19201-53-7Relevant articles and documents
Exploiting excited-state aromaticity to design highly stable singlet fission materials
Fallon, Kealan J.,Budden, Peter,Salvadori, Enrico,Ganose, Alex M.,Savory, Christopher N.,Eyre, Lissa,Dowland, Simon,Ai, Qianxiang,Goodlett, Stephen,Risko, Chad,Scanlon, David O.,Kay, Christopher W. M.,Rao, Akshay,Friend, Richard H.,Musser, Andrew J.,Bronstein, Hugo
, p. 13867 - 13876 (2019)
Singlet fission, the process of forming two triplet excitons from one singlet exciton, is a characteristic reserved for only a handful of organic molecules due to the atypical energetic requirement for low energy excited triplet states. The predominant strategy for achieving such a trait is by increasing ground state diradical character; however, this greatly reduces ambient stability. Herein, we exploit Baird's rule of excited state aromaticity to manipulate the singlet-triplet energy gap and create novel singlet fission candidates. We achieve this through the inclusion of a [4n] 5-membered heterocycle, whose electronic resonance promotes aromaticity in the triplet state, stabilizing its energy relative to the singlet excited state. Using this theory, we design a family of derivatives of indolonaphthyridine thiophene (INDT) with highly tunable excited state energies. Not only do we access novel singlet fission materials, they also exhibit excellent ambient stability, imparted due to the delocalized nature of the triplet excited state. Spin-coated films retained up to 85% activity after several weeks of exposure to oxygen and light, while analogous films of TIPS-pentacene showed full degradation after 4 days, showcasing the excellent stability of this class of singlet fission scaffold. Extension of our theoretical analysis to almost ten thousand candidates reveals an unprecedented degree of tunability and several thousand potential fission-capable candidates, while clearly demonstrating the relationship between triplet aromaticity and singlet-triplet energy gap, confirming this novel strategy for manipulating the exchange energy in organic materials.
Synthesis and properties of indigo based donor-acceptor conjugated polymers
Guo, Chang,Sun, Bin,Quinn, Jesse,Yan, Zhuangqing,Li, Yuning
, p. 4289 - 4296 (2014)
Indigo is for the first time used as a building block to construct polymer semiconductors for organic thin film transistors (OTFTs). Two donor-acceptor polymers using indigo as the acceptor and bithiophene as the donor are synthesized via Stille coupling polymerization. Two types of acyl groups, 2-hexldecanoyl (for polymer P1) and 2-octyldodecanoyl (for polymer P2), are utilized as solubilizing side chains. These polymers possess very deep highest-occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels, due to the strong electron accepting capability of the indigo moiety. In OTFT devices, characteristic n-type semiconductor performance with electron mobility of up to ～10-3 cm2 V-1 s-1 is observed.
Air-stable organic semiconductors based on 6,6′-dithienylindigo and polymers thereof
G?owacki,Apaydin,Bozkurt,Monkowius,Demirak,Tordin,Himmelsbach,Schwarzinger,Burian,Lechner,Demitri,Voss,Sariciftci
, p. 8089 - 8097 (2014)
Herein we report on the synthesis and properties of 6,6′-dithienylindigo (DTI), as well as its solubilized N,N′-di(tert-butoxy carbonyl) derivative (tBOC-DTI). tBOC-DTI can be electropolymerized and thermally interconverted into films of poly(DTI). Thin films of DTI afford quasi-reversible 2-electron reduction and oxidation electrochemistry, and demonstrate ambipolar charge transport in organic field-effect transistors with a hole mobility of up to 0.11 cm2 V-1 s-1 and an electron mobility of up to 0.08 cm2 V-1 s-1. Operation of the p-channel shows excellent air stability, with minimal degradation over a 60 day stressing study. Poly(DTI) can be reversibly oxidized and reduced over hundreds of cycles while remaining immobilized on the working electrode surface, and additionally shows a pronounced photoconductivity response in a diode device geometry. This work shows the potential of extended indigo derivatives for organic electronic applications, demonstrating impressive stability under ambient conditions. This journal is
An indigo-based polymer bearing thermocleavable side chains for n-type organic thin film transistors
Guo, Chang,Quinn, Jesse,Sun, Bin,Li, Yuning
, p. 5226 - 5232 (2015)
A new n-type semiconducting polymer based on indigo having thermocleavable tert-butoxycarbonyl (t-Boc) groups was synthesized and used as an active layer in organic thin film transistors (OTFTs). Twisting of the polymer main chain due to the presence of the bulky t-Boc groups renders this indigo-based polymer highly soluble. A post-deposition thermal treatment at a temperature above 170 °C could remove the t-Boc groups to retrieve the highly coplanar geometry of the unsubstituted indigo units. The thermally annealed polymer semiconductor films at 200 °C showed an electron mobility of up to ～6 × 10-3 cm2 V-1 s-1 in OTFTs, which is a 5-fold increase compared to that of the indigo-based polymers reported previously due to the retrieved high backbone coplanarity. This journal is
A tunable synthesis of indigoids: Targeting indirubin through temperature
Cheek, Joshua T.,Horner, John S.,Kaller, Kaylie S.,Kinsey, Ally L.,Shriver, James A.,Sterrenberg, Summer R.,Van Vors, Madison K.,Wang, Katelyn R.
, p. 5407 - 5414 (2022/03/01)
The spontaneous conversion of 3-indoxyl to indigo is a well-established process used to produce indigo dyes. It was recently shown that some indoles, when reacted with molybdenum hexacarbonyl and cumyl peroxide, proceed through an indoxyl intermediate to produce significant amounts of indirubin through a competing mechanism. Modulation of this system to lower temperatures allows for careful tuning, leading to selective production of indirubins in a general process. A systematic assay of indoles show that electron deficient indoles work well when substituted at the 5 and 7 positions. In contrast, 6-substituted electron rich indoles give the best results whereas halogeno indoles work well in all cases. This process shows broad functional group tolerance for generally reactive carbonyl-containing compounds such as aldehydes and carboxylic acids. This journal is
High-Performance Ambipolar Polymers Based on Electron-Withdrawing Group Substituted Bay-Annulated Indigo
Yang, Jie,Jiang, Yaqian,Tu, Zeyi,Zhao, Zhiyuan,Chen, Jinyang,Yi, Zhengran,Li, Yifan,Wang, Shuai,Yi, Yuanping,Guo, Yunlong,Liu, Yunqi
, (2019/01/05)
For donor–acceptor conjugated polymers, it is an effective strategy to improve their electron mobilities by introducing electron-withdrawing groups (EWGs, such as F, Cl, or CF3) into the polymer backbone. However, the introduction of different EWGs always requires a different synthetic approach, leading to additional arduous work. Here, an effective two-step method is developed to obtain EWG substituted bay-annulated indigo (BAI) units. This method is effective to introduce various EWGs (F, Cl, or CF3) into BAI at different substituted positions. Based on this method, EWG substituted BAI acceptors, including 2FBAI, 2ClBAI, and 2CF3BAI, are reported for the first time. Furthermore, four polymers of PBAI-V, P2FBAI-V, P2ClBAI-V, and P4OBAI-V are developed. All the polymers show ambipolar transport properties. Particularly, P2ClBAI-V exhibits remarkable hole and electron mobilities of 4.04 and 1.46 cm2 V?1 s?1, respectively. These mobilities are among the highest values for BAI-based polymers.
