A novel rare-earth nitronyl nitroxide radical complex as a high-efficiency sensor for Cr3+ and Cr2O72− ions in aqueous solutions

In this article, a new complex with formula [Eu(hfac)3(NITPh-DOMe)2] (1) (hfac = hexafluoroacetylacetonate, NITPh-DOMe =2-(3′,4′-dioxylmethylene-phenyl)-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide) has been successfully synthesized. Central Eu(III) ions of complex 1 are eight coordinated by two NITPh-DOMe radicals and three hexafluoroacetylacetonate ligands. The luminescent explorations show that complex 1 with high sensitivity, selectivity, almost linear at low concentration and the low detection limit for detection of Cr3+ (1 μM) and Cr2O72− (0.1 μM) ions in aqueous solutions.