Regiocontrolled Electrosynthesis of [60]Fullerene Bisadducts: Photovoltaic Performance and Crystal Structures of C₆₀ o-Quinodimethane Bisadducts

Abstract

C o-quinodimethane bisadducts [C(QM)] are promising electron acceptors for bulk heterojuction (BHJ) organic solar cells (OSCs). However, previous production of C(QM) often resulted in excessive regioisomers, which were difficult to purify and might consequently obscure the structure-performance study of the organofullerene acceptors. Herein, the electrosynthesis of C(QM) is reported. The reaction exhibits a strong regiocontrol with generation of fewer regioisomers. Pure regioisomers of cis-2, trans-3, and e C(QM) are obtained, and the structures are solved with single-crystal X-ray diffraction. Interestingly, the cis-2 and trans-3 regioisomers exhibit better photovoltaic performance than the e regioisomer in the OSCs based on poly(3-hexylthiophene) (P3HT), which can be correlated with their structural difference.

Enhanced Electronic Quality of Perovskite via a Novel C60 o-Quinodimethane Bisadducts toward Efficient and Stable Perovskite Solar Cells

“…It can be observed from Figure a that the final PSCs presents the configuration with FTO/TiO 2 /SnO 2 /MAPbI 3 :C 60 (QM) 2 /Spiro-OMeTAD/Ag. The detailed fabrication process is demonstrated in the device fabrication, and the molecular structure for the C 60 (QM) 2 is exhibited in the Figure b, which widely serves as an electron acceptor material in the organic photovoltaic field due to its relatively good electronic properties Figure c presents the corresponding cross-section SEM image for the final PSCs, it is noted that compared with the MAPbI 3 layer thickness, the grain sizes of many perovskite crystallites are larger and most of the GBs are vertical to the TiO 2 /SnO 2 layer, which could effectually minimize the GB energy and improve the carrier transport.…”

Electrifying green synthesis: recent advances in electrochemical annulation reactions

“…Gao and co-workers proposed an electrosynthetic approach for the preparation of C 60 o-quinodimethane bisadducts [C 60 (QM) 2 ] (Scheme 41). 175 The authors emphasized the importance of these products in the study of organic solar cells (OSC); 176 however, the synthetic methodologies previously described resulted in up to 8 regioisomers. 177 Electrolysis showed high regiocontrol, providing cis-2, trans-3 and C 60 (QM) 2 products.…”

Synthesis of (MeO)2Bn2C70: Regiochemistry of 2-fold Additions to C70 with Addends That Are Preferential for Ortho Addition and Capable of Para Addition

“…The 2-fold additions of methoxy and benzyl groups to C 70 were performed by reacting C 70 with MeO − (8 equiv) and BnBr (16 equiv) in an o-DCB solution. Different from the C 60 reaction, in which only one tetraadduct (5) was obtained, 23a the reaction produced three C 70 tetraadducts, 2,10-(MeO) 2 -5,9-Bn 2 C 70 (6), 1,56-Bn 2 -2,57-(MeO) 2 C 70 (7), and 1,41-Bn 2 -2,58-(MeO) 2 C 70 (8). 24 A methanol solution of 1.0 M TBAOH (tetra-n-butylammonium hydroxide) was employed as the MeO − source, which exhibited a reactivity better than that of NaOMe likely because of a better solubility in the organic solvent.…”

“…However, the reactions are often complicated by the formation of many regioisomers, , which are difficult to purify and may lower the performance of the devices due to the disordered packing of the regioisomeric mixture. Study of the regioselectivity of 2-fold additions to fullerenes is therefore important not only in revealing the intrinsic reactivity of these carbon cages but also in the pursuit of better OSC devices. − …”