Thiophene-Fused Nickel Dithiolenes: A Synthetic Scaffold for Highly Delocalized π-Electron Systems.

A series of thiophene-fused nickel dithiolene complexes have been prepared via synthetic methods which allow the addition of peripheral aryl groups to the fused thiophene of the dithiolene ligand, thus providing access to a range of structural and electronic modifications to the dithiolene core. X-ray structural studies of the anionic complexes show that the peripheral aryl rings lie in near-perfect coplanarity to the dithiolene core and can form π-stacked columns with N-methylpyridinium cations. Density functional theory calculations show significant delocalization of the frontier orbital electron density into the peripheral aryl rings.

Fluorescent thiophene-based materials and their outlook for emissive applications.

Although thiophene-based materials are among the most widely studied conjugated materials for a number of technological applications, most discussions of emissive conjugated materials have focused on other systems, primarily due to the lower emission quantum yields of thiophene-based systems. Over the last decade, however, this has begun to change with the development of new highly emissive thiophene-based materials. In this review, we provide an overview of fluorescent thiophene-based materials and their applications, highlighting in particular the various methods employed to achieve highly emissive materials, as well as a variety of reported applications including fluorescent biomarkers and organic light emitting diodes.

Molecular tuning in highly fluorescent dithieno[3,2-b:2',3'-d]pyrrole-based oligomers: effects of N-functionalization and terminal aryl unit.

A series of eight conjugated oligomers consisting of central dithieno[3,2-b:2',3'-d]pyrroles (DTPs) end-capped with either thienyl or phenyl groups have been prepared from N-alkyl-, N-aryl-, and N-acyl-dithieno[3,2-b:2',3'-d]pyrroles via Stille and Suzuki cross-coupling. The DTP-based quaterthiophene, N-phenyl-2,6-bis(2-thienyl)dithieno-[3,2-b:2',3'-d]pyrrole was characterized via X-ray crystallography and was found to crystallize in the orthorhombic space group Pna2(1) with a = 10.8666(3) Å, b = 22.

N-acyldithieno[3,2-b:2',3'-d]pyrroles: second generation dithieno[3,2-b:2',3'-d]pyrrole building blocks with stabilized energy levels.

A new class of dithieno[3,2-b:2',3'-d]pyrroles (DTPs) incorporating N-acyl groups have been prepared from 3-bromothiophene via copper-catalyzed amidation. The utilization of various electron-withdrawing acyl groups has allowed stabilization of the HOMO and LUMO energy levels of these popular building blocks for conjugated materials. The synthesis and characterization of this new class of compounds is described, including electrochemical and photophysical data for all compounds and X-ray structural data for the octanoyl, benzoyl, and cyclohexanoyl functionalized compounds.