BODIPY-Based Donor–Acceptor π-Conjugated Alternating Copolymers

• Published in: Macromolecules 2011-06, Vol.44 (12), p.4767-4776
• Main Authors: Popere, Bhooshan C, Della Pelle, Andrea M, Thayumanavan, S
• Format: Article
• Language: English
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Polymers with particular properties; Preparation, kinetics, thermodynamics, mechanism and catalysts; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Transistors
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma200839q

Four novel π-conjugated copolymers incorporating 4,4-difluoro-4-borata-3a-azonia-4a-aza-s-indacene (BODIPY) core as the “donor” and quinoxaline (Qx), 2,1,3-benzothiadiazole (BzT), N,N ′-di(2′-ethyl)hexyl-3,4,7,8-naphthalenetetracarboxylic diimide (NDI), and N,N ′-di(2′-ethyl)hexyl-3,4,9,10-perylene tetracarboxylic diimide (PDI) as acceptors were designed and synthesized via Sonogashira polymerization. The polymers were characterized by 1H NMR spectroscopy, gel permeation chromatography (GPC), UV–vis absorption spectroscopy, and cyclic voltammetry. Density functional theory (DFT) calculations were performed on polymer repeat units, and the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energy levels were estimated from the optimized geometry using B3LYP functional and 6-311g(d,p) basis set. Copolymers with Qx and BzT possessed HOMO and LUMO energy levels comparable to those of BODIPY homopolymer, while PDI stabilized both HOMO and LUMO levels. Semiconductor behavior of these polymers was estimated in organic thin-film transistors (OTFT). While the homopolymer, Qx, and BzT-based copolymers showed only p-type semiconductor behavior, copolymers with PDI and NDI showed only n-type behavior.