ABSTRACT
The syntheses of four triptycene-bis(aroyleneimidazole)s-the missing links with respect to the previously reported triptycene-mono(aroyleneimidazole)s and triptycene-tris(aroyleneimidazole)s-are presented. Their optoelectronic properties and use as non-fullerene acceptors in organic photovoltaics with poly({4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl}[3-fluoro-2-(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl) (PTB7) as a donor are described; these systems reach a maximum power conversion efficiency of 2 %. Furthermore, the effect of molecular symmetry on the photovoltaic device performance is discussed.
ABSTRACT
Two soluble isomeric acceptor molecules based on a triptycene core, which is connected to three aroylenimidazole units are described. Due to the inherent threefold axis, the molecules are soluble and thus could be fully photophysically characterized in solution and film. Additionally, the preliminary results of these acceptors in organic photovoltaic devices with two different donor materials are reported.
ABSTRACT
The pseudo-octahedral molybdenum benzylidyne complex [TolC≡Mo(ONO)(OR)]·KOR (R = CCH3(CF3)2) 1, featuring a stabilizing ONO pincer ligand, initiates the controlled living polymerization of strained dibenzocyclooctynes at T > 60 °C to give high molecular weight polymers with exceptionally low polydispersities (PDI â¼ 1.02). Kinetic analyses reveal that the growing polymer chain attached to the propagating catalyst efficiently limits the rate of propagation with respect to the rate of initiation (kp/ki â¼ 10(-3)). The reversible coordination of KOCCH3(CF3)2 to the propagating catalyst prevents undesired chain-termination and -transfer processes. The ring-opening alkyne metathesis polymerization with 1 has all the characteristics of a living polymerization and enables, for the first time, the controlled synthesis of amphiphilic block copolymers via ROAMP.
