Synthese,Charakterisierung und Struktur von Carbonylund Hydrido-Isocyanatokomplexen des Rutheniums

Synthesis, Characterization, and Structure of Carbonyl and Hydrido Isocyanato Complexes of Ruthenium [Ru(CO)H(NCO)(PPh₂Me)₃] is formed during the reaction between [RuCl₃(PPh₂Me)₃] and NaOCN in EtOH. The compound crystallizes in the monoclinic space group P2₁/n (a = 1256.4(4), b = 1487.2(2), c = 1993.5(5) pm, β = 97.28(1)°, Z = 4). The distorted octahedral coordination sphere of Ru^II contains the phosphine ligands in meridional arrangement, their P atoms forming a plane together with the hydride ligand. The reaction of [RuCl₃(PPh₃)₂] with NaOCN in EtOH yields [Ru(NCO)(CO)(CH₃COO)(PPh₃)₂] with trans coordinated Ph₃P ligands. The formation of hydrido, carbonyl and acetato ligands are due to the reaction of the transition metal with the solvent ethanol.     

Chemistry of a family of semiquinone monochelates of carbonyl ruthenium(II) generated by reacting quinones with hydridic species

The reactions of [Ru(H)(Cl)(CO)(PPh₃)₃] with 3,5-di-tert-butyl-o-benzoquinone (dbq) and 3,4,5,6-tetrachloro-o-benzoquinone (tcq) have afforded the corresponding semiquinone complexes [Ru^II(dbsq)(Cl)(CO)(PPh₃)₂] and [Ru^II(tcsq)(Cl)(CO)(PPh₃)₂], respectively. The reaction of [Ru(H)₂(CO)(PPh₃)₃] with tcq has furnished [Ru^II(tcsq)(H)(CO)(PPh₃)₂]. Structure determination of [Ru(dbsq)(Cl)(CO)(PPh₃)₂] has revealed that it is a model semiquinonoid chelate with two equal C---O lengths ( 1.291(6) and 1.296(6) Å). The complexes are one-electron paramagnetic (1.85μ_B) and their EPR spectra in fluid media display a triplet structure (g2.00) due to superhyperfine coupling with two trans-³¹P atoms (A_iso17 G). The stretching frequency of the CO ligand increases by 20 cm⁻¹ in going from [Ru(dbsq)(Cl)(CO)(PPh₃)₂] to [Ru(tcsq)(Cl)(CO)(PPh₃)₂] consistent with electron withdrawal by chloro substituents. For the same reason the E_1/2 values of the cyclic voltammetric quinone/semiquinone and semiquinone/catechol couples undergo a shift of 500 mV to higher potentials between [Ru(dbsq)(Cl)(CO)(PPh₃)₂] and [Ru(tcsq)(Cl)(CO)(PPh₃)₂].     

A SIMPLE ROUTE FOR SYNTHESES OF TRIHALIDE-BRIDGED CARBONYL DIRUTHENIUM(II,III) COMPLEXES: CRYSTAL AND MOLECULAR STRUCTURE OF ttt-[RuIICl2(CO)2(PPh3)2],[(CO)(AsPh3)2RuII(μ-Cl3)RuIIICl2(AsPh3)] AND ([CO)(PPh3)2RuII(μ-Br3)RuIIIBr2(PPh3)], SPECTROSCOPIES,ELECTROCHEMISTRY AND PROPERTIES

Abstract

The triply halide-bridged binuclear complexes [Ru₂Cl₅(CO)(AsPh₃)₃] (AsPh₃ = triphenylarsine), [Ru₂Cl₅(CO)(PPh₃)₂(AsPh₃)] (PPh₃ = triphenylphosphine), [Ru₂Cl₅(CO)(AsPh₃)₂(PPh₃)], [Ru₂ Br₅(CO)(PPh₃)₃], [Ru₂Cl₅(CO)(P{p-tol}₃)₂(PPh₃)] (P{p-tol}₃ = tri-p-tolylphosphine) and [Ru₂ Br₂Cl₃(PPh₃)₂(AsPh₃)] were prepared from the precursor compounds ttt-[RuX₂(CO)₂(P)₂] (X = Cl or Br) and [RuY₃(P')₂S]·S (Y = Cl or Br; P=PPh₃, AsPh₃ or P{p- tol}₃ and P' = AsPh₃ or PPh₃; S=DMA or MeOH, where DMA = N,N'-dimethylacetamide). The molecular structures of the binuclear complexes [Ru₂Cl₅(CO)(AsPh₃)₃] (P2_1/c), [Ru₂Br₅(CO)(PPh₃)₃] (P2_1/c) and ttt-[RuCl₂(CO)₂(PPh₃)₂] (P1) were determined by X-ray diffraction methods. The complexes are always formed by two Ru atoms bridged through three halide anions, two of which are × type (from the Ru^II precursor) and the other is Y type (from the ruthenium^III precursor) confirming our previously suggested mechanism for obtaining this class of complexes. The Ru^II atom is also coordinated to a carbon monoxide molecule and two P ligands from the ttt-starting isomer whereas the Ru^III atom is bonded to two non-bridging Y halides and one P' molecule. The presence of Ru^III was confirmed by EPR data, a technique that was also useful to suggest the symmetry of the complexes. The absence of intervalence charge-transfer transitions (IT) in the near infrared spectrum confirms that the binuclear complexes have localized valence. The IR spectra of the complexes show; (CO) bands close to 1970 cm^?1 and ν(Ru-Cl) or(Ru-Br) bands at about 230–380 cm^?1 corresponding to halides at terminal or bridged positions. Two widely separated redox processes, Ru^II/Ru^II←Ru^II/Ru^III→Ru^III/Ru^III, were observed by cyclic voltammetry and differential pulse voltammetry.     

Chemistry of ruthenium in N2P2X2 (X = Cl, Br) coordination sphere: Synthesis, characterization and reactivities

Reaction of 2-(phenylazo)pyridine (pap) with [Ru(PPh₃)₃X₂] (X = Cl, Br) in dichloromethane solution affords [Ru(PPh₃)₂(pap)X₂]. These diamagnetic complexes exhibit a weakdd transition and two intense MLCT transitions in the visible region. In dichloromethane solution they display a one-electron reduction of pap near − 0.90 V vs SCE and a reversible ruthenium(II)-ruthenium(III) oxidation near 0.70 V vs SCE. The [Ru^III(PPh₃)₂(pap)Cl₂]⁺ complex cation, generated by coulometric oxidation of [Ru(PPh₃)₂(pap)Cl₂], shows two intense LMCT transitions in the visible region. It oxidizes N,N-dimethylaniline and [Ru^II(bpy)₂Cl₂] (bpy = 2,2′-bipyridine) to produce N,N,N′,N′-tetramethylbenzidine and [Ru^III(bpy)₂Cl₂]⁺ respectively. Reaction of [Ru(PPh₃)₂(pap)X₂] with Ag⁺ in ethanol produces [Ru(PPh₃)₂(pap)(EtOH)₂]²⁺ which upon further reaction with L (L = pap, bpy, acetylacetonate ion(acac⁻) and oxalate ion (ox²⁻)) gives complexes of type [Ru(PPh₃)₂(pap)(L)]ⁿ⁺ (n = 0, 1, 2). All these diamagnetic complexes show a weakdd transition and several intense MLCT transitions in the visible region. The ruthenium(II)-ruthenium(III) oxidation potential decreases in the order (of L): pap > bpy > acac⁻ > ox²⁻. Reductions of the coordinated pap and bpy are also observed.     

Synthesis and spectroscopic studies of some new metal carbonyl derivatives of 1-(2-pyridylazo)-2-naphthol

Interaction of 1-(2-pyridylazo)-2-naphthol (PAN) with [Mo(CO)₆] in air resulted in formation of the tricarbonyl oxo-complex [Mo(O)(CO)₃(PAN)], 1. The dicarbonyl complex [Ru(CO)₂(PAN)], 3, was obtained from the reaction of [Ru₃(CO)₁₂] with PAN. In presence of triphenyl phosphine (PPh₃), the reaction of PAN with either Mo(CO)₆ or Ru₃(CO)₁₂ gave [Mo(CO)₃(PAN)(PPh₃)], 2, and [Ru(CO)₂(PAN)(PPh₃)], 4. All the complexes were characterized by elemental analysis, mass spectrometry, IR, and NMR spectroscopy. The thermal properties of the complexes were also investigated by thermogravimetry.     

Synthesis,Characterization, and X‐ray Structures of Ru3(CO)9(dotpm)(L) Complexes [L = PPh3, P(C6H4Cl‐p)3, and PPh2(C6H4Br‐p)]

The reaction of Ru₃(CO)₁₀(dotpm) ( 1 ) [dotpm = (bis(di‐ortho‐tolylphosphanyl)methane)] and one equivalent of L [L = PPh₃, P(C₆H₄Cl‐p)₃ and PPh₂(C₆H₄Br‐p)] in refluxing n‐hexane afforded a series of derivatives [Ru₃(CO)₉(dotpm)L] ( 2 – 4 ), respectively, in ca. 67–70 % yield. Complexes 2 – 4 were characterized by elemental analysis (CHN), IR, ¹H NMR, ¹³C{¹H} NMR and ³¹P{¹H} NMR spectroscopy. The molecular structures of 2 , 3 , and 4 were established by single‐crystal X‐ray diffraction. The bidentate dotpm and monodentate phosphine ligands occupy equatorial positions with respect to the Ru triangle. The effect of substitution resulted in significant differences in the Ru–Ru and Ru–P bond lengths.     

Diphenylphosphine and diphenylphosphido derivatives of [Ru3(μ-H)(μ3-ampy)(CO)9] (Hampy = 2-amino-6-methylpyridine)

The reactions of [Ru₃(μ-H)(μ-ampy)(CO)₉] (1) (Hampy = 2-amino-6-methylpyridine) with one or two equivalents of PPh₂H lead to the complexes [Ru₃(μ-H)(μ₃-ampy)(CO)₈(PPh₂H)] (2) or [Ru₃(μ-H)(μ₃-ampy)(CO)₇(PPh₂H)₂] (3), in which the PPh₂H ligands are cis to the bridging NH fragment and cis to the hydride. Complex 2 can be transformed in refluxing THF into the phosphido-bridged derivative [Ru₃(μ₃-ampy)(μ-PPh₂)(μ-CO)₂(CO)₆] (4), which contains the PPh₂ ligand spanning one of the two RuRu edges unbridged by the amido moiety, and presents an extremely high ³¹P chemical shift of 386.9 ppm. Under similar conditions, complex 3 gives a mixture of two isomers of [Ru₃(μ-H)(μ₃-ampy)(μ-PPh₂)₂(CO)₆] in a 5:1 ratio; the major product (5) has a plane of symmetry, whereas the minor one (6) is asymmetric.     

Ruthenium(II) complexes of aroylhydrazones: structural,electrochemical and electrostatic interactions with DNA

Four Ru(II) complexes with tridentate ligands viz. (4-hydroxy-N′-(pyridin-2-yl-ethylene) benzohydrazide [Ru(L¹)(PPh₃)₂(Cl)] (1), N′-(pyridin-2-yl-methylene) nicotinohydrazide [Ru(L²)(PPh₃)₂(Cl)] (2), N′-(1H-imidazol-2-yl-methylene)-4-hydroxybenzohydrazide [Ru(L³)(PPh₃)₂(Cl)] (3), and N′-(1H-imidazol-2-yl-methylene) nicotinohydrazide [Ru(L⁴)(PPh₃)₂(Cl)] (4) have been synthesized and characterized. The methoxy-derivative of L³H (abbreviated as L³H*) exists in E configuration with torsional angle of 179.4° around C₇-N₈-N₉-C₁₀ linkage. Single crystal structures of acetonitrile coordinated ruthenium complexes of 1 and 3 having compositins as [Ru(L¹)(PPh₃)₂(CH₃CN)]Cl (1a) and [Ru(L³)(PPh₃)₂(CH₃CN)]Cl (3a) revealed coordination of tridentate ligands with significantly distorted octahedral geometry constructed by imine nitrogen, heterocyclic nitrogen, and enolate amide oxygen, forming a cis-planar ring with trans-placement of two PPh₃ groups and a coordinated acetonitrile. Ligands (L¹H-L⁴H) and their ruthenium complexes (1–4) are characterized by ¹H, ¹³C, ³¹P NMR, and IR spectral analysis. Ru(II) complexes have reversible to quasi-reversible redox behavior having Ru(II)/Ru(III) oxidation potentials in the range of 0.40–0.71 V. The DNA binding constants determined by absorption spectral titrations with Herring Sperm DNA (HS-DNA) reveal that L⁴H and 1 interact more strongly than other ligands and Ru(II) complexes. Complexes 1–3 exhibit DNA cleaving activity possibly due to strong electrostatic interactions while 4 displays intercalation.     

Syntheses,structures and electrochemical properties of ruthenium(II/III) complexes with tetradentate Schiff base ligands

Three unsymmetrical tetradentate Schiff base ligands, H₂salipn, H₂salipn-Br₄ and H₂salipn-Cl₂, have been synthesized from the typical condensation reactions of treating 1,2-diaminopropane with salicylaldehyde, 3,5-dibromosalicylaldehyde and 5-chlorosalicylaldehyde, respectively. Treatment of [RuCl₂(PPh₃)₃] with one equivalent of H₂salipn or H₂salipn-Br₄ in the presence of triethylamine in tetrahydrofuran (THF) afforded the corresponding ruthenium(III) complexes [Ru^IIICl(PPh₃)(salipn)] (1) and [Ru^IIICl(PPh₃)(salipn-Br₄)] (2). Interaction of [RuHCl(CO)(PPh₃)₃] with one equivalent of H₂salipn-Cl₂ or H₂salipn-Br₄ under the same conditions led to isolation of ruthenium(II) complexes [Ru^II(CO)(PPh₃)(salalipn-Cl₂)] (3) and [Ru^II(CO)(PPh₃)(salalipn-Br₄)] (4), respectively, in which one of the imine bonds was nucleophilically attacked by hydride to result in the formation of a mixed imine-amine ligand. The molecular structures of 1?1.5CH₂Cl₂, 2, 3?0.5CH₂Cl₂ and 4 have been determined by single-crystal X-ray crystallography. The electrochemical properties of 1–4 were also investigated. Their cyclic voltammograms displayed quasi-reversible Ru(IV)/Ru(III) and Ru(III)/Ru(II) couples with E^o ranging from 0.67 to 1.05 V and 0.74 to 0.80 V vs. Ag/AgCl (0.1 M), respectively.     

Novel bidentate ruthenium(III) Schiff base complexes: synthetic,spectral, electrochemical,catalytic and antimicrobial studies

Ru^III complexes of the type [RuX(L)₂(E)] (X = Cl or Br; L = novel bidentate Schiff base ligand; E = PPh₃ or AsPh₃) have been prepared by reacting [RuX₃(E)₃] or [RuBr₃(PPh₃)₂(MeOH)] with two novel bidentate Schiff base ligands derived from 4-(1-methyl-1-mesitylcyclobutane-3-yl)-2-aminothiazole, in a 1:2 molar ratio in benzene, and characterised by analytical, spectral (i.r., electronic, ¹H-, ¹³C- n.m.r., and e.p.r.) and electrochemical data. An octahedral structure has been tentatively proposed for all the new complexes. The thermal properties of the ligands and their complexes have been studied by t.g.a. The new Ru^III complexes are effective catalysts for the oxidation of alcohols to carbonyl compounds but are unable to oxidise alkenes in the presence of N-methylmorpholine-N-oxide (NMO) as co-oxidant. The antimicrobial activity of the ligands and complexes have also been tested against six microorganisms.     

A TRICHLORO-BRIDGED DIRUTHENIUM (II,III) COMPLEX: PREPARATION,PROPERTIES AND X-RAY STRUCTURE OF TRI(-μ-CHLORO) DICHLOROCARBONYLTRIS (TRIPHENYLPHOSPHINE)DIRUTHENIUM(II,III)

Abstract

The triply chloro-bridged binuclear complex [Ru₂Cl₅(CO)(PPh₃)₃]·CH₂Cl₂, (PPh₃ = triphenylphosphine), M_r = 1279.23, prepared from the precursor compound [RuCl₃(PPh₃)₂DMA]·DMA (DMA = N,N′-dimethylacetamide) and crystallizes in the monoclinic space group P2₁/c. The structure was solved from 6994 independent reflections for which I > 3σ(I) by Patterson and difference Fourier techniques and refined to a final R = 0.042. The complex is formed by two Ru atoms bridged through three chloride anions. One Ru atom is further coordinated to two non-bridging Cl atoms and a triphenylphosphine ligand, whereas the other is bonded to two PPh₃ ligands and a carbon monoxide molecule. The presence of Ru^III was confirmed by EPR data. The absence of an intervalence charge-transfer transition (IT) in the near-infrared spectrum suggests that the binuclear complex is of a localized valence type. The IR spectrum shows a ν_CO band at 1964cm^? and ν_Ru-Cl bands at 328, 280 cm^?1, corresponding to chlorides at terminal positions and 250, 225 cm^?1 for the bridged ones. Two redox processes, Ru^II/Ru^II (E_1/2 = -0.29 V) ← Ru^II/Ru^III ← (E_1/2 = 1.19 V) Ru^III/Ru^III, were observed by cyclic voltammetry.     

Ruthenium(III) mediated C-H activation of azonaphthol: Synthesis, structural characterization and transfer hydrogenation of ketones

Treatment of [RuCl₃(PPh₃)₃] with 1-(arylazo)naphthol ligands in benzene under reflux afford air-stable new organoruthenium(III) complexes with general composition [Ru(an-R)Cl(PPh₃)₂] (where, R = H, Cl, CH₃, OCH₃, OC₂H₅) in fairly good yield. The 1-(arylazo)naphtholate ligands behave as dianionic tridentate C, N, O donors and coordinates to ruthenium through phenolic oxygen, azo nitrogen and ortho carbon generate two five-membered chelate rings. The composition of the complexes have been established by analytical (elemental analysis and magnetic susceptibility measurement) and spectral (FT-IR, UV-Vis, EPR) methods. The complexes are paramagnetic (low-spin, d⁵) in nature and in dichloromethane solution show intense d-d transitions and ligand-to-metal charge transfer (LMCT) transitions in the visible region. The solution EPR spectrum of complex [Ru(an-CH₃)Cl(PPh₃)₂] (3) in dichloromethane at 77 K shows rhombic distortion around the ruthenium ion with three different ‘g’ values (g_x ≠ g_y ≠ g_z). The single crystal structure of the complex [Ru(an-OCH₃)Cl(PPh₃)₂] (4) has been characterised by X-ray crystallography, indicates the presence of a distorted octahedral geometry in these complexes. All the complexes exhibit one quasi-reversible oxidative response in the range 0.60-0.79 V (Ru^IV/Ru^III) and two quasi-reversible reductive responses (Ru^III/Ru^II; Ru^II/Ru^I) within the range −0.50 to −0.62 V and −0.93 to −0.98 V respectively. The formal potential of all the couples correlate linearly with the Hammett constant of the para substituent in arylazo fragment of the 1-(arylazo)naphtholate ligand. Further, the catalytic efficiency of one of the ruthenium complexes (4) was determined for the transfer hydrogenation of ketones with an excellent yield up to 99% in the presence of isopropanol/KOH.     

Synthesis, characterization and cyclic voltammetric studies of β-ketooximato ruthenium(II) complexes

Summary -Ketooxime [RC(O)C(NOH)R] (R = Me or Ph) ligands (HL) react with [Ru(PPh₃)₃Cl₂] in refluxing EtOH to yield [Ru(PPh₃)₂(L)₂] complexes. For R = Me, one isomer was obtained, while two isomers were isolated when R = Ph, due to a bulk effect. The complexes are diamagnetic and absorb intensely in the vis. region due to MLCT transitions. In MeCN and CH₂Cl₂ solution, Ru^II-Ru^III oxidation occurs in the 0.69–0.92 V versus s.c.e. range. The oxidation potential depends on both the electronic nature of R and the stereochemistry of the complexes.     

Synthesen und Kristallstrukturen neuer selenidoverbrückter Ruthenium-Clusterverbindungen

Syntheses and Crystal Structures of New Selenido-bridged Ruthenium Clusters The reaction of Se(SiMe₃)₂ with [RuCl₂(PPh₃)₃], or a mixture of [RuCl₂(PPh₃)₃] and alkylphosphines leads to the formation of selenido-bridged ruthenium clusters. In this publication the compounds [Ru₆Se₈(PPh₃)₆] ( 1 ), [Ru₆Se₈(PEt₃)₆] ( 2 ) und[Ru₆Se₈(PⁿPr₃)₆] ( 3 ) are described.The compounds 1-3 contain Ru₆¹⁶⁺ cluster cores with Ru²⁺ and Ru³⁺ centers. The structures of these compounds were elucidated by single crystal X-ray structural analyses.     

A dinuclear triple bonded RuRu compound: preparation and crystal structure of μ,μ′-1,2-phenylenediimine-(N,N′)-dicarbonylbis(triphenylphosphine)diruthenium(RuRu) (I)

Reaction of [Ru{1,2-C₆H₄(NH)₂}(PPh₃)₃] (1) with CO in toluene at room temperature afforsa as one of the products the dinuclear complex syn-[Ru₂{μ-1,2-C₆H₄(NH)₂}(CO)₂(PPh₃)₂] (2). The crystal structure of 2 reveals it to be an unsaturated bimetallic species, with two Ru(CO)(PPh₃) moieties bridged by an 8e⁻ donor η²-diimine ligand in a tetrahedral-like fashion and involving a triple RuRu bond.     

Spectral Properties of Ruthenium(II) Mixed-Ligands Complexes with 2,2'-Bipyridyl and Phosphines

Spectral-kinetic luminescence characteristics of the complexes cis-[Ru(bpy)(dppe)X2], cis- [Ru(bpy)2(PPh₃)X](BF₄) and cis-[Ru(bpy)₂X₂] [bpy = 2,2'-bipyridyl, dppe = 1,2-bis(diphenylphosphino)ethane, PPh₃ is triphenylphosphine, X = NO₂ ^- and CN^-] in the ethanol-methanol 4:1 mixtures and adsorbed on the oxide SiO₂ or porous polyacrylonitrile polymer surface were studied. Luminescence and luminescence exitation spectra were registered at 77 and 293 K in 230-750 nm range and the luminescence decay time was measured. Introduction of phosphine ligands to the ruthenium(II) bipyridyl complexes inner sphere leads to rise in singlet and triplet state energy at the charge transfer from Ru(II) to 2,2'-bipyridyl in the series [Ru(bpy)₂X₂] < Ru(bpy)₂(PPh₃)X](BF₄) < [Ru(bpy)(dppe)X₂]. The complex adsorption on SiO₂ or polyacrylonitrile surface affects noticeably the luminescence spectro-kinetic characteristics.     

Thiosemicarbazonates of Ruthenium(II): Crystal Structures of [Bis(triphenylphosphine)][bis(N‐phenyl‐pyridine‐2‐carbaldehyde Thiosemicarbazonato)]ruthenium(II) and [Bis(diphenylphosphino)butane][bis(salicylaldehyde Thiosemicarbazonato)]ruthenium(II)

Reaction of RuCl₂(PPh₃)₃ with N‐Phenyl‐pyridine‐2‐carbaldehyde thiosemicarbazone (C₅H₄N–C²(H)=N³‐N²H–C¹(=S)N¹HC₆H₅, Hpytsc‐NPh) in presence of Et₃N base led to loss of ‐N²H‐proton and yielded the complex [Ru(pytsc‐NPh)₂(Ph₃P)₂] ( 1 ). Similar reactions of precursor RuCl₂[(p‐tolyl)₃P]₃ with a series of thiosemicarbazone ligands, viz. pyridine‐2‐carbaldehyde thiosemicarbazone (Hpytsc), salicylaldehyde thiosemicarbazone (H₂stsc), and benzaldehyde thiosemicarbazone (Hbtsc), have yielded the complexes, [Ru(pytsc)₂{(p‐tolyl)₃P}₂] ( 2 ), [Ru(Hstsc)₂{(p‐tolyl)₃P}]₂ ( 3 ), and [Ru(btsc)₂{(p‐tolyl)₃P}₂] ( 4 ), respectively. The reactions of precursor Ru₂Cl₄(dppb)₃ {dppb = Ph₂P–(CH₂)₄–PPh₂} with H₂stsc, Hbtsc, furan‐2‐carbaldehyde thiosemicarbazone (Hftsc) and thiophene‐2‐carbaldehyde thiosemicarbazone (Httsc) have formed complexes of the composition, [Ru(Hstsc)₂(dppb)] ( 5 ), [Ru(btsc)₂(dppb)] ( 6 ), [Ru(ftsc)₂(dppb)] ( 7 ), and [Ru(ttsc)₂(dppb)] ( 8 ). The complexes have been characterized by analytical data, IR, NMR (¹H, ³¹P) spectroscopy and X‐ray crystallography ( 1 and 5 ). The proton NMR confirmed loss of –N²H– proton in all the compounds, and ³¹P NMR spectra reveal the presence of equivalent phosphorus atoms in the complexes. In all the compounds, thiosemicarbazone ligands coordinate to the Ru^II atom via hydrazinic nitrogen (N²) and sulfur atoms. The arrangement around each metal atom is distorted octahedral with cis:cis:trans P, P:N, N:S, S dispositions of donor atoms.     

Preparation and characterization of a novel asymmetrically oxidized complex of 2-(diphenylphosphino)-benzenethiol with ruthenium. The crystal and molecular structure of [Ru(2-Ph2PC6H4S)·(2-Ph2PC6H4S−OH)(2-Ph2PC6H4SO2)]·1/2H2O

The reaction between [RuCl₂(PPh₃)₃] and 2-(diphenylphosphino)-benzenethiolate anion (DPPBT) yields the 18-electron Ru^II complex [Ru(DPPBT)₃][HNEt₃] (1), which is readily oxidised first to the neutral Ru^III complex [Ru(DPPBT)₃] (2), and then to the 18 electron Ru^III complex [Ru(2-Ph₂PC₆H₄S)(2-Ph₂PC₆H₄S−OH)·(2-Ph₂PC₆H₄SO₂)]·1/2H₂O (3). The x-ray crystal structure of complex (3) reveals it has a pseudo-octahedral geometry. One sulphur has been oxidised to a sulphinic acid (S−OH) group and a second to a sulphinate (SO₂) group, both being ligatedvia sulphur.     

Reactions of trans-[RuCl2(CO)2(PEt3)2] with 1,1-dithiolates: Stepwise formation of cis-[Ru(CO)(PEt3)(S2X)] (X = CNMe2, CNEt2, COEt,P(OEt)2, PPh2)

Trans-[RuCl₂(CO)₂(PEt₃)₂] reacts with two equivalents of a series of 1,1-dithiolate ligands to form the bis(dithiolate) complexes, cis-[Ru(CO)(PEt₃)(S₂X)₂] (X = CNMe₂, CNEt₂, COEt, P(OEt)₂, PPh₂). Two intermediates have been isolated; trans-[Ru(PEt₃)₂Cl(CO){S₂P(OEt)₂}] and trans-[Ru(PEt₃)₂(CO)(η¹-S₂COEt)(η²-S₂COEt)], allowing a simple reaction scheme to be postulated involving three steps; (i) initial replacement of cis carbonyl and chloride ligands, (ii) substitution of the second chloride, (iii) loss of a phosphine. Thermolysis of cis-[Ru(CO)(PEt₃)(S₂CNMe₂)₂] with Ru₃(CO)₁₂ in xylene affords trinuclear [Ru₃(μ₃-S)₂(PEt₃)(CO)₈] as a result of dithiocarbamate degradation. Crystal structures of cis-[Ru(CO)(PEt₃)(S₂X)₂] (X = NMe₂, COEt), trans-[Ru(PEt₃)₂Cl(CO){S₂P(OEt)₂}], trans-[Ru(PEt₃)₂(CO)(η¹-S₂COEt)(η²-S₂COEt)] and [Ru₃(μ₃-S)₂(PEt₃)(CO)₈] are reported.     

Reactions of Ethyne with Some Ruthenium Cluster Complexes Containing dppm

Reactions of ethyne with [Ru₃(μ‐dppm)(CO)₁₀] have given isomeric complexes [Ru₃(μ₃‐C₆H₆)(CO)₆(dppm)], one of which, 2 , contains the dppm chelating an Ru‐atom, together with a hexatrienetriyl ligand attached to the Ru₃ cluster to form a methylideneruthenacyclohexadiene system. The second isomer 3 contains the dppm bridging an Ru−Ru bond, with the C₆H₆ ligand forming a vinylruthenacyclopentadiene system. Also isolated was the open‐chain Ru₃ complex 4 containing a ruthenacyclopentadiene attached to the central Ru‐atom; the other Ru−Ru vector is bridged by a PPh₂CHPPh₂C₄H₅ ligand, formed by a novel insertion of two ethyne molecules into an Ru−P bond. The reaction of ethyne with [Ru₃(μ‐H)(μ₃‐C₂H₂)(CO)₉] proceeded by attack at the coordinated alkyne and at the cluster to give a cluster‐bonded PPh₂CH₂PPh₂CCH system in 7 . Thermolysis of [Ru₃(μ‐H)(μ₃‐C₂SiMe₃)(μ‐dppm)(CO)₇] ( 8 ; refluxing MeOH) in the presence of KF gave [Ru₆(μ‐CCH₂)₂(μ‐dppm)₂(CO)₁₂] ( 9 ; 80%); similar reactions carried out with [RuClCp(PPh₃)₂] also present gave 9 (67%) together with [Ru₃(μ‐H)(μ₃‐C₂H)(μ‐dppm)(CO)₆(PPh₃)] ( 11 ; 23%). The molecular structures of 2 , 3 , 4 , 7 , 9 , and 11 , some as differently solvated forms, have been determined by single‐crystal X‐ray studies.