Synthesis and properties of the conjugated polymers with indenoindene and benzimidazole units for organic photovoltaics

Abstract

A new electron deficient unit, dimethyl‐2H‐benzimidazole (MBI), and dihydroindeno[2,1‐a]indene (ININE) moiety as electron‐rich unit were coupled to synthesize the conjugated polymers containing electron donor–acceptor pair for organic photovoltaics. ININE, MBI, and thiophene (or bithiophene) units were incorporated using Stille and Suzuki polymerization to generate poly(2,7‐(5,5,10,10‐tetrakis(2‐ethylhexyl)‐5,10‐dihydro‐ indeno[2,1‐a]indene)‐alt‐5,5‐(4′,7′‐di‐2‐thienyl‐2,2‐dimethyl‐2H‐benzimidazole)) (PININEDTMBIs) (or PININEBBTMBIs). In MBI, the sulfur at 2‐position of 2,1,3‐benzothiadiazole (BT) unit was replaced with dialkyl‐substituted carbon, whereas keeping the 1,2‐quinoid form, to improve the solubility of the polymers. The field‐effect hole mobility of PININEBBTMBI was 3.2 × 10−4 cm2/Vs which was improved as compared to that of PININEDTMBI (2.7 × 10−5 cm2/Vs) caused by the introduction of bithiophene units. In case of the most efficient polymer, PININEBBTMBI, the device with the configuration of indium tin oxide (ITO)/poly(3,4‐ethylenedioxythiophene) (PEDOT):polystyrene sulfonate (PSS)/polymer:PC71BM(1:4 w/w)/Al, annealed at 100 °C for 10 min demonstrated a open circuit voltage of 0.78 V, a short‐circuit current density of 6.66 mA/cm2, and a fill factor of 0.41, leading to the power conversion efficiency of 2.11%, under white‐light illumination (AM 1.5 G, 100 mW/cm2). © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013

A Straightforward Synthesis of Chlorine‐Bearing Donor–Acceptor Alternating Copolymers with Deep Frontier Orbital Levels

“…1,2‐Bis(3‐(octyloxy)phenyl)ethane‐1,2‐dione, 5,8‐bis(5‐bromo­thiophen‐2‐yl)‐2,3‐bis(3‐(octyloxy)phenyl)quinoxaline, 4,5‐di­fluorobenzene‐1,2‐diamine,[11B] 2,5‐bistrimethyltinthiophene, and 5,5′‐bis(trimethylstannyl)‐2,2′‐bithiophene were prepared according to the literature. All the synthetic routes of the monomers and copolymers are shown in Scheme .…”

Syntheses and Properties of Conjugated Polymer with Thiophene‐Bridged BTI and Indenoindene Units for Organic Solar Cells

“…To the mixture of aqueous solution of 2 M K 2 CO 3 and toluene, Pd(PPh 3 ) 4 (3 mol%), 4,4,5,5‐tetramethyl‐2‐[5,5,10,10‐tetrakis(2‐ethylhexyl)‐7‐(4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)‐4 b ,5,9 b ,10‐tetrahydroindeno[2,1‐ a ]inden‐2‐yl]‐1,3,2‐dioxaborolane ( 4 ) (300 mg, 0.33 mmol), and N ‐(2‐dodecyl)‐5‐5′dibromo‐2,2′‐bithiophene‐3,3′‐dicarboximide ( 2 ) (223 mg, 0.33 mmol) were added. After 72 h of reflux under the atmosphere of Ar, phenylboronic acid was added to the mixture of the reaction.…”

Recent Developments in the Suzuki-Miyaura Reaction: 2010–2014

“…Interestingly, almost all polymers in this list were prepared using Pd(PPh 3 ) 4 or Pd(OAc) 2 as catalysts [164,165,166,167,168,169,170,171,172], although there are some exceptions [173,174,175,176,177,178]. Focussing more in the catalyst employed and carrying out a catalyst screening for a specific polymerization is gradually becoming more and more common [139,140,141,142,143,144,145,146,147,148,149,150,179,180,181].…”