Semiempirical quantum chemical method AM1 was employed to calculate the highest occupied molecular orbital (HOMO) energy levels (E-HOMO) for various types of antioxidants. It was verified that the correlation between ...Semiempirical quantum chemical method AM1 was employed to calculate the highest occupied molecular orbital (HOMO) energy levels (E-HOMO) for various types of antioxidants. It was verified that the correlation between logarithm of free radical scavenging rate constants (1gks) and E-HOMO substantially arises from the correlation between E-HOMO and O-H bond dissociation energies (BDE) of antioxidants. Furthermore, E-HOMO were poorly correlated with the logarithm of relative free radical scavenging rate constants (1gk(3)/k(1)) for various types of antioxidants that possess complex structures (r = 0.5602). So in a broad sense, E-HOMO was not an appropriate parameter to characterize the free radical scavenging activity of antioxidants.展开更多
A novel D-A alternative conjugated polymer PBDTDMCT containing benzo[1,2-b：4,5-b＇]dithiophene （BDT） and dimethyl thiophene-3,4-dicarboxylate （DMCT）, was designed and synthesized by Stille cross-coupling reaction...A novel D-A alternative conjugated polymer PBDTDMCT containing benzo[1,2-b：4,5-b＇]dithiophene （BDT） and dimethyl thiophene-3,4-dicarboxylate （DMCT）, was designed and synthesized by Stille cross-coupling reaction. The copolymer exhibited excellent solubility and good thermal stability. The optical band gap determined from the onset of absorption of the polymer film was 2.10 eV. By incorporation of the ester groups into the polymer side chain, the HOMO level of polymer PBDTDMT was tuned to be deep-lying （--5.65 eV）. Open-circuit voltage of polymer solar cells constructed based on PBDTDMT and [6,6]-phenyl-CTwbutyric acid methyl ester （PCTIBM） can be tuned to achieve values as high as ca. 1.0 V.展开更多
A low band gap acceptor-donor-acceptor （A-D-A） small molecule donor material, named DR3TDTN, has been designed and synthesized for solution-processed organic solar cells. DR3TDTN shows narrow optical band gap with v...A low band gap acceptor-donor-acceptor （A-D-A） small molecule donor material, named DR3TDTN, has been designed and synthesized for solution-processed organic solar cells. DR3TDTN shows narrow optical band gap with value of 1.49 eV and broad absorption spectrum from 300 to 820 rim. The HOMO and LUMO energy levels of DR3TDTN are -4.74 and -3.26 eV, respectively. The optimized photovoltaic device based on DR3TDTN：PC71BM blend film shows a power conversion efficiency of 3.03% with an open-circuit voltage of 0.67 V, a short-circuit current of 8.22 mA·cm^-2 and fill factor of 0.55.展开更多
In this article, we designed and synthesized a series of 5-（2,6-dimethyl-4H-pyran-4-ylidene）-1,3-diethyl-2-thioxodihydropyrimidine-4,6（1H, 5H）-dione（PD） unit based polymers（PFTDT, CZTDT, PHTDT and THTDT） for t...In this article, we designed and synthesized a series of 5-（2,6-dimethyl-4H-pyran-4-ylidene）-1,3-diethyl-2-thioxodihydropyrimidine-4,6（1H, 5H）-dione（PD） unit based polymers（PFTDT, CZTDT, PHTDT and THTDT） for the first time. In these polymers, fluorene, 2,7-carbazole, phenothiazine and thiophene are employed as electron-donating groups and PD as electron-withdrawing group. TGA measurements demonstrated that these polymers possess good thermal stability（all above 377 °C）. Very broad absorption spectrum was also obtained from the polymer THTDT（300？850 nm）. CV characterization found that these polymers owned low highest occupied molecular orbital（HOMO） energy levels（？5.39 e V for THTDT, ？5.49 e V for CZTDT and ？5.78 e V for PFTDT） except for PHTDT（？5.17 e V）. The geometry and electronic properties of PFTDT, CZTDT, PHTDT and THTDT were investigated by means of theoretical calculation. All the above advantages demonstrate that PD based polymers could be candidates for electronic devices.展开更多
文摘Semiempirical quantum chemical method AM1 was employed to calculate the highest occupied molecular orbital (HOMO) energy levels (E-HOMO) for various types of antioxidants. It was verified that the correlation between logarithm of free radical scavenging rate constants (1gks) and E-HOMO substantially arises from the correlation between E-HOMO and O-H bond dissociation energies (BDE) of antioxidants. Furthermore, E-HOMO were poorly correlated with the logarithm of relative free radical scavenging rate constants (1gk(3)/k(1)) for various types of antioxidants that possess complex structures (r = 0.5602). So in a broad sense, E-HOMO was not an appropriate parameter to characterize the free radical scavenging activity of antioxidants.
文摘A novel D-A alternative conjugated polymer PBDTDMCT containing benzo[1,2-b：4,5-b＇]dithiophene （BDT） and dimethyl thiophene-3,4-dicarboxylate （DMCT）, was designed and synthesized by Stille cross-coupling reaction. The copolymer exhibited excellent solubility and good thermal stability. The optical band gap determined from the onset of absorption of the polymer film was 2.10 eV. By incorporation of the ester groups into the polymer side chain, the HOMO level of polymer PBDTDMT was tuned to be deep-lying （--5.65 eV）. Open-circuit voltage of polymer solar cells constructed based on PBDTDMT and [6,6]-phenyl-CTwbutyric acid methyl ester （PCTIBM） can be tuned to achieve values as high as ca. 1.0 V.
文摘A low band gap acceptor-donor-acceptor （A-D-A） small molecule donor material, named DR3TDTN, has been designed and synthesized for solution-processed organic solar cells. DR3TDTN shows narrow optical band gap with value of 1.49 eV and broad absorption spectrum from 300 to 820 rim. The HOMO and LUMO energy levels of DR3TDTN are -4.74 and -3.26 eV, respectively. The optimized photovoltaic device based on DR3TDTN：PC71BM blend film shows a power conversion efficiency of 3.03% with an open-circuit voltage of 0.67 V, a short-circuit current of 8.22 mA·cm^-2 and fill factor of 0.55.
基金financially supported by the Research Program of 973 Program(No.2014CB643506)the National Natural Science Foundation of China(No.21401053)+2 种基金Project of Scientific Research and Development of Xiangyang(Year of 2013)Open Foundation of Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices(HLOM141003)Opening Project of Guangxi Colleges and Universities Key Laboratory of Beibu Gulf Oil and Natural Gas Resource Effective Utilization(No.2014KLOG03)
文摘In this article, we designed and synthesized a series of 5-（2,6-dimethyl-4H-pyran-4-ylidene）-1,3-diethyl-2-thioxodihydropyrimidine-4,6（1H, 5H）-dione（PD） unit based polymers（PFTDT, CZTDT, PHTDT and THTDT） for the first time. In these polymers, fluorene, 2,7-carbazole, phenothiazine and thiophene are employed as electron-donating groups and PD as electron-withdrawing group. TGA measurements demonstrated that these polymers possess good thermal stability（all above 377 °C）. Very broad absorption spectrum was also obtained from the polymer THTDT（300？850 nm）. CV characterization found that these polymers owned low highest occupied molecular orbital（HOMO） energy levels（？5.39 e V for THTDT, ？5.49 e V for CZTDT and ？5.78 e V for PFTDT） except for PHTDT（？5.17 e V）. The geometry and electronic properties of PFTDT, CZTDT, PHTDT and THTDT were investigated by means of theoretical calculation. All the above advantages demonstrate that PD based polymers could be candidates for electronic devices.
