Quinolone Complexes with Lanthanide Ions: An Insight into their Analytical Applications and Biological Activity

. 2020 Mar 16;25(6):1347. doi: 10.3390/molecules25061347

a.	FQ-Tb³⁺-Ce⁴⁺-SO₃⁻-H₂SO₄ system:
	Ce⁴⁺ + HSO₃^- → Ce³⁺ + HSO₃^* 2HSO₃^* → S₂O₆^2- + 2H⁺ S₂O₆²⁻ → SO₄^2- + SO₂^*	SO₂^* + Ln(FQ)₂³⁺ → SO₂ + Ln(FQ^)₂³⁺ Ln(FQ^)₂³⁺ → Ln^(FQ)₂³⁺ Ln^(FQ)₂³⁺ → Ln(FQ)₂³⁺ + hν, FQ = levofloxacin, moxifloxacin, trovafloxacin [110];
b.	FQ-Ce⁴⁺-S₂O₄²⁻-HNO₃ system:
	S₂O₃²⁻/S₂O₄²⁻ + H⁺ → HSO₃⁻ + H₂O Ce⁴⁺ + HSO₃⁻ → HSO₃^∗ + Ce³⁺ 2HSO₃^∗ → S₂O₆²⁻ + 2H⁺ S₂O₆²⁻ → SO₄²⁻ + SO₂^∗	SO₂^∗ → SO₂ + hν Ce⁴⁺ +FQ + H⁺ → Ce³⁺ + FQ oxide + H₂O SO₂^∗ +FQ oxide → FQ oxide^∗ + SO₂ FQ oxide^∗ → FQ oxide + hν, FQ = norfloxacin [109];
c.	Ln⁺³-FQ-Ce⁴⁺-S₂O₄²⁻ system:
	S₂O₄²⁻/S₂O₃²⁻ + H⁺→ HSO₃⁻ Ce⁴⁺ + HSO₃⁻→ HSO₃^∗ + Ce³⁺ 2HSO₃^∗ → S₂O₆²⁻ + 2H⁺ S₂O₆²⁻ → SO₄²⁻ + SO₂^∗	SO₂^* + [Ln–FQ]³⁺→SO₂ + [Ln–FQ^*]³⁺ [Ln–FQ^∗]³⁺→ [Ln^∗–FQ]³⁺ [Ln^∗–FQ]³⁺→ [Ln–FQ]³⁺+hν, FQ = gatifloxacin, enoxacin, Ln = Eu³⁺, Dy³⁺ [109].