Bifunctional pyrazoline derivatives 5 and 6 containing azobenzene group were prepared. The difference between them was the length of the flexible chain connecting the two chromophores. Compound 6 had four more methyle...Bifunctional pyrazoline derivatives 5 and 6 containing azobenzene group were prepared. The difference between them was the length of the flexible chain connecting the two chromophores. Compound 6 had four more methylenes than compound 5. UV\|Vis spectra of compounds 5 and 6 were the simple superposition of the absorbance of the azobenzene and pyrazoling and showed that pyrazoline had no effect on the isomerization of azobenzene. When there were two methylenes between azobenzene and pyrazoline, the fluorescent intensity of compound 5 decreased greatly compared with that of compound 6. It means that the intramolecular Electronic Energy Transfer has taken place in compound 5. In compound 6, this process could not occur because of the longer flexible chain between the two chromophores.展开更多
Three azo-dyes, 4′-{[(2-hydroxylethyl)methyl]amino}-4-nitroazobenzene(1), 1-[4-(4′-nitrophenyl)-azophenyl]-3,5-biphenyl-2-pyrazoline(2) and 1-[4-(4′-nitrophenyl)-azophenyl]-5-(4′-hydroxylphenyl)-3-phenyl-2-pyrazol...Three azo-dyes, 4′-{[(2-hydroxylethyl)methyl]amino}-4-nitroazobenzene(1), 1-[4-(4′-nitrophenyl)-azophenyl]-3,5-biphenyl-2-pyrazoline(2) and 1-[4-(4′-nitrophenyl)-azophenyl]-5-(4′-hydroxylphenyl)-3-phenyl-2-pyrazoline(3) were synthesized. The polarized photoinduced birefringence and relaxation process of those azo-dyes doped with PMMA films were investigated under polarized laser intensity. The results indicate that compounds with pyrazoline group have a high storage rate and thermal stability. It has been found that the birefringence signals decrease with the increase of the temperature, but the effect of temperature is different for the three compounds. Compounds 2 and 3, with pyrazoline groups have a good thermal stability at room temperature, and compound 3 can even keep 30% of its maximum birefringence at 90 ℃.展开更多
In this paper, the SERRS of BATD has been investigated, the effect of pH,concentration and electrolyte on SERRS was discussed and the adsorbed state of BTADwas figured. We suggest that the adsorbed state of BTAD is th...In this paper, the SERRS of BATD has been investigated, the effect of pH,concentration and electrolyte on SERRS was discussed and the adsorbed state of BTADwas figured. We suggest that the adsorbed state of BTAD is the bonding of benzotriazolto Ag surface via lone palr electron on the nitrogen. With HCl and ascorbic acid aggre-gate Ag sol, the dependence of SERRS on BTAD concentration behaves differently. Inthe former case, the adsorbed state changes, but in the latter it remains the same. Smallamount of electrolyte will induce the active sites on the surface, but when it is more than1×102zmol L-1, the competent adsorbtion reduces the Ratnan scattering intensity. Hy-drogen ions protonize BTAD to BTAHD and reduce the contribution of lone pair electronon N atom of the conjugated system.展开更多
The synthesis of new chromogenic p (o,m,p carboxylazo)Calixarenes derivatives through the couping of diazotized o,m,p aminobenzene carboxylic acid and calixarenes was described.Their structures were comfirmed by IR, 1...The synthesis of new chromogenic p (o,m,p carboxylazo)Calixarenes derivatives through the couping of diazotized o,m,p aminobenzene carboxylic acid and calixarenes was described.Their structures were comfirmed by IR, 1H NMR and elemental analysis.Their chromogenic properties and UV Vis absorption spectra were investigated under different pH conditions.Experimental results show that the synthesized derivatives can be used as new indicators and host展开更多
文摘Bifunctional pyrazoline derivatives 5 and 6 containing azobenzene group were prepared. The difference between them was the length of the flexible chain connecting the two chromophores. Compound 6 had four more methylenes than compound 5. UV\|Vis spectra of compounds 5 and 6 were the simple superposition of the absorbance of the azobenzene and pyrazoling and showed that pyrazoline had no effect on the isomerization of azobenzene. When there were two methylenes between azobenzene and pyrazoline, the fluorescent intensity of compound 5 decreased greatly compared with that of compound 6. It means that the intramolecular Electronic Energy Transfer has taken place in compound 5. In compound 6, this process could not occur because of the longer flexible chain between the two chromophores.
文摘Three azo-dyes, 4′-{[(2-hydroxylethyl)methyl]amino}-4-nitroazobenzene(1), 1-[4-(4′-nitrophenyl)-azophenyl]-3,5-biphenyl-2-pyrazoline(2) and 1-[4-(4′-nitrophenyl)-azophenyl]-5-(4′-hydroxylphenyl)-3-phenyl-2-pyrazoline(3) were synthesized. The polarized photoinduced birefringence and relaxation process of those azo-dyes doped with PMMA films were investigated under polarized laser intensity. The results indicate that compounds with pyrazoline group have a high storage rate and thermal stability. It has been found that the birefringence signals decrease with the increase of the temperature, but the effect of temperature is different for the three compounds. Compounds 2 and 3, with pyrazoline groups have a good thermal stability at room temperature, and compound 3 can even keep 30% of its maximum birefringence at 90 ℃.
文摘In this paper, the SERRS of BATD has been investigated, the effect of pH,concentration and electrolyte on SERRS was discussed and the adsorbed state of BTADwas figured. We suggest that the adsorbed state of BTAD is the bonding of benzotriazolto Ag surface via lone palr electron on the nitrogen. With HCl and ascorbic acid aggre-gate Ag sol, the dependence of SERRS on BTAD concentration behaves differently. Inthe former case, the adsorbed state changes, but in the latter it remains the same. Smallamount of electrolyte will induce the active sites on the surface, but when it is more than1×102zmol L-1, the competent adsorbtion reduces the Ratnan scattering intensity. Hy-drogen ions protonize BTAD to BTAHD and reduce the contribution of lone pair electronon N atom of the conjugated system.
文摘The synthesis of new chromogenic p (o,m,p carboxylazo)Calixarenes derivatives through the couping of diazotized o,m,p aminobenzene carboxylic acid and calixarenes was described.Their structures were comfirmed by IR, 1H NMR and elemental analysis.Their chromogenic properties and UV Vis absorption spectra were investigated under different pH conditions.Experimental results show that the synthesized derivatives can be used as new indicators and host
