Unsaturated ether chelate complexes of ruthenium(II)

Abstract

The complexes [Ru{η⁵-C₅Me₄CH₂O(CH₂)_nCHCR¹R²}(CO)₂Cl](2a R¹= R²= H, n= 1; 2b R¹= R²= H, n= 2; 2c R¹= H, R²= Me, n= 1; 2d R¹= Me, R²= H, n= 1) were prepared by heating [Ru(η⁵-C₅Me₄CH₂Cl)(CO)₂Cl]1 with the appropriate unsaturated alcohol. Reaction of complexes 2 with AgBF₄ led to loss of the chloride ligand and the formation of the cationic chelate complexes [Ru{η⁵:η²-C₅Me₄CH₂O(CH₂)_nCHCR¹R²}(CO)₂]BF₄, with the double bond co-ordinated to the metal centre. Single-crystal X-ray structures determined for the complexes [Ru{η⁵:η²-C₅Me₄CH₂OCH₂CHCH₂}(CO)₂]BPh₄ and [Ru{η⁵:η²-C₅Me₄CH₂O(CH₂)₂CHCH₂}(CO)₂]BF₄ confirmed that the double bond was co-ordinated to the metal. The neutral chelate complex [Ru{η⁵:η²-C₅Me₄CH₂OCH₂CHCH₂}(CO)Cl] was formed on addition of trimethylamine N-oxide to a solution of 2a by the replacement of one of the carbonyl ligands with the alkene on the pendant arm.