Mariappan Kadarkaraisamy, Alaparthi Madhubabu, Caple Gerald, Balasubramanian Vinothini, Hoffman Mariah M, Hudspeth Mikaela, Sykes Andrew G
The Department of Chemistry, University of South Dakota , Vermillion, South Dakota 57069, United States.
Inorg Chem. 2014 Mar 17;53(6):2953-62. doi: 10.1021/ic402723c. Epub 2014 Mar 6.
Addition of hydrazines to a 1,8-disubstituted anthraquinone macrocycle containing a polyether ring produces site-selective imination, where hydrazone formation produces the more sterically hindered adduct. Reduction of the remaining carbonyl group to a secondary alcohol followed by addition of copper(II) ion causes intense yellow fluorescence to occur, which is selective for this metal cation and allows this system to be used as a fluorescence sensor. In the presence of water, a green-fluorescent intermediate appears, which slowly decomposes to produce the original starting anthraquinone. The addition of a large amount of water radically changes the reaction pathway. In this case, oxidation of the secondary alcohol is kinetically faster than hydrolysis of the hydrazone, although the same anthraquinone product is ultimately produced. Stern-Volmer data suggest that dioxygen quenches the green emission through both dynamic and static mechanisms; the static ground-state effect is most likely due to association of oxygen with the copper-bound fluorescent intermediate.
将肼添加到含有聚醚环的1,8 - 二取代蒽醌大环中会产生位点选择性亚胺化反应，其中腙的形成会生成空间位阻更大的加合物。将剩余的羰基还原为仲醇，然后加入铜（II）离子会产生强烈的黄色荧光，这种荧光对该金属阳离子具有选择性，使得该体系可作为荧光传感器使用。在有水存在的情况下，会出现绿色荧光中间体，它会缓慢分解生成原始的起始蒽醌。加入大量水会从根本上改变反应途径。在这种情况下，仲醇的氧化在动力学上比腙的水解更快，尽管最终会生成相同的蒽醌产物。斯特恩 - 沃尔默数据表明，氧气通过动态和静态机制猝灭绿色发射；静态基态效应最有可能是由于氧气与铜结合的荧光中间体缔合所致。
