A series of novel BODIPY-fluorene copolymers: Synthesis, characterization, optical-electronic and nonlinear optical properties

Xiongjie Lin; Danting Tang; Tian He; Zheng Xu; Huayu Qiu; Qian Zhang; Shouchun Yin

doi:10.1016/j.saa.2019.03.084

A series of novel BODIPY-fluorene copolymers: Synthesis, characterization, optical-electronic and nonlinear optical properties

Spectrochim Acta A Mol Biomol Spectrosc. 2019 Jun 15:217:164-169. doi: 10.1016/j.saa.2019.03.084. Epub 2019 Mar 26.

Authors

Xiongjie Lin¹, Danting Tang¹, Tian He¹, Zheng Xu¹, Huayu Qiu¹, Qian Zhang², Shouchun Yin³

Affiliations

¹ College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 311121, PR China.
² College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 311121, PR China. Electronic address: qzhang@hznu.edu.cn.
³ College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 311121, PR China. Electronic address: yinsc@hznu.edu.cn.

PMID: 30933780
DOI: 10.1016/j.saa.2019.03.084

Abstract

A series of 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) with different connection sites and conjugation length and fluorene alternating conjugated polymers have been synthesized via palladium-catalyzed Suzuki coupling reaction. The polymers were fully characterized by ¹H NMR spectroscopy and gel permeation chromatography (GPC), and their properties were measured by thermogravimetric analysis (TGA), UV-vis absorption spectroscopy, cyclic voltammetry (CV), photoluminescence (PL) spectroscopy, the Z-scan technique, and theoretical calculation using density-functional theory (DFT) method. The results indicate that the connection sites and conjugation length of BODIPY have great effect on the optical-electronic and nonlinear optical properties of the conjugated BODIPY- fluorene copolymers although they don't affect the polymerization process. The absorption and emission peaks of P1 exhibit red shifts compared to those of P2 and P3. The polymers show good nonlinear optical properties that are closely related to the connection sites of the BODIPY pendants. P1 exhibits relatively richer nonlinear optical (NLO) properties than P2 and P3. The third order nonlinear optical coefficient (χ⁽³⁾) of P1 is 3.57 × 10^-11 esu, which is ~4 times larger than those of P2 and P3.

Keywords: BODIPY; Conjugated polymers; Fluorene; Nonlinear optical.