Prophyra-334 was prepared by methanol extraction and HPLC methods from marine algae （dried laver）. It is a sunscreen compound that has good absorption of ultraviolet radiations in the wavelength ranges of 200-400 nm...Prophyra-334 was prepared by methanol extraction and HPLC methods from marine algae （dried laver）. It is a sunscreen compound that has good absorption of ultraviolet radiations in the wavelength ranges of 200-400 nm. The absorption maximum wavelength of prophyra-334 is at 334 nm, so defined the name. The molar extinction coefficient （ε） of prophyra-334 in aqueous solution at 334 nm wavelength is 4.23×10^4. The absorption of prophyra-334 in organic solvents differs in aqueous solutions. In polar organic solvents, the absorption maximum wavelength of prophyra-334 has a slight shift toward longer wavelength compared with that in pure water. On the contrary, in inert non-polar organic solvents, the absorption maximum wavelength and the shape of absorption spectra of prophyra-334 are changed. The effects of organic solvents on prophyra-334 stability suggested that： （1） the absorbance of prophyra-334 in water is generally constant at temperature of 60℃ in 24 h, meaning that prophyra-334 is quite stable in water; （2） the absorbance of prophyra-334 in ethanol and hexane decreases at the same condition. The stability of prophyra-334 in organic solvents is less than that in aqueous solution. In benzene, the prophyra-334 is very instable.展开更多
In order to enlarge the use of coal tar pitch(CTP) in paving road,CTP and 60th paving pitch (PP) were extracted by n-heptane,toluene and ethanol step by step in a Soxhlet apparatus.The three fractions of CTP and PP we...In order to enlarge the use of coal tar pitch(CTP) in paving road,CTP and 60th paving pitch (PP) were extracted by n-heptane,toluene and ethanol step by step in a Soxhlet apparatus.The three fractions of CTP and PP were detected using UV-absorption(UV-A),elemental analyses(EA) and nuclear magnetic resonance(NMR) firstly as a whole unit after quality characterization of physical nature of CTP and PP were finished.The CTP had more saturate aliphatic and residue compounds dissolved in ethanol.On the other hand there were more continental type structures of aromatic ring than that of PP.There was almost no residue in PP after extracted by ethanol.The results explained why CTP was crisp in cold winter and was soften in summer.The following research will focus on how to change the chemical construction of CTP into the relative similar structures with those of PP through adding polymer.展开更多
A series of spiropyrans with a polyaromatic or heteroaromatic pendant was synthesized conveniently. Their photochromic behaviors were investigated with the aid of absorption spectral measurements. The results indicate...A series of spiropyrans with a polyaromatic or heteroaromatic pendant was synthesized conveniently. Their photochromic behaviors were investigated with the aid of absorption spectral measurements. The results indicated that the compounds with the same parent spiropyran but different aromatic pendant show significantly different photochromic properties. This may be due to the π-π orbital interaction between the polyaromatic pendant and the open photomerocyanine form of spiropyran. The results obtained are very useful in the molecule design area.展开更多
基金This study was supported by SRF for ROCS, SEM and Natural ScienceFoundation of Qingdao (No. 04-2-JZ-110)
文摘Prophyra-334 was prepared by methanol extraction and HPLC methods from marine algae （dried laver）. It is a sunscreen compound that has good absorption of ultraviolet radiations in the wavelength ranges of 200-400 nm. The absorption maximum wavelength of prophyra-334 is at 334 nm, so defined the name. The molar extinction coefficient （ε） of prophyra-334 in aqueous solution at 334 nm wavelength is 4.23×10^4. The absorption of prophyra-334 in organic solvents differs in aqueous solutions. In polar organic solvents, the absorption maximum wavelength of prophyra-334 has a slight shift toward longer wavelength compared with that in pure water. On the contrary, in inert non-polar organic solvents, the absorption maximum wavelength and the shape of absorption spectra of prophyra-334 are changed. The effects of organic solvents on prophyra-334 stability suggested that： （1） the absorbance of prophyra-334 in water is generally constant at temperature of 60℃ in 24 h, meaning that prophyra-334 is quite stable in water; （2） the absorbance of prophyra-334 in ethanol and hexane decreases at the same condition. The stability of prophyra-334 in organic solvents is less than that in aqueous solution. In benzene, the prophyra-334 is very instable.
基金Supported by the Progress Plan of Science & Technology of Wuhan Pingmei Wugang Unite Coking Chemical Corp.Ltd,Ltd.of WISCO(2008Z012)
文摘In order to enlarge the use of coal tar pitch(CTP) in paving road,CTP and 60th paving pitch (PP) were extracted by n-heptane,toluene and ethanol step by step in a Soxhlet apparatus.The three fractions of CTP and PP were detected using UV-absorption(UV-A),elemental analyses(EA) and nuclear magnetic resonance(NMR) firstly as a whole unit after quality characterization of physical nature of CTP and PP were finished.The CTP had more saturate aliphatic and residue compounds dissolved in ethanol.On the other hand there were more continental type structures of aromatic ring than that of PP.There was almost no residue in PP after extracted by ethanol.The results explained why CTP was crisp in cold winter and was soften in summer.The following research will focus on how to change the chemical construction of CTP into the relative similar structures with those of PP through adding polymer.
文摘A series of spiropyrans with a polyaromatic or heteroaromatic pendant was synthesized conveniently. Their photochromic behaviors were investigated with the aid of absorption spectral measurements. The results indicated that the compounds with the same parent spiropyran but different aromatic pendant show significantly different photochromic properties. This may be due to the π-π orbital interaction between the polyaromatic pendant and the open photomerocyanine form of spiropyran. The results obtained are very useful in the molecule design area.
