We report that the ultraviolet （UV） light induced photochromic behavior of layered organic-inorganic perovskite material of （C4H9NH3）2CuCl4, changed from yellow to brown after irradiation with UV light （10 mW/cm^...We report that the ultraviolet （UV） light induced photochromic behavior of layered organic-inorganic perovskite material of （C4H9NH3）2CuCl4, changed from yellow to brown after irradiation with UV light （10 mW/cm^2） and partially recovered through storage in the dark. （C4H9NH3）2CuCl4 exhibited two distinct absorption bands centered at 286 nm （band Ⅰ） and 384 nm （band Ⅱ）, which were attributed to the photo-induced exciton formed in 2D inorganic layers sandwiched by organic layers. The blue shift of band Ⅰ from 287 to 269 nm as well as the decrease of the intensity of band Ⅰ and band Ⅱ could be found when samples were irradiated under UV light for different length of time. The simultaneous weakening of the intensity of the N-H...Cl hydrogen bond as well as the vibration of the long Cu-Cl bond in the distorted CuCl6^4- octahedron could be detected from the Fourier transform infrared （FTIR） spectra, which resulted the change of charge distribution of the dissymmetric Cl-Cu...Cl bond and the resulting photochromic behavior.展开更多
A series of new polyamides 3a-d containing aryl-azo, ether and sulfone groups in the main chain were synthesized from bis[4-（4-aminophenoxy）phenyl sulfone] 1 and several azo aromatic diacyl chlorides 2a-d by the low...A series of new polyamides 3a-d containing aryl-azo, ether and sulfone groups in the main chain were synthesized from bis[4-（4-aminophenoxy）phenyl sulfone] 1 and several azo aromatic diacyl chlorides 2a-d by the low temperature solution polycondensation technique. FTIR spectroscopy, nuclear magnetic resonance （NMR） and elemental analyses confirmed the structure of these polymers. Owing to the aryl and amide groups in the main chain, these polymers exhibit photochromic properties as well as excellent thermal stabilities. The transition temperatures （Tg） are between 242 and 265℃, and the char yields at 800 ℃ in nitrogen atmosphere were above 39%. Based on incorporation of flexible ether linkages and polar sulfone groups, the polyamides show desirable solubility in organic solvents such as DMAc, N,N-dimethylformamide （DMF）, N-methyl-2-pyrroidinone （NMP） and dimethylsulfoxide （DMSO）. And it is exemplified that polyamide containing 2 and 2＇ substitutes performed better solubility.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 50318001, 50433020, 50503021 and 50520150165)the Developing Program of Changjiang Scholar and Innovation Team from Ministry of Education of China (No. IRT0651)
文摘We report that the ultraviolet （UV） light induced photochromic behavior of layered organic-inorganic perovskite material of （C4H9NH3）2CuCl4, changed from yellow to brown after irradiation with UV light （10 mW/cm^2） and partially recovered through storage in the dark. （C4H9NH3）2CuCl4 exhibited two distinct absorption bands centered at 286 nm （band Ⅰ） and 384 nm （band Ⅱ）, which were attributed to the photo-induced exciton formed in 2D inorganic layers sandwiched by organic layers. The blue shift of band Ⅰ from 287 to 269 nm as well as the decrease of the intensity of band Ⅰ and band Ⅱ could be found when samples were irradiated under UV light for different length of time. The simultaneous weakening of the intensity of the N-H...Cl hydrogen bond as well as the vibration of the long Cu-Cl bond in the distorted CuCl6^4- octahedron could be detected from the Fourier transform infrared （FTIR） spectra, which resulted the change of charge distribution of the dissymmetric Cl-Cu...Cl bond and the resulting photochromic behavior.
基金Funded by the National Natural Science Foundation of China (No.50572081)
文摘A series of new polyamides 3a-d containing aryl-azo, ether and sulfone groups in the main chain were synthesized from bis[4-（4-aminophenoxy）phenyl sulfone] 1 and several azo aromatic diacyl chlorides 2a-d by the low temperature solution polycondensation technique. FTIR spectroscopy, nuclear magnetic resonance （NMR） and elemental analyses confirmed the structure of these polymers. Owing to the aryl and amide groups in the main chain, these polymers exhibit photochromic properties as well as excellent thermal stabilities. The transition temperatures （Tg） are between 242 and 265℃, and the char yields at 800 ℃ in nitrogen atmosphere were above 39%. Based on incorporation of flexible ether linkages and polar sulfone groups, the polyamides show desirable solubility in organic solvents such as DMAc, N,N-dimethylformamide （DMF）, N-methyl-2-pyrroidinone （NMP） and dimethylsulfoxide （DMSO）. And it is exemplified that polyamide containing 2 and 2＇ substitutes performed better solubility.
