Synthesis of poly(thiophene-alt-pyrrole) from a difunctionalized thienylpyrrole by Kumada polycondensation

He, Lu Ying; Urrego-Riveros, Sara; Gates, Paul J.; Näther, Christian; Brinkmann, Maren; Abetz, Volker; Staubitz, Anne

doi:10.1016/j.tet.2015.05.091

Cited by 7 publications

(6 citation statements)

References 58 publications

(41 reference statements)

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“…[1][2][3][4][5] In the context of attempts of lowering the HOMO-LUMO gaps in materials, bathochromic shifts often are achieved by creating push-pull systems (acceptor-donor-systems) by introducing electron donating and accepting groups on opposite ends of the molecule. [6][7][8] In semiconducting polymers, often two different heterocycles, one electron rich and one electron deficient are coupled. [9][10][11][12] When other main group elements are introduced, the range of possibilities to lower this gap becomes larger: Strategies involve formally antiaromatic compounds such as boroles, 13 or phosphole oxides.…”

Section: Introductionmentioning

confidence: 99%

“…In the context of attempts to lower the highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) gaps in materials, bathochromic shifts often are achieved by creating push–pull systems (acceptor–donor systems) by introducing electron-donating and -accepting groups on opposite ends of the molecule. − In semiconducting polymers, often two different heterocycles, one electron-rich and one electron-deficient, are coupled. − When other main-group elements are introduced, the range of possibilities to lower this gap becomes larger: Strategies involve formally antiaromatic compounds such as boroles or phosphole oxides (for the latter of which the antiaromaticity is due to σ*−π* conjugation). , B–N substitution of (poly)aromatic rings , results in compounds that are formally aromatic but whose charge delocalization around the ring is severely impeded by the very polar B–N substitution, which may aide long-range delocalization of electrons.…”

Section: Introductionmentioning

confidence: 99%

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Tuning the Optoelectronic Properties of Stannoles by the Judicious Choice of the Organic Substituents

et al. 2018

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1 Stannoles are organometallic rings in which the heteroatom is involved in a form of conjugation that involves excited states (σ*-π*-conjugation). Only little is known about how the substituents on the tin atom or substituents on the stannole ring determine the optoelectronic properties of these heterocycles. In this work, this has been studied experimentally and theoretically. Calculations of optimized equilibrium geometries, energy gaps between the HOMOs and LUMOs, and of the absorption spectra of a wide range of compounds were performed. The computational data showed that the substituents on the tin atom influence the optoelectronic properties to a lower extent than the substituents in the 2-and 5-positions of the ring. These substituents in the plane of the stannole ring can also have a strong influence on the overall planarity of the structure, in which mesomeric effects can play a substantial role only if the structure is planar. Thus, only structures with a planar backbone are of interest in the context of tuning optoelectronic properties. These were selected for the experimental studies. Based on this information, a series of six novel stannoles was synthesized by formation of a zirconium intermediate and subsequent transmetalation to obtain the tin compound. The calculated electronic HOMO-LUMO gaps varied between 2.94 eV and 2.68 eV.The measured absorption maxima were located between 415 nm and 448 nm as compared to theoretically calculated values ranging from 447 nm (2.77 eV) to 482 nm (2.57 eV). In addition to these optical measurements, cyclic voltammetry data could be obtained, which show two reversible oxidation processes for three of six stannoles. With this study, it could be demonstrated how the judicious choice of substituents can lead to large and predictable bathochromic shifts in the absorption spectra. ASSOCIATED CONTENT Supporting InformationThe Supporting Information is available free of charge on the ACS Publications website. It includes experimental and analytical details, NMR spectra, cyclic voltammetry and absorption spectra (PDF), crystal structure information (CIF) and all computational data (TXT).

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Tuning the Optoelectronic Properties of Stannoles by the Judicious Choice of the Organic Substituents

et al. 2018

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“…104,105 Recently, He et al showed that Nalkylated pyrroles can be converted to Grignard reagents (when 2-position is attached with a thiophene) by iodination using Niodosuccinimide. 106 Since pyrroles are extremely sensitive to air, all of these reactions require careful synthesis, purification, characterization, and storage. To mitigate this issue, direct arylation can be employed, as showed by Sadighi and coworkers.…”

Section: T H I S C O N T E N T I S O N L Y L I C E N S E D F O R C O ...mentioning

confidence: 99%

“…Another method to install pyrrole as single units is by using mono- or distannylated derivatives in Stille coupling reactions and polymerizations. N -Alkyl pyrroles can be easily converted to the stannyl derivatives by lithiation at the α-positions with BuLi at reflux conditions with N , N , N ′, N ′-tetramethylethylenediamine (TMEDA) as a ligand and hexane as the solvent. ,,− Boronic esters and acids could also be made from pyrrole to undergo Suzuki and Suzuki–Miyura cross-coupling reactions. − Similarly, organozinc complexes could be prepared from pyrroles with lithiation and subsequent transmetalation with ZnCl 2 to perform Kumada and Negishi coupling reactions. , Recently, He et al showed that N -alkylated pyrroles can be converted to Grignard reagents (when 2-position is attached with a thiophene) by iodination using N -iodosuccinimide . Since pyrroles are extremely sensitive to air, all of these reactions require careful synthesis, purification, characterization, and storage.…”

Section: Pyrrole As a Co-monomer/unitmentioning

confidence: 99%

Pyrrole-Containing Semiconducting Materials: Synthesis and Applications in Organic Photovoltaics and Organic Field-Effect Transistors

Bulumulla

Gunawardhana

Gamage

et al. 2020

ACS Appl. Mater. Interfaces

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Organic semiconducting materials derived from πelectron-rich pyrroles have garnered attention in recent years for the development of organic semiconductors. Although pyrrole is the most electron-rich five-membered heteroaromatic ring, it has found few applications in organic photovoltaics and organic field-effect transistors due to synthetic challenges and instability. However, computational modeling assisted screening processes have indicated that relatively stable materials containing pyrrolic units can be synthesized without compromising their inherent electron-donating properties. In this work, we provide a complete, up-to-date review of pyrrole-containing semiconducting materials used for organic photovoltaics and organic field-effect transistors and highlight recent advances in the synthesis of these materials.

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“…Most high-performing donor–acceptor polymers are synthesized in a step-growth manner from two difunctionalized monomers (e.g., a dihalide and a distannane) using tetrakis(triphenyl)phosphine palladium (Pd(PPh 3 ) 4 ). , Similar to the infancy of palladium-catalyzed small-molecule cross-coupling, , Pd(PPh 3 ) 4 is the workhorse precatalyst for conjugated polymers and is often used despite forming undesired (e.g., homocoupled) byproducts. In Pd-catalyzed small-molecule cross-coupling, however, significant developments in catalyst design have now enabled electron-deficient and -rich substrates with unprotected functional groups to be synthesized with few side products. − While hundreds of ancillary ligands have been screened and optimized for these small-molecule cross-coupling reactions, comparatively few have been explored for synthesizing conjugated polymers, leaving a vast range of potential Pd precatalysts for CTP (Chart ) ,,,− These ligands have been specifically optimized for Pd and, as such, will likely be more successful on Pd than on Ni for CTP . Herein, we highlight select examples of catalysts used in small-molecule cross-couplings as inspiration for expanding CTP.…”

Section: Why Palladium?mentioning

confidence: 99%

The History of Palladium-Catalyzed Cross-Couplings Should Inspire the Future of Catalyst-Transfer Polymerization

2018

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Conjugated polymers are the workhorse materials in organic electronics, a field that is rapidly growing to encompass energy storage devices such as supercapacitors and batteries. The highest-performing materials today have incredibly diverse structures and are accessed via step-growth polymerizations. This method results in limited control over the polymer’s molecular weight, sequence, and dispersity, all of which can significantly impact device performance. The discovery of catalyst-transfer polymerization (CTP) in 2004 was predicted to change this landscape. Instead, nearly 14 years later, the CTP scope remains mostly limited to polymerizing small, electron-rich monomers. There is a pronounced gap between the rich array of structures utilized in organic electronics and what can be polymerized in a living, chain-growth fashion via CTP. Here, we suggest that palladium precatalysts could bridge this gap based on their huge versatility in the small-molecule cross-coupling literature. We highlight specific ancillary ligands from the small-molecule literature that we anticipate are candidates for enabling diverse conjugated polymer syntheses based on nearly a decade of research into the CTP mechanism. In addition, we describe several recent promising examples of CTP mediated by Pd precatalysts that serve as inspiration for the future. We present this Perspective as a call-to-action to advance organic electronics with CTP.

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Synthesis of poly(thiophene-alt-pyrrole) from a difunctionalized thienylpyrrole by Kumada polycondensation

Cited by 7 publications

References 58 publications

Tuning the Optoelectronic Properties of Stannoles by the Judicious Choice of the Organic Substituents

Tuning the Optoelectronic Properties of Stannoles by the Judicious Choice of the Organic Substituents

Pyrrole-Containing Semiconducting Materials: Synthesis and Applications in Organic Photovoltaics and Organic Field-Effect Transistors

The History of Palladium-Catalyzed Cross-Couplings Should Inspire the Future of Catalyst-Transfer Polymerization

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