66522-06-3Relevant articles and documents
Correlating cobalt redox couples to photovoltage in the dye-sensitized solar cell
Chen, Kitty Y.,Schauer, Phil A.,Patrick, Brian O.,Berlinguette, Curtis P.
, p. 11942 - 11952 (2018)
We report a series of structurally analogous cobalt mediators related to [Co-bpy]Z (bpy = 2,2′-bipyrimidine, Z = 2+ or 3+) to demonstrate a linear relationship between the redox potential of the Co(iii/ii)-based redox couple (Emed) and open-circuit voltage (VOC) of the DSSC. The Emed values vary from 0.42 to 1.07 V vs. NHE depending on the number of nitrogen atoms and the presence of tert-butyl substituents on the ligand. A 64-mV gain in photovoltage was calculated for every +100 mV shift in Emed. Differences in the mediator sizes, diffusion coefficients, light absorption profiles, and spin state configurations for the complexes were not significant and therefore not expected to contribute to changes in the VOC. A decrease in the photocurrent, downward shift in quasi-Fermi level (EF,n) and shorter electron lifetime (Tn) with increasingly positive Emed were instead attributed to enhanced electron recombination from the TiO2 film to oxidized mediator species in the electrolyte.
Functional Pyrimidinyl Pyrazolate Pt(II) Complexes: Role of Nitrogen Atom in Tuning the Solid-State Stacking and Photophysics
Ganesan, Paramaguru,Hung, Wen-Yi,Tso, Jen-Yung,Ko, Chang-Lun,Wang, Tsai-Hui,Chen, Po-Ting,Hsu, Hsiu-Fu,Liu, Shih-Hung,Lee, Gene-Hsiang,Chou, Pi-Tai,Jen, Alex K.-Y.,Chi, Yun
, (2019/05/15)
Pt(II) metal complexes are known to exhibit strong solid-state aggregation and are promising for realization of efficient emission in fabrication of organic light emitting diodes (OLED) with nondoped emitter layer. Four pyrimidine–pyrazolate based chelates, together with four isomeric Pt(II) metal complexes, namely: [Pt(pm2z)2], [Pt(tpm2z)2], [Pt(pm4z)2], and [Pt(tpm4z)2], are isolated and systematically investigated for their structure–property relationships for practical OLED applications. Detailed single molecular and aggregated structures are revealed by photophysical and mechanochromic measurements, grazing-incidence X-ray diffraction, and theoretical approaches. These results suggest that these Pt(II) emitters pack like a deck of playing cards under vacuum deposition, and their emission energy is not only affected by the single molecular designs, but notably influenced by their intermolecular packing interaction, i.e., Pt···Pt separations that are arranged in the order: [Pt(tpm4z)2] > [Pt(pm4z)2] > [Pt(tpm2z)2] > [Pt(pm2z)2]. Nondoped OLED with emission ranging from green to red are prepared, to which the best performances are recorded for [Pt(tpm2z)2], giving maximum external quantum efficiency (EQE) of 27.5% at 103 cd m?2, maximum luminance of 2.5 × 105 cd m?2 at 17 V, and with stable CIEx,y of (0.56, 0.44).
Silver catalysed decarboxylative alkylation and acylation of pyrimidines in aqueous media
Mai, Wen-Peng,Sun, Bin,You, Li-Qin,Yang, Liang-Ru,Mao, Pu,Yuan, Jin-Wei,Xiao, Yong-Mei,Qu, Ling-Bo
, p. 2750 - 2755 (2015/04/21)
Decarboxylative alkylation or acylation reactions of simple pyrimidines have been developed in aqueous media. Using aliphatic carboxylic acids or 2-oxocarboxylic acids and pyrimidines as substrates and silver as the catalyst, the 4-substituted alkyl or ac