.2021.119681. Epub 2021 Mar 10.

Authors

Debao Liu¹, Liu Wen¹, Xi Chen¹, Jiaying Yan¹, Kaibo Zheng¹, Xiang Liu¹, Yuanyuan Hu², Nuonuo Zhang³

Affiliations

¹ College of Materials and Chemical Engineering, Medical College, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, China; Three Gorges University, Yichang, Hubei 443002, China.
² College of Materials and Chemical Engineering, Medical College, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, China; Three Gorges University, Yichang, Hubei 443002, China. Electronic address: ponyhoo@gmail.com.
³ College of Materials and Chemical Engineering, Medical College, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, China; Three Gorges University, Yichang, Hubei 443002, China. Electronic address: nnzhang2015@ctgu.edu.cn.

PMID: 33744704
DOI: 10.1016/j.saa.2021.119681

Abstract

Three new pyrrolizine-fused BOPYINs (DAB-H, DAB-OMe, DAB-ester) have been reported in 26-35% yield. The relationship between structures and optical spectra was investigated, which all the compounds show large Stokes Shift (3146-3884 cm^-1) and high quantum yield (up to 99%) in solvents. Among these dyes, the decoration of electron donating/withdrawing groups on indole, pyrrole and pyrrolizine units has a significant impact on optical properties, especially emission spectra. The results suggested that electron withdrawing group on pyrrole and pyrrolizine units has hypsochromic shift on emission spectra (DAB-H, DAB-OMe, DAB-ester versus DAB-1,4,5). The optimized structure, electron distribution on frontier molecular orbital, energy gap and simulated stick spectra of DABs are discussed by Density Functional Theory (DFT) calculation. We claim the agreement between the experimental and theoretical absorption spectra.

Keywords: BOPYIN; Diazaborepin; Pyrrolizine; Seven-membered ring; Unsymmetric BF(2) chromophore.