Syntheses, Reactivity, X-ray Structures, and Antioxidant Properties of Ruthenium(II) Complexes with Aryl/Ferrocenyl-Fluorodithiophosphate Ligands [PPh 4 ][(X)FPS 2 ] (X = p -Methoxy-C 6 H 4 , p -Ethoxy-C 6 H 4 , Ferrocenyl)

Reaction of Lawesson’s reagent analogue precursors with dry potassium fluoride as the fluorinating agent in the presence of tetraphenylphosphonium bromide gave three aryl/ferrocenyl-fluorodithiophosphate ligands [PPh 4 ][( p -methoxy-C 6 H 4 )FPS 2 ] ( L1 ), [PPh 4 ][( p -ethoxy-C 6 H 4 )FPS 2 ] ( L2 ), and [PPh 4 ][( Fc )FPS 2 ] ( L3 ) ( Fc = Fe(η 5 -C 5 H 4 )(η 5 -C 5 H 5 )). The treatment of [(η 6 - p -cymene)RuCl 2 ] 2 (η 6 - p -cymene = 1-methyl-4- iso -propyl-benzene) with equivalent L1 and L3 in dichloromethane afforded a binuclear ruthenium(II) complex [(η 6 - p -cymene)Ru{κ 2 - S,μ- S′ -( p -methoxy-C 6 H 4 )FPS 2 }] 2 ( 1 ) and a mononuclear ruthenium(II) complex [(η 6 - p -cymene)ClRu{κ 2 - S, S′ -( Fc )FPS 2 }] ( 2 ), respectively. Interaction of cis -[(phen) 2 RuCl 2 ] (phen = o -phenanthroline) with L1 and L2 in methanol at reflux gave mononuclear ruthenium(II) complexes trans -[(phen) 2 Ru{(κ 1 - S -( p -methoxy-C 6 H 4 )FPS 2 )} 2 ] ( 3 ) and trans -[(phen) 2 Ru{(κ 1 - S -( p -ethoxy-C 6 H 4 )FPS 2 )} 2 ] ( 4 ), respectively. Precursors pre- L1 –pre- L3, ligands L1 – L3, and ruthenium(II) complexes 1 – 4 were well-characterized by IR, NMR, UV–vis, and TOF-MS spectroscopies. The structures of precursor pre- L3, ligands L1 and L3, and ruthenium(II) complexes 1 – 4 have been established by single-crystal X-ray crystallography. Moreover, the antioxidant properties of ruthenium(II) complexes 1 – 4 were evaluated using DPPH free radical and ABTS cation radical-scavenging activities in vitro.