Decarbonative routes to generate -acyliminium ion intermediates for the synthesis of 3-substituted isoindolinones an intermolecular amidoalkylation reaction.

An alternative and unique approach for synthesizing 3-substituted isoindolinones Lewis acid-catalyzed C-C bond-breaking reactions has been reported. For this purpose, we successfully generated -acyliminium ion intermediates from two different substrates [through (a) an FeCl catalyzed C-C bond-breaking reaction in isoindolinones bearing electron-rich and sterically bulky aryl substituents at the 3-position and (b) a ZnCl catalyzed C-C bond-breaking reaction in isoindolinones bearing 1,3-diketo substituents at the 3-position of the isoindolinone starting precursors], which were trapped by appropriate nucleophiles to produce more stable γ-substituted isoindolinones in good to excellent yields. The leaving ability of 1,3-diketones is higher than that of electron-rich and sterically bulky arenes in our developed method, which results in higher yields of γ-substituted isoindolinones from the starting precursor bearing the 1,3-diketo substituents at its 3-position.

A thienoisoindigo-naphthalene polymer with ultrahigh mobility of 14.4 cm(2)/V·s that substantially exceeds benchmark values for amorphous silicon semiconductors.

By considering the qualitative benefits associated with solution rheology and mechanical properties of polymer semiconductors, it is expected that polymer-based electronic devices will soon enter our daily lives as indispensable elements in a myriad of flexible and ultra low-cost flat panel displays. Despite more than a decade of research focused on designing and synthesizing state-of-the-art polymer semiconductors for improving charge transport characteristics, the current mobility values are still not sufficient for many practical applications. The confident mobility in excess of ∼10 cm(2)/V·s is the most important requirement for enabling the realization of the aforementioned near-future products.

Synthesis of PCDTBT-based fluorinated polymers for high open-circuit voltage in organic photovoltaics: towards an understanding of relationships between polymer energy levels engineering and ideal morphology control.

The introduction of fluorine (F) atoms onto conjugated polymer backbone has verified to be an effective way to enhance the overall performance of polymer-based bulk-heterojunction (BHJ) solar cells, but the underlying working principles are not yet fully uncovered. As our attempt to further understand the impact of F, herein we have reported two novel fluorinated analogues of PCDTBT, namely, PCDTFBT (1F) and PCDT2FBT (2F), through inclusion of either one or two F atoms into the benzothiadiazole (BT) unit of the polymer backbone and the characterization of their physical properties, especially their performance in solar cells. Together with a profound effect of fluorination on the optical property, nature of charge transport, and molecular organization, F atoms are effective in lowering both the HOMO and LUMO levels of the polymers without a large change in the energy bandgaps.

Photocurrent spectroscopic studies of diketopyrrolopyrrole-based statistical copolymers.

Diketopyrrolopyrrole (DPP) containing copolymers have gained a lot of interest in organic optoelectronics with great potential in organic photovoltaics. In this work, DPP based statistical copolymers, with slightly different bandgap energies and a varying fraction of donor-acceptor ratio are investigated using monochromatic photocurrent spectroscopy and Fourier-transform photocurrent spectroscopy (FTPS). The statistical copolymer with a lower DPP fraction, when blended with a fullerene derivative, shows the signature of an inter charge transfer complex state in photocurrent spectroscopy.