Near-Infrared Acceptors with Imide-Containing End Groups for Organic Solar Cells.

Near-infrared electron acceptors for organic solar cells (OSCs) mostly contain electron-withdrawing 2-(3-oxo-2,3-dihydro-1-inden-1-ylidene)malononitrile (IC) end groups, which can be modified by but limited to phenyl, thienyl, and naphthyl units with halogenated, methyl, and methyloxy substitution. In this work, we employed an imide-containing unit to construct a new IC end group, based on which a series of new electron acceptors were synthesized. The strong electron-deficient nature of imide units enables the new acceptors to show efficient intramolecular charge transfer and hence red-shifted absorption spectra compared to their IC counterparts.

Fluorescent BF complexes of pyridyl-isoindoline-1-ones: synthesis, characterization and their distinct response to mechanical force.

Three boron-pyridyl-isoindoline-1-one based dyes (B1, B2, and B3) with varied side groups were facilely synthesized. Detailed analyses were carried out concerning the crystal conformation, structure dependent photophysical properties and mechanochromic fluorescence (MCF). The MCF behaviours and solid-state emission were demonstrated to be correlated to the different side groups.