Synthesis, characterization, reactivity and structure of some mono and binuclear (η⁶-p-cymene)ruthenium(II) complexes

Abstract

Reactions of [{Ru(η⁶-C₁₀H₁₄)Cl₂}₂] (η⁶-C₁₀H₁₄=p-cymene H₃CC₆H₄CH(CH₃)₂) with 4-cyanopyridine (referred hereafler as CNPy) in 1:1 and 1:2 molar ratios in dichloromethane yields the binuclear complex [{Ru(η⁶-C₁₀H₁₄)Cl₂}₂(μ-CNPy)] and the mononuclear complex [Ru(η⁶-C₁₀H₁₄)Cl₂(CNPy)]. The latter complex further reacts with [{Ru(η⁶-C₆Me₆)Cl₂}₂] and [Ru(η⁵-C₅H₅)(PPh₃)₂Cl] to give 4-cyanopyridine bridged complexes [Cl₂(η⁶-C₁₀H₁₄)Ru(μ-CNPy)Ru(μ⁶-C₆Me₆)Cl₂] and [Cl₂(η⁶-C₁₀H₁₄)Ru(μ-CNPy)Ru(η⁵-C₅H₅)(PPh₃)₂]⁺. The complex [Ru(η⁶-C₁₀H₁₄)Cl₂(CNPy)] also undergoes metathetical reactions with EPh₃ (E=P, As or Sb) to give complexes with the general formulations [Ru(η⁶-C₁₀H₁₄)Cl₂(EPh₃)], however its reaction with diphenylphosphinomethane (dppm) in a 1:1 ratio gives the mononuclear complex [Ru(η⁶-C₁₀H₁₄)Cl₂(dppm)] in which the dppm ligand is present in uncommon coordination mode (η¹-dppm). The reaction products have been characterized by microanalyses and spectroscopic studies (IR, ¹H-, ¹³C-, ³¹P-NMR). The structure of [Ru(η⁶-C₁₀H₁₄)Cl₂(CNPy)] [a=10.984(1), b=14.052(1), c=12.189(1) Å; β=114.810(1)°; V=1707.8(4) ų; D_calc=1.596 gcm⁻³; monoclinic P2₁/c; Z=4] and confirmation of uncommon coordination mode of dppm, in [Ru(η⁶-C₁₀H₁₄)Cl₂(dppm)] [a=11.504(3), b=19.532(3), c=15.942(3) Å; β=96.08(2)°; V=3562(2) ų; D_calc=1.446 gcm⁻³; monoclinic P2₁/n; Z=4] has been determined by X-ray crystallography.