Nickel(II) Dithiocarbamate Complexes Containing Sulforhodamine B as Fluorescent Probes for Selective Detection of Nitrogen Dioxide

We synthesized complexes of Ni­(II) with dithiocarbamate ligands derived from the ortho and para isomers of sulforhodamine B fluorophores and demonstrated they are highly selective in reactions with nitrogen dioxide (NO2). Compared with the para isomer, the ortho isomer showed a much greater fluorescence increase upon reaction with NO2, which led to oxidation and decomplexation of the dithiocarbamate ligand from Ni­(II). We applied this probe for visual detection of 1 ppm NO2 in the gas phase and fluorescence imaging of NO2 in macrophage cells treated with a nitrogen dioxide donor.本研究合成了由磺酰罗丹明B（sulforhodamine B）荧光染料邻位与对位异构体衍生的二硫代氨基甲酸酯配体与镍(II)（Ni(II)）形成的配合物，并证实此类配合物与二氧化氮（NO₂）的反应具有极高选择性。相较于对位异构体，邻位异构体与NO₂反应后荧光强度增幅更为显著，该反应会引发二硫代氨基甲酸酯配体被氧化并从Ni(II)上发生脱配。我们将该探针应用于气相中1 ppm浓度NO₂的可视化检测，以及经二氧化氮供体处理的巨噬细胞内NO₂的荧光成像实验。