Naphthodithiophenes: Emerging Building Blocks for Organic Electronics

Abstract

Linear-fused naphthodithiophenes (NDTs) are emerging building blocks in the development of new semiconducting small molecules, oligomers, and polymers. The promising nature of NDT-based materials as organic semiconductors has been demonstrated by superior device characteristics in organic field-effect transistors (OFETs) and organic photovoltaics (OPVs) in the last few years. In particular, it is quite impressive that a power conversion efficiency as high as 8.2% has been achieved for a single-junction OPV cell consisting of NDT-based semiconducting polymers and a fullerene derivative in such a short period of time. Here, we provide an overview of recent synthetic evolutions in NDT chemistry and progress in NDT-based materials, especially conjugated oligomers and polymers and their applications to OFETs and OPVs.

Thiophene-Fused Naphthalene Diimides: New Building Blocks for Electron Deficient π-Functional Materials

“…13 Development of new π-conjugated building blocks that can be integrated into molecular or macromolecular systems is key to the evolution of new organic semiconductors. 46 In this context, building blocks for p-type organic semiconductors have been intensely developed in the last two decades, affording promising device performances; e.g., very high hole mobility in organic field-effect transistors (OFETs), 710 high power conversion efficiency (PCE) in donor polymers/PCBMs-based organic photovoltaics (OPVs), 11,12 and p-type organic thermoelectric (TE) devices. 13 Although the development of n-type building blocks has been lagging behind the p-type counterparts, development of n-type building blocks has recently received considerable attention, 1416 as they can contribute to development of various organic semiconducting materials including not only n-type semiconductors but also ambipolar semiconductors as well as p-type semiconducting polymers with donor-acceptor (D-A) architecture.…”

Metal‐Free Synthesis of Benzothiophenes by Twofold C−H Functionalization: Direct Access to Materials‐Oriented Heteroaromatics

“…We have also demonstrated an iterative functionalization of simple arenes to obtain benzodithiophene (BDT) compounds. Thus, by consecutive C−H functionalization/π‐extension we were able to prepare the cross‐fused napthodithiophene derivative 3 w′ , further illustrating the potential of this methodology for the rapid construction of interesting thienoacene materials …”

“…This constitutes an efficient, one-pot synthesis of benzothiophenes through am etal-free,t hienannulative p-extension reaction. [3,23] Scheme 3. Importantly,t he use of polyaromatic hydrocarbons such as naphthalene,fluoranthrene,pyrene and corannulene directly delivered arange of interesting polyaromatic benzothiophene products (3p' '-3t' ', 3v' ').…”

Metal‐Free Synthesis of Benzothiophenes by Twofold C−H Functionalization: Direct Access to Materials‐Oriented Heteroaromatics

“…[7] We have also demonstrated an iterative functionalization of simple arenes to obtain benzodithiophene (BDT) compounds.Thus,byconsecutive C À Hfunctionalization/p-extension we were able to prepare the cross-fused napthodithiophene derivative 3w' ',further illustrating the potential of this methodology for the rapid construction of interesting thienoacene materials. [3,23] Scheme 3. Scope of the transition metal-free, one-pot synthesis of pextended benzothiophenes.…”