Reaction of the dimers [RuCl 2 (arene)] 2 (arene ) benzene, p-cymene, mesitylene) with bis-(oxazolines) (N-N ) bis(2-oxazoline) (box), 2,2-bis(2-oxazolinyl)propane (bop), 1,2-bis(2oxazolinyl)benzene (benbox)) in the presence of NaSbF 6 gives the complexes [RuCl(N-N)(arene)][SbF 6 ] (1-8), which have been fully characterized. Treatment of these cations with AgSbF 6 generates dications which in some cases are enantioselective catalysts for Diels-Alder reaction of methacrolein and cyclopentadiene. Two complexes, [RuCl( i Pr-benbox)(pcymene)][SbF 6 ] ( 5) and [Ru(OH 2 )( i Pr-bop)(mes)][SbF 6 ] 2 (10; mes ) mesitylene), have been characterized by X-ray crystallography.