Synthesis and Electronic Properties of Aldehyde End-Capped Thiophene Oligomers and Other α,ω-Substituted Sexithiophenes

Abstract

A series of α,ω-aldehyde end-capped oligomers of thiophene with three, four, five, six, and eight thiophene units have been synthesized using the palladium-catalyzed Stille's coupling reactions. The UV−vis spectral data indicate that these aldehyde end-capped oligomers have longer conjugation lengths as evidenced by the higher λmax values than the corresponding unsubstituted oligothiophenes. The λmax value increases as the number of thiophene units is increased. The intrinsic conductivity of the solution-cast films of the aldehyde end-capped oligothiophenes is generally higher than that of their corresponding unsubstituted counterparts. Other α,ω-substituted sexithiophenes, such as n-dodecanoyl, tert-butyldimethylsilyl, hydroxymethyl, and [(n-butoxyethoxy)ethoxy]methyl sexithiophenes, have also been synthesized. α,ω-Bis([(n-butoxyethoxy)ethoxy]methyl)sexithiophene has a remarkably high solubility in chloroform (1.8 g/L) and a conductivity (1 × 10-6 S/cm) comparable to the unsubstituted sexithiophene.

β‐Substituted Terthiophene [2]Rotaxanes

“…3 Tb-DEG was synthesized using palladium-catalyzed Stille coupling with 2,5-stannylated thiophene 6 and 5. [16] In this step we obtained a small amount of the thiophene derivatives with higher molecular weight (quaterthiophene etc.). As some side-products, which contains the product originating from 2,3-substituted thiophene derivative, were inseparable through silica gel chromatography, we obtained pure product using a preparative HPLC.…”

“…3-Thiophenemethanol and N-bromosuccinimide (NBS) were purchased from Sigma-Aldrich Co. All of the reagents and solvents were used without further purification. 2,5-Dibromo-3-thiophene methanol (1), [14] 2-[2-(2-bromoethoxy)ethoxy]tetrahydro-2H-pyran (2), [10] 2,5-stannylated thiophene (6) [16] and cyclobis-…”

Phenacyl–Thiophene and Quinone Semiconductors Designed for Solution Processability and Air‐Stability in High Mobility n‐Channel Field‐Effect Transistors

“…The Stille reagent 5,5'-bis(tributylstannyl)-2,2'-bithiophene was synthesized according to a published procedure. [46] Materials 5,5'''-bis(perfluorophenylcarbonyl)-2,2':5',2'':5'',2'''-quaterthiophene (1), 5,5'''-bis(phenylcarbonyl)-2,2':5',2'':5'',2'''-quaterthiophene (2), poly-…”

Tuning the Semiconducting Properties of Sexithiophene byα,ω-Substitution—α,ω-Diperfluorohexylsexithiophene: The First n-Type Sexithiophene for Thin-Film Transistors

“…The reagents 5-bromo-2,2'-dithiophene (4), [24] and 5,5'-bis(tri-n-butylstannyl)-2,2'-dithiophene [25] were prepared according to known procedures. Solvents and chemicals were purchased from Aldrich or Lancaster and purified as required.…”