The photochemistry of azo dyes. Photoisomerisation versus photoreduction from 4-diethylaminoazobenzene and 4-diethylamino-4′-methoxyazobenzene
作者:Angelo Albini、Elisa Fasani、Silvio Pietra
DOI:10.1039/p29830001021
日期:——
4-Diethylaminoazobenzene (2) and 4-diethylamino-4′-methoxyazobenzene (3) undergo geometrical isomerization with a quantum yield of almost unity by irradiation in the visible region, and, with lower efficiency, by irradiation at a shorter wavelength or sensitization both with high and low energy hydrocarbons. These dyes are also photoreduced, this time however only by irradiation at λ⩽ 313 nm and with
4-二乙基氨基偶氮苯(2)和4-二乙基氨基-4'-甲氧基偶氮苯(3)通过在可见光区进行辐照进行几何异构化,其量子产率几乎为1,而在较短波长下进行辐照或敏化则效率较低。与高和低能量的碳氢化合物。这些染料也光还原,此时然而仅通过在照射λ ⩽313 nm和具有低量子产率(10 -4 -4×10 -2)。光还原还通过高能敏化剂的能量转移以及酮的自由基引发而发生。结论是,这些偶氮苯衍生物的最低单重态和三重态是商业上可用的单偶氮染料的合理模型,它们仅能够进行几何异构化,而氢的提取则是由反式-和独联体这些染料的构型。