Synthesis, characterisation and reactions of ruthenium(II) complexes based upon [RuL3]2+ (L3 = tripodal triseleno- or tritelluro-ether) fragments. Structures of [RuCl2(PPh3){MeC(CH2SeMe)3}] and [RuCl2(dmso){MeC(CH2SeMe)3}]

Abstract

The reaction of [RuCl₂(PPh₃)₃] with tripodal Group 16 donor ligands L³ {MeC(CH₂EMe)₃ (E = Se or Te) and MeC(CH₂TePh)₃} gave [RuCl₂(PPh₃)L³] complexes which have been characterised by elemental analysis, IR and NMR spectroscopy and ES⁺ mass spectrometry. The structure of [RuCl₂(PPh₃){MeC(CH₂SeMe)₃}] reveals a distorted octahedral geometry with a facially co-ordinated triselenoether. The reaction of [RuCl₂(dmso)₄] with L³ gave [RuCl₂(dmso)L³] which have similarly been characterised, including a crystal structure of [RuCl₂(dmso){MeC(CH₂SeMe)₃}], which is fac-octahedral with S-bonded dmso. The [RuCl₂(dmso)L³] species react with Ag[CF₃SO₃] in MeCN to produce [Ru(MeCN)₃L³]²⁺ {L³ = MeC(CH₂SeMe)₃ or MeC(CH₂TePh)₃}. The MeCN is labile and readily replaced by a second tridentate ligand to give mixed tripod ligand complexes including [Ru{MeC(CH₂SMe)₃}{MeC(CH₂SeMe)₃}][CF₃SO₃]₂ and [Ru{MeC(CH₂SeMe)₃}{MeC(CH₂TePh)₃}][CF₃SO₃]₂. Attempts to generate hydride species by reaction of [Ru(MeCN)₃L³]²⁺ with NaBH₄ in ethanol bring about decomposition.

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