288574-72-1Relevant academic research and scientific papers
Non-fullerene polymer solar cells with: V OC > 1 v based on fluorinated quinoxaline unit conjugated polymers
He, Baitian,Yin, Qingwu,Yang, Xiye,Liu, Liqian,Jiang, Xiao-Fang,Zhang, Jie,Huang, Fei,Cao, Yong
supporting information, p. 8774 - 8781 (2017/09/12)
To achieve efficient non-fullerene polymer solar cells (NF-PSCs), it is important to design and synthesize donor materials. To investigate the substituent effects of electron-withdrawing fluorine atoms and different alkyl chains (-C8C12 or -C10C14) on the thiophene π bridge, four novel conjugated polymers composed of dicyanodistyrylbenzene (DCB)-based and quinoxaline-based units were synthesized and applied in NF-PSC photovoltaic devices. It was found that the different alkyl side groups had a minimal influence on the molecular energy level but a moderate effect on the absorption coefficient, whereas the highest occupied molecular orbital (HOMO) of the resulting copolymers could be effectively lowered by introducing highly electronegative fluorine atoms into the quinoxaline moiety. As a result, the NF-PSCs based on the fluorinated quinoxaline-based copolymer exhibited high open-circuit voltages (VOC) of up to 1.043 V, which is the highest value to date for devices based on quinoxaline moiety copolymers. Moreover, fluorination also improved the copolymer carrier mobility and absorption coefficient, leading to enhanced JSC and FF, thus giving rise to higher overall efficiencies. NF-PSCs based on PDCB-DFQ812:ITIC exhibited the best performance, with a power conversion efficiency (PCE) of 8.37%. Our comparative research indicates that fluorinated quinoxaline-based conjugated polymers are promising donor materials for NF-PSCs.
Mix and match backbones for the formation of H-bonded duplexes
Iadevaia, Giulia,Stross, Alexander E.,Neumann, Anja,Hunter, Christopher A.
, p. 1760 - 1767 (2016/03/05)
The formation of well-defined supramolecular assemblies involves competition between intermolecular and intramolecular interactions, which is quantified by effective molarity. Formation of a duplex between two oligomers equipped with recognition sites displayed along a non-interacting backbone requires that once one intermolecular interaction has been formed, all subsequent interactions take place in an intramolecular sense. The efficiency of this process is governed by the geometric complementarity and conformational flexibility of the backbone linking the recognition sites. Here we report a series of phosphine oxide H-bond acceptor AA 2-mers and phenol H-bond donor DD 2-mers, where the two recognition sites are connected by isomeric backbone modules that vary in geometry and flexibility. All AA and DD combinations form stable AA·DD duplexes, where two cooperative H-bonds lead to an increase in stability of an order of magnitude compared with the corresponding A·D complexes that can only form one H-bond. For all six possible backbone combinations, the effective molarity for duplex formation is approximately constant (7-20 mM). Thus strict complementarity and high degrees of preorganisation are not required for efficient supramolecular assembly. Provided there is some flexibility, quite different backbone modules can be used interchangeably to construct stable H-bonded duplexes.
Ruthenium-catalyzed knoevenagel condensation: A new route toward cyano-substituted poly(p-phenylenevinylene)s
Liao, Jian,Wang, Qing
, p. 7061 - 7063 (2007/10/03)
The ruthenium-catalyzed Knoevenagel reaction was developed for the preparation of cyano-substituted conjugated polymers. The polymerization was quenched by pouring the reaction mixture into methanol. The structures of polymers were confirmed by spectroscopic studies and elemental analysis. The results show that Knoevenagel polycondensation mediated by transition metal complexes enjoys the advantages of neutral and mild reaction conditions.
