High-performance donor-acceptor electron acceptors containing 2-(3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile(INCN)-type terminals are labile toward photooxidation and basic conditions,and new molecular designs ...High-performance donor-acceptor electron acceptors containing 2-(3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile(INCN)-type terminals are labile toward photooxidation and basic conditions,and new molecular designs toward electron acceptors that can achieve both high power conversion efficiencies and high stability are urgently needed.By replacing the central benzene ring in the classical ladder-type n-type semiconductor,2,2′-(indeno[1,2-b]fluorene-6,12-diylidene)dimalononitrile,with the electron-rich 4,4,9,9-tetrahexyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b′]dithiophene,we report herein the design of 2,2′-(7,7,15,15-tetrahexyl-7,15-dihydro-sindaceno[1,2-b:5,6-b′]diindeno[1,2-d]thiophene-2,10(2H)-diylidene)dimalononitrile(ITYM),a new type of all-fused-ring electron acceptor(AFRA).A threestep reaction including a key Pd-catalyzed double C-H activation/intramolecular cyclization is established for the efficient synthesis of such type of electron acceptors.ITYM is confirmed by singlecrystal X-ray analysis,which shows a planar nonacyclic structure with strongπ-πstacking.Compared with the classical carbon-bridged INCN-type acceptors,ITYM exhibits extraordinary stability with very promising performance.The AFRA concept opens a new avenue toward high-efficiency and-stability organic photovoltaics(OPVs).展开更多
基金The authors thank the National Key R&D Program of China(nos.2019YFA0705900 and 2017YFA0204701)the National Natural Science Foundation of China(nos.21661132006 and 91833304)for their financial support。
文摘High-performance donor-acceptor electron acceptors containing 2-(3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile(INCN)-type terminals are labile toward photooxidation and basic conditions,and new molecular designs toward electron acceptors that can achieve both high power conversion efficiencies and high stability are urgently needed.By replacing the central benzene ring in the classical ladder-type n-type semiconductor,2,2′-(indeno[1,2-b]fluorene-6,12-diylidene)dimalononitrile,with the electron-rich 4,4,9,9-tetrahexyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b′]dithiophene,we report herein the design of 2,2′-(7,7,15,15-tetrahexyl-7,15-dihydro-sindaceno[1,2-b:5,6-b′]diindeno[1,2-d]thiophene-2,10(2H)-diylidene)dimalononitrile(ITYM),a new type of all-fused-ring electron acceptor(AFRA).A threestep reaction including a key Pd-catalyzed double C-H activation/intramolecular cyclization is established for the efficient synthesis of such type of electron acceptors.ITYM is confirmed by singlecrystal X-ray analysis,which shows a planar nonacyclic structure with strongπ-πstacking.Compared with the classical carbon-bridged INCN-type acceptors,ITYM exhibits extraordinary stability with very promising performance.The AFRA concept opens a new avenue toward high-efficiency and-stability organic photovoltaics(OPVs).
基金financially supported by the National Key Research and Development Program of China(2019YFA0705900)funded by the Ministry of Science and Technology(MOST)the National Natural Science Foundation of China(52073281,22135007 and 21875244)the Natural Science Foundation of Jilin Province(20230101122JC)。
