共查询到20条相似文献,搜索用时 15 毫秒
1.
《Macromolecular rapid communications》2017,38(22)
Organic solar cells based on semiconducting polymers and small molecules have attracted considerable attention in the last two decades. Moreover, the power conversion efficiencies for solution‐processed solar cells containing A–π–D–π–A‐type small molecules and fullerenes have reached 11%. However, the method for designing high‐performance, photovoltaic small molecules still remains unclear. In this review, recent studies on A–π–D–π–A electron‐donating small molecules for organic solar cells are introduced. Moreover, the relationships between molecular properties and device performances are summarized, from which inspiration for the future design of high performance organic solar cells may be obtained. 相似文献
2.
Yu Zhang Ying‐Tong Di Hai‐Yang Liu Chun‐Shun Li Cheng‐Jian Tan Qiang Zhang Xin Fang Shun‐Lin Li Xiao‐Jiang Hao 《Helvetica chimica acta》2008,91(11):2153-2158
Nine Daphniphyllum alkaloids, including three new ones, paxiphyllines C–E ( 1 – 3 , resp.), were isolated from the twigs and the leaves of Daphniphyllum paxianum. Paxiphylline C ( 1 ) represents the first example of Daphniphyllum alkaloids with a carbonyldioxy group. Their structures were elucidated on the basis of spectroscopic data. 相似文献
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A phytochemical investigation of the BuOH‐soluble fraction of the EtOH extract from the stems of Glycosmis pentaphylla resulted in the isolation of three new phenolic glycosides, glycopentosides D–F ( 1 – 3 , resp.). Their structures were determined by using spectroscopic analysis including UV, 1H‐ and 13C‐NMR, DEPT, COSY, ROESY, HMBC, HSQC, HR‐ESI‐MS, and acid hydrolysis. 相似文献
5.
Muhammad Aijaz Anwar Shazia Yasmeen Sadia Ferheen Nighat Afza Abdul Malik Mahboob Ali Kalhoro 《Helvetica chimica acta》2013,96(9):1801-1806
Three new isomeric biisoflavonoids, dapholidins A–C ( 1 – 3 , resp.), have been isolated from the AcOEt‐soluble fraction of the MeOH‐soluble extract of the roots of Daphne oleoides, along with the known compounds daphwazirin ( 4 ), daphnetin 8‐O‐β‐D ‐glucopyranoside ( 5 ), daphnin ( 6 ), daphneticin 4″‐O‐β‐D ‐glucopyranoside ( 7 ), and 6,7‐dihydroxy‐3‐methoxy‐8‐[2‐oxo‐2H‐1‐benzopyran‐7‐(O‐β‐D ‐glucopyranosyl)‐8‐yl]‐2H‐1‐benzopyran‐2‐one ( 8 ). The structures of the new compounds were determined by spectroscopic analyses, including 1D‐ and 2D‐NMR. 相似文献
6.
Guo‐You Li Li‐Mei Li Tao Yang Xiao‐Zhen Chen Dong‐Mei Fang Guo‐Lin Zhang 《Helvetica chimica acta》2010,93(10):2075-2080
Four new alkaloids, brevianamides O–R ( 1 – 4 , resp.), were isolated from the AcOEt extract of the solid‐state fermented rice culture of the fungus Aspergillus versicolor. Their structures were elucidated on the basis of spectroscopic analyses. 相似文献
7.
Heqing Tang Lihua Zhu Yutaka Harima Kazuo Yamashita Joji Ohshita Atsutaka Kunai 《Journal of Polymer Science.Polymer Physics》1999,37(15):1873-1880
UV‐visible absorption and fluorescence properties of three series of σ–π‐conjugated polymers (copolymers of alternative oligothienylene and oligosilylene units) have been studied in dioxane solution. The energies of the absorption maximum, fluorescence maximum, and the 0–0 transition are found to be linearly dependent on the reciprocal of the number of thiophene rings in the repeating unit of the polymer chain, but almost independent of the silicon atom number. The σ–π‐conjugation in the polymers results in red shift in the absorption and fluorescence maxima, higher fluorescence quantum yields, and longer fluorescence lifetimes of the polymers, with respect to their corresponding analogous α‐oligothiophenes. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 1873–1880, 1999 相似文献
8.
Dimorphamides A–C ( 1 – 3 , resp.), three new polyphenolic amides, have been isolated from the BuOH‐soluble fraction of the whole plant of Atriplex dimorphostagia, along with two known compounds, thymidine and N‐[(E)‐feruloyl]tyramine. Their structures have been determined on the basis of spectral studies. 相似文献
9.
Dr. Koji Yamamoto Seita Kimura Prof. Tetsuro Murahashi 《Angewandte Chemie (International ed. in English)》2016,55(17):5322-5326
The intrinsic features of (hetero‐arene)–metal interactions have been elusive mainly because the systematic structure analysis of non‐anchored hetero‐arene–metal complexes has been hampered by their labile nature. We report successful isolation and systematic structure analysis of a series of non‐anchored indole–palladium(II) complexes. It was revealed that there is a σ–π continuum for the indole–metal interaction, while it has been thought that the dominant coordination mode of indole to a metal center is the Wheland‐intermediate‐type σ‐mode in light of the seemingly strong electron‐donating ability of indole. Several factors which affect the σ‐ or π‐character of indole–metal interactions are discussed. 相似文献
10.
Ya‐Ching Shen Yun‐Sheng Lin Shaw‐Man Hsu Ashraf Taha Khalil Shih‐Sheng Wang Ching‐Te Chien Yao‐Haur Kuo Chang‐Hung Chou 《Helvetica chimica acta》2007,90(7):1319-1329
The phytochemical investigation of the more polar fractions from the leaves and twigs of Taxus sumatrana (Taxaceae) afforded five new taxane diterpene esters, tasumatrols P–T ( 1 – 5 ) possessing an 11(15→1),11(10→9)‐diabeotaxane skeleton. Compounds 1, 4 , and 5 contain an α‐hydroxy group at C(14), while 3 has no OH group at either C(13) or C(14). Compound 2 is a natural 4,5‐acetonide derivative, while 4 has an unusual spiro‐connected 2‐hydroxy‐2‐phenyl‐1,3‐dioxolane ring. Ten known taxoids, were also isolated in the course of the chromatographic fractionation. Five additional new O‐acetyl derivatives 3a, 4a, 4b, 5a , and 5b were prepared from the taxanes 3 – 5 . The structures of all new compounds were established on the basis of their spectroscopic analyses. Compound 1 showed mild cytotoxic activity against human Hela and Daoy tumor cells. 相似文献
11.
Xing‐Yun Chai Zheng‐Ren Xu Hong‐Yan Ren Hai‐Ming Shi Ya‐Nan Lu Fei‐Fei Li Peng‐Fei Tu 《Helvetica chimica acta》2007,90(11):2176-2185
Eight new benzoylated gentisyl alcohol (=2‐(hydroxymethyl)benzene‐1,4‐diol) glucosides, itosides A–H ( 1 – 8 ), together with the new pyrocatechol (=benzene‐1,2‐diol) glycoside itoside I ( 9 ) were isolated from the bark and twigs of Itoa orientalis (Flacourtiaceae). In itosides B–D ( 2 – 4 ), the gentisyl alcohol moiety was esterified by 1‐hydroxy‐6‐oxocyclohex‐2‐ene‐1‐carboxylic acid, while itosides E–H ( 5 – 8 ) contained instead an additional 2‐hydroxybenzoic acid moiety. The compounds were accompanied by the known derivatives 4‐hydroxytremulacin ( 10 ), poliothyrsoside ( 11 ), poliothyrsin ( 12 ), homaloside D ( 13 ), tremulacin, and pyrocatechol β‐D ‐glucopyranoside. The structures of the new compounds were elucidated by spectral and chemical methods. 相似文献
12.
Bakhat Ali Rashad Mehmood Uzma Rasheed Mughal Abdul Malik Muhammad Safder Riaz Hussain Muhammad Imran Rasool Bakhsh Tareen 《Helvetica chimica acta》2012,95(4):586-593
Eremosides A–C ( 1 – 3 ), three new iridoid glucosides, were isolated from the AcOEt‐soluble fraction of the EtOH extract of the whole plant of Eremostachys loasifolia, along with buddlejoside B ( 4 ), 10‐O‐benzoylcatalpol ( 5 ), and pakiside A ( 6 ) reported for the first time from this species. The structures of these compounds were elucidated by spectroscopic data including 2D‐NMR, FAB‐MS, ESI‐MS, as well as by acid and basic hydrolyses. 相似文献
13.
Six new compounds, phochinenins A–F ( 1 – 6 ), dimerized from 9,10‐dihydrophenanthrene and dihydrostilbene through direct coupling or an oxygen bridge, along with eight known compounds, were isolated from the whole plants of Pholidota chinensis. Their structures were elucidated on the basis of extensive spectroscopic investigations (1D‐, 2D‐NMR, and HR‐EI‐MS). 相似文献
14.
Photophysical Properties of Intramolecular Charge Transfer in a Tribranched Donor–π–Acceptor Chromophore 下载免费PDF全文
Jiangpu Hu Yang Li Huaning Zhu Shuhai Qiu Guiying He Prof. Xiaozhang Zhu Prof. Andong Xia 《Chemphyschem》2015,16(11):2357-2365
The photophysical properties of intramolecular charge transfer (ICT) in a novel tribranched donor–π–acceptor chromophore, triphenoxazine‐2,4,6‐triphenyl‐1,3,5‐triazine (tri‐PXZ‐TRZ), with thermally activated delayed fluorescence character was investigated in different aprotic solvents by steady‐state spectroscopy and femtosecond and nanosecond transient absorption spectroscopy measurements. Increasing the solvent polarity led to a significant increase in the Stokes shift. The large Stokes shift in highly polar solvents was attributed to ICT properties upon excitation; this resulted in a strong interaction between the tri‐PXZ‐TRZ molecule and the surrounding solvent, which led to a strong solvation process. Quantum‐chemical calculations and changes in the dipole moment showed that this compound has a large degree of ICT. Furthermore, an apolar environment helped to preserve the symmetry of tri‐PXZ‐TRZ and to enhance its emission efficiency. The femtosecond and nanosecond transient absorption spectroscopy results indicated that the excited‐state dynamics of this push–pull molecule were strongly influenced by solvent polarity through the formation of a solvent‐stabilized ICT state. The excited‐state relaxation mechanism of tri‐PXZ‐TRZ was proposed by performing target model analysis on the femtosecond transient absorption spectra. In addition, the delayed fluorescence of tri‐PXZ‐TRZ was significantly modulated by a potential competition between solvation and intersystem crossing processes. 相似文献
15.
Brigida D'Abrosca Severina Pacifico Monica Scognamiglio Nikolaos Tsafantakis Emanuela Pagliari Pietro Monaco Antonio Fiorentino 《Helvetica chimica acta》2013,96(7):1273-1280
Four novel γ‐pyrone (=4H‐pyran‐4‐one) metabolites, petrorhagiosides A–D, along with four known analogs, have been isolated from the MeOH extract of Petrorhagia saxifraga, a perennial herbaceous plant typical of Mediterranean vegetation. The structures of the new compounds were established on the basis of extensive spectroscopic analyses including 1D‐ an 2D‐NMR (1H,1H‐DQ‐COSY, TOCSY, HSQC, CIGAR‐HMBC, and HSQC‐TOCSY) experiments. 相似文献
16.
Zheng‐Hong Pan Jin‐Tang Cheng Juan He Yuan‐Yuan Wang Li‐Yan Peng Gang Xu Wei‐Bang Sun Qin‐Shi Zhao 《Helvetica chimica acta》2011,94(3):417-422
Three new clerodane diterpenoids, splendidins A–C ( 1 – 3 , resp.), were isolated from Salvia splendens, together with six known ones. Their structures were elucidated by extensive spectroscopic analysis. Splendidin C ( 3 ) was the first diterpenoid glucoside reported from this plant. These compounds were evaluated for their cytotoxic activity; however, none of them were cytotoxic. 相似文献
17.
Three new monoterpenoid indole alkaloids, vinmajorines C–E ( 1 – 3 ), along with 18 known analogues ( 4 – 21 ), were isolated from the whole plants of Vinca major. The new structures were elucidated as (5α,15β,16R,17α,19β,20α,21β)‐10,17‐dimethoxy‐21‐methyl‐18‐oxa‐5,16‐cycloyohimban‐19‐ol ( 1 ), (5α,15β,16R,17α,20α,21β)‐10‐methoxy‐21‐methyl‐18‐oxa‐5,16‐cycloyohimban‐17‐ol ( 2 ), and (5α,15β,16R,17α,20α,21β)‐10‐methoxy‐21‐methyl‐18‐oxa‐5,16‐cycloyohimban‐17‐yl acetate ( 3 ), respectively, by extensive NMR and MS analysis and comparison with known compounds. Compounds 1 – 3 were evaluated for their cytotoxic activities against five human cancer cell lines, compounds 1 and 3 showing moderate cytotoxic activities. 相似文献
18.
Fuminori Hiramatsu Tetsuya Murayama Takuya Koseki Katsuhide Okada Yoshihito Shiono 《Helvetica chimica acta》2008,91(8):1595-1603
New cadinane sequiterpenoids, strobilols E–K ( 5 – 11 , resp.) have been isolated from a liquid culture of Strobilurus ohshimae. Their structures have been established on the basis of spectral analyses. 相似文献
19.
Zheng‐Ren Xu Xing‐Yun Chai Chang‐Cai Bai Hong‐Yan Ren Ya‐Nan Lu Hai‐Ming Shi Peng‐Fei Tu 《Helvetica chimica acta》2008,91(7):1346-1354
Seven new phenolic glucosides, xylocosides A–G ( 1 – 7 ), together with 18 known compounds were isolated from the stems of Xylosma controversum Clos . In compounds 3 – 6 , the glucose residue is esterified at C(6) by 2‐hydroxycyclopentanecarboxylic acid. These new structures were established by spectroscopic‐data interpretation and chemical methods. 相似文献
20.
Ya‐Ching Shen Pei‐Show Shih Yun‐Sheng Lin Yu‐Chi Lin Yao‐Haur Kuo Yuh‐Chi Kuo Ashraf Taha Khalil 《Helvetica chimica acta》2009,92(10):2101-2110
Chemical investigation of the sponge Ircinia formosana resulted in the isolation of seven new linear C22‐sesterterpenoids, irciformonins E–K ( 1 – 7 ) in addition to irciformonin A ( 8 ), a previously isolated furanosesterterpenoid (=a furan‐moiety‐containing sesterterpenoid) from the same species. The structures were determined by interpretation of HR‐ESI‐MS and 2D‐NMR spectra. The structure of irciformonin A ( 8 ) was revised. Compound 5 exhibited significant inhibition of peripheral blood mononuclear cell proliferation induced by phytohemaglutinin. 相似文献