17.6%-Efficient Quasiplanar Heterojunction Organic Solar Cells from a Chlorinated 3D Network Acceptor.

Bulk heterojunction (BHJ) organic solar cells (OSCs) have achieved great success because they overcome the shortcomings of short exciton diffusion distances. With the progress in material innovation and device technology, the efficiency of BHJ devices is continually being improved. For some special photovoltaic material systems, it is difficult to manipulate the miscibility and morphology of blend films, and this results in moderate, even poor device performance. Quasiplanar heterojunction (Q-PHJ) OSCs have been proposed to exploit the excellent photovoltaic properties of these materials. An OSC with BTIC-BO-4Cl has a 3D interpenetrating network structure with multiple channels that can facilitate the exciton diffusion and charge transport, and BTIC-BO-4Cl is therefore a good candidate for Q-PHJ OSCs. In this work, a D18:BTIC-BO-4Cl-based Q-PHJ device is fabricated. The exciton diffusion lengths of D18 and BTIC-BO-4Cl are in accord with the requirements of the Q-PHJ device and the efficiency of Q-PHJ device is as high as 17.60%. This study indicates that the Q-PHJ architecture can replace the BHJ architecture to produce excellent OSCs for certain unique donors and acceptors, providing an alternative approach to photovoltaic material design and device fabrication.

Nickel-Catalyzed 3,3-Dialkynylation of 2-Aryl Acrylamides: Direct Access to gem-Diethynylethenes via Double Vinylic C-H Bond Activation.

Direct access to gem-diethynylethenes is achieved by a Ni-catalyzed 3,3-dialkynylation of 2-aryl acrylamides with 1-bromotriisopropylsilylacetylene. The preliminary mechanism study reveals that the reaction goes through a sequential double vinylic C-H bond activation with the assistance of an 8-aminoquinolinyl directing group.

Rhodium-Catalyzed C-H/C-H Cross Coupling of Benzylthioethers or Benzylamines with Thiophenes Enabled by Flexible Directing Groups.

Reported herein is an efficient synthetic protocol to ortho-functionalized 2-aryl thiophenes via Rh(III)-catalyzed C-H/C-H cross coupling of benzylthioethers or benzylamines with thiophenes. Both ortho- and meta-substituted benzylthioethers give monoheteroarylated products, while ortho-unhindered substrates mainly provide diheteroarylated benzylthioethers. The C-H/C-H cross coupling of benzylamines with thiophenes exclusively generates diheteroarylated benzaldehydes. Mechanistic investigation discloses a three-step tandem process involving the ortho-C-H diheteroarylation of benzylamine, the oxidation of benzylamine to imine, and the hydrolysis of imine to aldehyde.

Co(iii)-catalyzed Z-selective oxidative C-H/C-H cross-coupling of alkenes with triisopropylsilylacetylene.

A Co(iii)-catalyzed direct oxidative C-H/C-H cross-coupling reaction of acrylamides with triisopropylsilylacetylene is presented. It is applicable to unsubstituted, internal and terminal acrylamides with a broad functionality tolerance. The feasibility of this protocol is successfully demonstrated by the late-stage alkynylation of a derivative of steroid drug Epristeride.