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Fry AM Seibel HA Lokuhewa IN Woodward PM 《Journal of the American Chemical Society》2012,134(5):2621-2625
Na(1.5)Ag(1.5)MoO(3)F(3) and Na(1.5)Ag(1.5)WO(3)F(3) have been synthesized by solid state reactions and structurally characterized using synchrotron X-ray and neutron powder diffraction. Unlike the vast majority of salts containing [MO(3)F(3)](3-) anions (M = Mo, W) the oxyfluoride groups in Na(1.5)Ag(1.5)MoO(3)F(3) and Na(1.5)Ag(1.5)WO(3)F(3) are orientationally ordered, so that the Na(+) ions are coordinated by fluorine and the Ag(+) ions by oxygen. The resulting structure type, which has not previously been reported, is related to the LiNbO(3) structure, but the combination of Na/Ag ordering and orientational ordering of the [MO(3)F(3)](3-) anions produces a supercell that doubles the c-axis and changes the space group symmetry from R3 to R3. The use of hard (Na(+)) and soft (Ag(+)) cations to direct the orientational ordering of polar oxyfluoride building units provides a new approach to the design of polar materials. 相似文献
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Robert J. Koch Indunil N. Lokuhewa Jiawanjun Shi Michael S. Haluska Scott T. Misture 《Journal of Sol-Gel Science and Technology》2012,64(3):612-618
A group of three-layered Aurivillius compounds with composition Bi2A2TiM2O12, where A?=?Ca, Sr, Ba and M?=?Nb and Ta, have been synthesized as nanoscale powders using two variants of the complex polymerization method. A new modified method is presented that yields single phase powders using reaction temperatures as low as 700?°C and accommodates a wide range of chemical substitutions. The resulting crystallites have dimensions below 100?nm and surface area ~10?m2/g. In situ analysis of the decomposition of the polymeric precursor shows that the polymer yields a three-phase mixture consisting of Bi2A2TiM2O12 and the metastable ??- and ??-polymorphs of Bi2O3 upon heating under flowing air. Full kinetics analysis of a 2-step solid state synthesis method was used to demonstrate that the crystallization of ?? Bi2O3 in the sol?Cgel method greatly accelerates the conversion to the Aurivillius phase. The fluorite structure of ?? Bi2O3 is the same as that of the [Bi2O2]2+ layer in the Aurivillius phase, facilitating rapid and low-temperature crystallization of the Aurivillius phase from the ?? Bi2O3 template. 相似文献
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Jiaqi Du Ke Hu Lei Meng Indunil Angunawela Jinyuan Zhang Shucheng Qin Alex Liebman‐Pelaez Chenhui Zhu Zhanjun Zhang Harald Ade Yongfang Li 《Angewandte Chemie (International ed. in English)》2020,59(35):15181-15185
Demonstrated in this work is a simple random ternary copolymerization strategy to synthesize a series of polymer acceptors, PTPBT‐ETx, by polymerizing a small‐molecule acceptor unit modified from Y6 with a thiophene connecting unit and a controlled amount of an 3‐ethylesterthiophene (ET) unit. Compared to PTPBT of only Y6‐like units and thiophene units, PTPBT‐ETx (where x represents the molar ratio of the ET unit) with an incorporated ET unit in the ternary copolymers show up‐shifted LUMO energy levels, increased electron mobilities, and improved blend morphologies in the blend film with the polymer donor PBDB‐T. And the all‐polymer solar cell (all‐PSC) based on PBDB‐T:PTPBT‐ET0.3 achieved a high power conversion efficiency over 12.5 %. In addition, the PTPBT‐ET0.3‐based all‐PSC also exhibits long‐term photostability over 300 hours. 相似文献
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Jiaqi Du Ke Hu Prof. Lei Meng Dr. Indunil Angunawela Dr. Jinyuan Zhang Shucheng Qin Dr. Alex Liebman-Pelaez Dr. Chenhui Zhu Prof. Zhanjun Zhang Prof. Harald Ade Prof. Yongfang Li 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(35):15293-15297
Demonstrated in this work is a simple random ternary copolymerization strategy to synthesize a series of polymer acceptors, PTPBT-ETx, by polymerizing a small-molecule acceptor unit modified from Y6 with a thiophene connecting unit and a controlled amount of an 3-ethylesterthiophene (ET) unit. Compared to PTPBT of only Y6-like units and thiophene units, PTPBT-ETx (where x represents the molar ratio of the ET unit) with an incorporated ET unit in the ternary copolymers show up-shifted LUMO energy levels, increased electron mobilities, and improved blend morphologies in the blend film with the polymer donor PBDB-T. And the all-polymer solar cell (all-PSC) based on PBDB-T:PTPBT-ET0.3 achieved a high power conversion efficiency over 12.5 %. In addition, the PTPBT-ET0.3-based all-PSC also exhibits long-term photostability over 300 hours. 相似文献
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