Preparation and characterization of rhodium(iii), iridium(iii) and ruthenium(ii) bearing 1,3- or 1,4-dithianes

Abstract

Reactions of [Cp*MCl₂]₂ (1a: M = Rh, 1b: M = Ir) or [(arene)RuCl₂]₂ (1c: arene = p-cymene; 1d: arene = C₆Me₆) with 1,3-dithiane (1,3-S₂C₄H₈) gave [{LMCl₂}₂(1,3-S₂C₄H₈)] 2 and [(LMCl₂)( 1,3-S₂C₄H₈)] 3 (LM = Cp*Rh, Cp*Ir, or (p-cymene)Ru, (C₆Me₆)Ru), depending on molar ratios between 1 and 1,3-dithiane. The reaction in the presence of KPF₆ afforded the corresponding ionic complexes [LMCl(1,3-S₂C₄H₈)₂](PF₆) 4. Complex 3a was treated with 1b, affording the heterobinuclear complex [Cp*RhCl₂(1,3-S₂C₄H₈)IrCl₂Cp*] 2ab. Complex 2ab was obtained by a similar reaction of 3b with 1a, whereas reactions of 1c with 3a or 3b gave homonuclear complexes 2c and 2a (or 2b). Ionic complexes 4 were treated with 1, generating homo- or hetero-trinuclear complexes [{LMCl(1,3-S₂C₄H₈)₂}(L′MCl₂)₂](PF₆) 5 (LM = Cp*Ir, L′M = Cp*Rh, Cp*Ir, or (p-cymene)Ru: LM = Cp*Rh, L′M = (p-cymene)Ru). Reactions of 1 with 1,4-dithiane (1,4-S₂C₄H₈) were carried out in a 1 ∶ 1 molar ratio, generating binuclear complexes [(Cp*MCl₂)₂(1,4-S₂C₄H₈)] (6a: M = Rh; 6b: M = Ir) or [{(arene)RuCl₂}₂(1,4-S₂C₄H₈)] (arene = p-cymene (6c), C₆Me₆ (6d)). Reaction of 1a with an excess of 1,4-dithiane afforded a neutral mononuclear complex [Cp*RhCl₂(1,4-S₂C₄H₈)] 7a, whereas the reactions of 1b or 1c generated the corresponding ionic complexes [Cp*IrCl(1,4-S₂C₄H₈)](Cl) 8b and [(p-cymene)RuCl(1,4-S₂C₄H₈)](Cl) 8c. Treatment in the presence of KPF₆ gave ionic complexes [LM(1,4-S₂C₄H₈)](PF₆) (LM = Cp*Rh (9a), Cp*Ir (9b), (p-cymene)Ru (9c)) Structures of 2a, 2ab, 3a, 3c, 4a, 8b and 9c were confirmed by X-ray analyses.