Acid loss and plasticization of phosphoric acid(PA)-doped high-temperature polymer electrolyte membranes(HT-PEMs)are critical limitations to their practical application in fuel cells.To overcome these barriers,poly(te...Acid loss and plasticization of phosphoric acid(PA)-doped high-temperature polymer electrolyte membranes(HT-PEMs)are critical limitations to their practical application in fuel cells.To overcome these barriers,poly(terphenyl piperidinium)s constructed from the m-and p-isomers of terphenyl were synthesized to regulate the microstructure of the membrane.Highly rigid p-terphenyl units prompt the formation of moderate PA aggregates,where the ion-pair interaction between piperidinium and biphosphate is reinforced,leading to a reduction in the plasticizing effect.As a result,there are trade-offs between the proton conductivity,mechanical strength,and PA retention of the membranes with varied m/p-isomer ratios.The designed PA-doped PTP-20m membrane exhibits superior ionic conductivity,good mechanical strength,and excellent PA retention over a wide range of temperature(80–160°C)as well as satisfactory resistance to harsh accelerated aging tests.As a result,the membrane presents a desirable combination of performance(1.462 W cm^(-2) under the H_(2)/O_(2)condition,which is 1.5 times higher than that of PBI-based membrane)and durability(300 h at 160°C and 0.2 A cm^(-2))in the fuel cell.The results of this study provide new insights that will guide molecular design from the perspective of microstructure to improve the performance and robustness of HT-PEMs.展开更多
A new 3D Cd（II） coordination polymer, [Cd2L（phen）（HzO）]n （1, HaL = terphenyl- 2,2＇,4,4＇-tetracarboxylic acid, phen = 1,10-phenanthroline）, has been hydrothermally synthesized and characterized by single-crys...A new 3D Cd（II） coordination polymer, [Cd2L（phen）（HzO）]n （1, HaL = terphenyl- 2,2＇,4,4＇-tetracarboxylic acid, phen = 1,10-phenanthroline）, has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction analysis, elemental analysis, TGA and IR spectroscopy. Complex 1 crystallizes in the monoclinic system, space group P21/c with a = 8.196（2）, b = 18.348（5）, c = 19.036（5） A, β = 97.741（5）°, V= 2836.6（14） A3, Z = 4, Dc = 1.933 Mg.m-3, p = 1.565 mm1, F（000） = 1624, the final R = 0.0356 and wR = 0.0612 for 4990 observed reflections with 1 〉 2a（I）. Complex 1 has a 1D chain containing Cd4 structural units, which are linked by 2- and 2＇-carboxyl groups of L4- to result in a 3D framework. Additionally, the photoluminescent property of 1 was also studied in the solid state at room temperature.展开更多
A new p-terphenyl derivative 1 was isolated from the fruiting bodies of Boletopsis grisea. Its structure was established as 2. 3-diacetoxy-4 ', 4 ', 5, 6-tetrahydroxy-p-terphenyl by spectroscopic and chemical ...A new p-terphenyl derivative 1 was isolated from the fruiting bodies of Boletopsis grisea. Its structure was established as 2. 3-diacetoxy-4 ', 4 ', 5, 6-tetrahydroxy-p-terphenyl by spectroscopic and chemical means.展开更多
Relationships between the structure characteristics of natural p-terphenyl com- pounds isolated from three edible mushrooms （Thelephora ganbajun, Thelephora aeronautical, and Boletopsis grisea） indigenous to China a...Relationships between the structure characteristics of natural p-terphenyl com- pounds isolated from three edible mushrooms （Thelephora ganbajun, Thelephora aeronautical, and Boletopsis grisea） indigenous to China and their mechanism of antioxidant activity were studied. Geometry structures of terphenyl molecule and four corresponding radicals, bond dissociation energy （BDE）, frontier orbitals （HOMO and LUMO） and single electron density were calculated using DFT methods （B3LYP/6-311G＊＊）. The computational results which are consistent with the experimental data well show that terphenyl molecule scavenges DPPH radical by hydrogen abstract mechanism and the high antioxidant activity depends on the substitution position of hydroxyls. Two active 7-, 8-hydroxyls facilitate the hydrogen abstraction due to the intramolecular hydrogen bond and the resonance effect makes 4-hydroxyl radical more stable.展开更多
Solvothermal reaction of aromatic terphenyl-2,5,2＇,5＇-tetracarboxylic acid （Hnqptc） ligand and the transitional metal cation of Mn11 in the presence of 3-（2-pyridyl）pyrazole （pp） affords one new coordination p...Solvothermal reaction of aromatic terphenyl-2,5,2＇,5＇-tetracarboxylic acid （Hnqptc） ligand and the transitional metal cation of Mn11 in the presence of 3-（2-pyridyl）pyrazole （pp） affords one new coordination polymer, [Mn（qptc）0.5（pp）2]n·n（H2O） （1）. The structure has been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR, TGA, and magnetism. The carboxyl groups of qptc4 exhibit a μ1-η1：η0 coordination mode, and the qptc4- acts as a H-shaped ligand linking the Mn11 centers together to form a 2D polymeric [Mn（qptc）0.5]n layer. The crystal of 1 crystallizes in orthorhombic, space group Pbca with a = 9.3119（12）, b = 20.848（3）, c = 26.134（3） A, V= 5073.4（11） A3, Z= 8, C27HIgMnN6O5,Mr=562.42, Dc = 1.473 g/cm3, F（000） = 2304 and μ（MoKa） = 0.571 mm-1. The final R = 0.0468 and wR = 0.1196 for 4429 observed reflections with I 〉 2σ（I） and R = 0.0797 and wR = 0.1383 for all data.展开更多
Novel side-chain liquid-crystalline poly(meth)acrylates were synthesized using 1-(3-hydroxyl-propyl)-3-[(4 '-cyano-p-terphenyloxycarbonyl)alkyl]-1,1,3,3-tetramethyldisiloxane as the key intermediate. The polymers ...Novel side-chain liquid-crystalline poly(meth)acrylates were synthesized using 1-(3-hydroxyl-propyl)-3-[(4 '-cyano-p-terphenyloxycarbonyl)alkyl]-1,1,3,3-tetramethyldisiloxane as the key intermediate. The polymers used a disiloxane moiety as decoupling spacer with cyano-p-terphenyl as mesogenic unit. The products were characterized by NMR, GPC, DSC and polarizing optical microscopy. All the polymers with cyano-p-terphenyl mesogens formed a stable mesophase. However, if the mesogenic unit is replaced by cyano-p-biphenyl, the liquid crystalline character will be lost. The results also showed that the decoupling is incomplete even if a complex and very flexible decoupling spacer is deliberately incorporated to obtain the highest possible decoupling effect.展开更多
A simple and efficient catalytic system for Na2PdC14 catalyzing the Suzuki-Miyaura reaction of dibromoben- zene and arylboronic acid has been developed by using 2N2O-salen as a ligand in H2O/EtOH （V ： V=4 ： 1） at ...A simple and efficient catalytic system for Na2PdC14 catalyzing the Suzuki-Miyaura reaction of dibromoben- zene and arylboronic acid has been developed by using 2N2O-salen as a ligand in H2O/EtOH （V ： V=4 ： 1） at 100 ℃. Using this method, the reactions of substrates containing sterically demanding ortho substituents （e.g. dibromo- benzene and/or arylboronic acids） proceeded efficiently, with the corresponding terphenyl derivatives being pro- duced in moderate to excellent yields. Furthermore, this method offers interesting features for the multi-gram scale synthesis of terphenyl compound.展开更多
基金supported by The National Key Research and Development Program of China(2021YFB4001204)National Natural Science Foundation of China(22379143)。
文摘Acid loss and plasticization of phosphoric acid(PA)-doped high-temperature polymer electrolyte membranes(HT-PEMs)are critical limitations to their practical application in fuel cells.To overcome these barriers,poly(terphenyl piperidinium)s constructed from the m-and p-isomers of terphenyl were synthesized to regulate the microstructure of the membrane.Highly rigid p-terphenyl units prompt the formation of moderate PA aggregates,where the ion-pair interaction between piperidinium and biphosphate is reinforced,leading to a reduction in the plasticizing effect.As a result,there are trade-offs between the proton conductivity,mechanical strength,and PA retention of the membranes with varied m/p-isomer ratios.The designed PA-doped PTP-20m membrane exhibits superior ionic conductivity,good mechanical strength,and excellent PA retention over a wide range of temperature(80–160°C)as well as satisfactory resistance to harsh accelerated aging tests.As a result,the membrane presents a desirable combination of performance(1.462 W cm^(-2) under the H_(2)/O_(2)condition,which is 1.5 times higher than that of PBI-based membrane)and durability(300 h at 160°C and 0.2 A cm^(-2))in the fuel cell.The results of this study provide new insights that will guide molecular design from the perspective of microstructure to improve the performance and robustness of HT-PEMs.
基金supported by the National Natural Science Foundation of China (21103146)the Natural Scientific Foundation of Shaanxi Province (2012JM2015)the Natural Scientific Research Foundation of Shaanxi Provincial Education Office (11JK0567)
文摘A new 3D Cd（II） coordination polymer, [Cd2L（phen）（HzO）]n （1, HaL = terphenyl- 2,2＇,4,4＇-tetracarboxylic acid, phen = 1,10-phenanthroline）, has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction analysis, elemental analysis, TGA and IR spectroscopy. Complex 1 crystallizes in the monoclinic system, space group P21/c with a = 8.196（2）, b = 18.348（5）, c = 19.036（5） A, β = 97.741（5）°, V= 2836.6（14） A3, Z = 4, Dc = 1.933 Mg.m-3, p = 1.565 mm1, F（000） = 1624, the final R = 0.0356 and wR = 0.0612 for 4990 observed reflections with 1 〉 2a（I）. Complex 1 has a 1D chain containing Cd4 structural units, which are linked by 2- and 2＇-carboxyl groups of L4- to result in a 3D framework. Additionally, the photoluminescent property of 1 was also studied in the solid state at room temperature.
文摘A new p-terphenyl derivative 1 was isolated from the fruiting bodies of Boletopsis grisea. Its structure was established as 2. 3-diacetoxy-4 ', 4 ', 5, 6-tetrahydroxy-p-terphenyl by spectroscopic and chemical means.
基金Supported by NNSFC(10901135,11171293)Natural Science Foundation of Yunnan Province(2008CD081,2010CC003)+1 种基金Educational Commission of Yunnan Province(2011Y296)Foundation of Honghe University(2010PY0104,10XJY113)
文摘Relationships between the structure characteristics of natural p-terphenyl com- pounds isolated from three edible mushrooms （Thelephora ganbajun, Thelephora aeronautical, and Boletopsis grisea） indigenous to China and their mechanism of antioxidant activity were studied. Geometry structures of terphenyl molecule and four corresponding radicals, bond dissociation energy （BDE）, frontier orbitals （HOMO and LUMO） and single electron density were calculated using DFT methods （B3LYP/6-311G＊＊）. The computational results which are consistent with the experimental data well show that terphenyl molecule scavenges DPPH radical by hydrogen abstract mechanism and the high antioxidant activity depends on the substitution position of hydroxyls. Two active 7-, 8-hydroxyls facilitate the hydrogen abstraction due to the intramolecular hydrogen bond and the resonance effect makes 4-hydroxyl radical more stable.
基金supported from the Opening Foundation of Shandong Provincial Key Laboratory of Fluorine Chemistry and Chemical Materials,the National Natural Science Foundation of China(20873150)the Natural Science Foundation of Shandong Province(ZR2010BQ023)the Outstanding Middle-aged Scientists Foundation of Shandong Province(2008BS04031)
文摘Solvothermal reaction of aromatic terphenyl-2,5,2＇,5＇-tetracarboxylic acid （Hnqptc） ligand and the transitional metal cation of Mn11 in the presence of 3-（2-pyridyl）pyrazole （pp） affords one new coordination polymer, [Mn（qptc）0.5（pp）2]n·n（H2O） （1）. The structure has been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR, TGA, and magnetism. The carboxyl groups of qptc4 exhibit a μ1-η1：η0 coordination mode, and the qptc4- acts as a H-shaped ligand linking the Mn11 centers together to form a 2D polymeric [Mn（qptc）0.5]n layer. The crystal of 1 crystallizes in orthorhombic, space group Pbca with a = 9.3119（12）, b = 20.848（3）, c = 26.134（3） A, V= 5073.4（11） A3, Z= 8, C27HIgMnN6O5,Mr=562.42, Dc = 1.473 g/cm3, F（000） = 2304 and μ（MoKa） = 0.571 mm-1. The final R = 0.0468 and wR = 0.1196 for 4429 observed reflections with I 〉 2σ（I） and R = 0.0797 and wR = 0.1383 for all data.
基金This work was supported by NNSFC (No. 59873001).
文摘Novel side-chain liquid-crystalline poly(meth)acrylates were synthesized using 1-(3-hydroxyl-propyl)-3-[(4 '-cyano-p-terphenyloxycarbonyl)alkyl]-1,1,3,3-tetramethyldisiloxane as the key intermediate. The polymers used a disiloxane moiety as decoupling spacer with cyano-p-terphenyl as mesogenic unit. The products were characterized by NMR, GPC, DSC and polarizing optical microscopy. All the polymers with cyano-p-terphenyl mesogens formed a stable mesophase. However, if the mesogenic unit is replaced by cyano-p-biphenyl, the liquid crystalline character will be lost. The results also showed that the decoupling is incomplete even if a complex and very flexible decoupling spacer is deliberately incorporated to obtain the highest possible decoupling effect.
文摘A simple and efficient catalytic system for Na2PdC14 catalyzing the Suzuki-Miyaura reaction of dibromoben- zene and arylboronic acid has been developed by using 2N2O-salen as a ligand in H2O/EtOH （V ： V=4 ： 1） at 100 ℃. Using this method, the reactions of substrates containing sterically demanding ortho substituents （e.g. dibromo- benzene and/or arylboronic acids） proceeded efficiently, with the corresponding terphenyl derivatives being pro- duced in moderate to excellent yields. Furthermore, this method offers interesting features for the multi-gram scale synthesis of terphenyl compound.
基金This work was supported by the National Natural Science Foundation of China(30470027 and 30225048)Natural Science Foundation of Yunnan Province(2005C0052Mand 2005C0011R).
