Synthesis And Reactivity Of Ruthenium(Ⅳ)Complexes With Arylthiolate Ligands

Synthesis, structure and reactivity of ruthenium(IV) complexes with arylthiolateligands were reported in this thesis. The reaction of [Et4N][RuCl5(MeCN)] with5equivalents of NaSMes (derived from the reaction of Mes2S2with NaBH4inTHF-MeOH) in MeOH-MeCN (2:1) isolated ruthenium(IV) complexes[Ru(SMes)4(MeCN)](1a) and [Et4N][Ru(SMes)4Cl](1b) through columnchromatography on silica gel technology, whose isolated yield was79.7%and5.1%,respectively. Structural determination through single crystal X-ray diffraction revealedthat the geometry around Ru of complexes1a and1b were trigonal bipyramidal, thethree arylthiolates of the planar trigonal [Ru(SMes)3]+cores adopted a “two-upone-down” conformation, the average Ru－Seqbond lengths were2.209and2.202, Ru－Saxwere2.3917(7) and2.4132(14), which were obviously longer thanRu－Seqbond lengths.Substitution reaction of the axial ligands and the cyclometallated reaction of thecentral Ru atom was explored on the stable complex1a. Protonation of complex1awith HCl in THF afforded ruthenium(IV) complex [Ru(SMes)3(MeCN)Cl](2a). Thereaction of complex1a with equal equivalent of3,5-Lutidine,4-ethylpyridine or4-tert-butylpyridine formed the corresponding substituted complexes[Ru(SMes)4(3,5-Me2-py)](3a),[Ru(SMes)4(4-Et-py)](3b) and [Ru(SMes)4(4-But-py)](3c), respectively; While treatment of complex1a with0.5equivalent of4,4′-bipyridine gave dinuclear ruthenium(IV) complex [{Ru(SMes)4}2(4,4′-bpy)](3d),the axial MeCN ligand of complex1a was substituted by pyridyl ligands in thereaction process. Moreover, treatment of complex1a with excess alkynols2-methyl-3-butyn-2-ol,3-ethyl-1-pentyn-3-ol or1-ethynyl-1-cyclohexanol led toisolation of structural novel dinuclear vinyl cyclometallated ruthenium(IV) complexes[(μ-SMes)Ru{η1-O,η1-C-OCMe2CH=C(SMes)}(SMes)]2(4a),[(μ-SMes)Ru{η1-O,η1-C-OCMe2CH=C(SMes)}(SMes)]2(4b) and[(μ-SMes)Ru{η1-O,η1-C-OC(1,5-pentylene)CH=C(SMes)}(SMes)]2(4c), respectively.Substitution reaction of the axial thiolate ligands, elimination reaction of HSMesmolecule, cis-addition of HSMes molecule to ethynyl, the cyclometallated reactionand dimerization reaction of formation of dinuclear vinyl cyclometallatedruthenium(IV) complexes may be involved in the course of formation of complexes4a,4b and4c.Complexes2a,3a,3b,3c,3d,4a,4b and4c were characterized by IR, NMR, MS and Elemental Analysis, and their structures were established by single crystalX-ray diffraction. The coordination geometries around Ru atom were all trigonalbipyramidal, similar to complexes1a and1b, the three arylthiolates of the planartrigonal [Ru(SMes)3]+cores of complexes2a,3a,3b,3c and3d adopted a “two-upone-down” conformation, whose Ru－N bond lengths were2.006(5),2.171(5),2.179(3),2.208(3) and2.182(7), respectively; In complexes4a,4b and4c, the{OCR2CH=C(Smes)} species chelate the ruthenium centers with almost co-planarfive-numbered metallacycles linked by a butterfly structural Ru2S2unit, accordingRu－C bond lengths were2.011(3),2.023(5) and2.04(2), Ru－O bond lengthswere1.8641(18),1.883(3) and1.718(17), and Ru－Saxbond lengths were2.6165(7),2.6364(14) and2.624(5), which were obviously longer than Ru－Saxbond length ofcomplex1a (2.3917(7)).