Oximated ruthenium tris-bipyridyl complex: synthesis and luminescent response specifically for ClO− in water containing multiple ions

Abstract

Hypochlorite has been widely and essentially used as the disinfecting agent of water in our daily life. Rapidly, specifically, quantitatively and simply monitoring ClO⁻ in water remains to be investigated and is of importance. For this purpose a novel complex bis(2,2′-bipyridine)(4′-methyl-2,2′-bipyridyl-4-carbaldehyde oxime)ruthenium chloride (Ru–CN–OH) was prepared. In water, reaction of complex Ru–CN–OH and ClO⁻ results in bis(2,2′-bipyridine)(4′-methyl-2,2′-bipyridyl-4-carboxylic acid)ruthenium (Ru–CO₂H) and thereby offers an efficient luminescence response. This was ascertained to be a specific oxidation reaction of complex Ru–CN–OH with ClO⁻, and can be used for quantitatively monitoring aqueous ClO⁻. The product of the oxidation reaction of complex Ru–CN–OH and ClO⁻ was isolated and assigned to Ru–CO₂H. The luminescent emission spectra of complex Ru–CN–OH in the presence of ClO⁻ demonstrated that the coexistence of F⁻, Cl⁻, Br⁻, I⁻, HCO₃⁻, HSO₄⁻, H₂PO₄⁻, S₂O₃²⁻, SO₃²⁻, CO₃²⁻, PO₄³⁻, HPO₄²⁻, NO₃⁻, AcO⁻, Li⁺, Na⁺, K⁺, Ca²⁺, Mg²⁺, Zn²⁺, Co²⁺, Fe³⁺, Ni²⁺, Pb²⁺, Hg²⁺, Mn²⁺ and Cu²⁺ did not interfere in the quantitative change of the intensity of the luminescent emission.