Synthesis and structural characterization of [(μ-H)Ru3(CO)8{μ-S(CH2)3SH}(μ-dppe)] and [Ru3(CO)5{μ2-S(CH2)3S}2(η2-dppe)] (dppe=Ph2PCH2CH2PPh2)

The reaction of 1,3-propanedithiol with [Ru₃(CO)₁₀(μ-dppe)] (2) at 66°C afforded the thiolate complexes [(μ-H)Ru₃(CO)₈{μ-S(CH₂)₃SH}(μ-dppe)] (6) and [Ru₃(CO)₅{μ₂-S(CH₂)₃S}₂(η²-dppe)] (7) in 25 and 23% yields respectively. Compound 6 is formed by simple oxidative addition of one of the S–H bonds of 1,3-propanedithiol while the structurally unique 7 consists of an open triruthenium cluster with four terminal and one asymmetrically bridged carbonyl groups, two doubly bridged propanedithiolate ligands and a chelating dppe ligand.     

Synthesis of cis- and trans-[M(CN)2(1-CH3-C6H10-NC)4] (M = Fe,Ru) and crystal structure of trans-[Ru(CN)2(1′-CH3-C6H10-NC)4]

The reaction of the metal carbonyls Fe₂(CO)₉ or Ru₃(CO)₁₂ with 1-isocyano-1-methyl-cyclohexane produces the octahedral metal(II) cyano complexes [M(CN)₂(1-CH₃-C₆H₁₀-NC)₄] in good yields. The cis-isomer is not isolated as a pure compound due to rearrangement processes that yield the sterically less crowded trans-isomer. The molecular structure of the trans-isomer of the ruthenium complex shows the expected almost ideal octahedral coordination of the central ruthenium ion with two cyanide and four isocyanide ligands. This reaction again indicates that isocyanides exhibiting quarternary carbon atoms in α-position with respect to the isocyano substituent in general react with di- or trinuclear metal carbonyls to yield cyano complexes with oxidized metal centres and concomitant reductive cleavage of the respective isocyanide.     

Molecular structure of [In2(μ,η1-OR)(μ,η2-OR)(η2-OR)3(η1-OR)] R = C2H4NMe2, a pincer ligand

Functional indium [In(OR)₃]_m alkoxides (R = C₂H₄OMe, C₂H₄NMe₂) have been obtained by alcoholysis of In[N(SiMe₃)₂]₃ and characterised by elemental analysis, FT-IR and NMR spectroscopy. The 2-dimethylaminoethoxide was characterised by X-ray diffraction. It corresponds to the association of two InO₆ octahedra giving the unsymmetrical dimer [In₂(μ,η¹-OR)(μ,η²-OR)(η²-OR)₃(η¹-OR)] (2). 2 was used as a pincer ligand toward Cu(acac)₂.     

Sulfur-assisted chloride and triphenylphosphine dissociation of palladium(II) complex [Pd(PPh3)2(η1-SCNMe2)(Cl)]. X-ray structures of [Pd(PPh3)2(η1-SCNMe2)(Cl)], [Pd(PPh3)(Cl)]2(μ,η2-SCNMe2)2, and [Pd(PPh3)2(η2-SCNMe2)][PF6]

Treatment of Pd(PPh₃)₄ with Me₂NC(S)Cl in dichloromethane at −20 °C produces the complex [Pd(PPh₃)₂(η¹-SCNMe₂)(Cl)], 2. Variable temperature ¹H and ³¹P{H} NMR experiments of complex 2 shows the dissociation of either the chloride or the triphenylphosphine ligand to form complex [Pd(PPh₃)₂(η²-SCNMe₂)][Cl], 3 or the dipalladium complex [Pd(PPh₃)Cl]₂(μ,η²-SCNMe₂)₂, 4. The reaction of complex 2 with NaPF₆ affords complex [Pd(PPh₃)₂(η²-SCNMe₂)][PF₆], 5. Complexes 2, 4, and 5 are characterized by X-ray diffraction analyses.     

Synthesis and structure of the cubane type [Fe2Sb(CO)5(η5-C5H5)]4 cluster

The [Fe₂Sb(CO)₅Cp]₄ (Cp=η⁵-C₅H₅) cluster has been obtained by the thermolysis of [Et₄N][{Fe(CO)₄}₂{Fe(CO)₂Cp}SbI]. The structure of the [Fe₂Sb(CO)₅Cp]₄·2toluene solvate has been determined by X-ray analysis. The cluster contains the cubane [Fe₄Sb₄] core. Each Sb serves as a μ₄-ligand between three iron atoms of the core and one of a terminal [Fe(CO)₂Cp] group.     

A novel route to titanium compounds containing cyclopentadienyl ligands with bromoethyl substituents; molecular structure of [(η5-C5H4CH2CH2Br)TiBr(μ-O)]4

Compounds (η⁵-C₅H₄CH₂CH₂OCH₃)TiCl₃, (η⁵-C₅H₄CH₂CH₂OCH₃)₂TiCl₂ and (η⁵-C₅H₄CH₂CH₂OCH₃)(η⁵-C₅H₅)TiCl₂ react with BBr₃ to give a high yield of titanium compounds containing cyclopentadienyl ligands with bromoethyl substituents, (η⁵-C₅H₄CH₂CH₂Br)TiBr₃ (1), (η⁵-C₅H₄CH₂CH₂Br)₂TiBr₂ (3) and (η⁵-C₅H₄CH₂CH₂Br)(η⁵-C₅H₅)TiBr₂ (4), respectively. Hydrolysis of 1 in the presence of tert-butylamine affords cyclo-[(η⁵-C₅H₄CH₂CH₂Br)TiBr(μ-O)]₄ (2) in quantitative yield. The molecular structure of 2 was determined by X-ray diffraction.     

Thermal dehydration of Y(TFA)3(H2O)3: Synthesis and molecular structures of [Y(μ,η1:η1-TFA)3(THF)(H2O)]1∞ · THF and [Y4(μ3-OH)4(μ,η1:η1-TFA)6(η1-TFA)(η2-TFA)(THF)3(DMSO)(H2O)] · 6THF (TFA = trifluoroacetate)

In order to obtain a better anhydrous precursor for various applications in materials science and catalysis, thermal dehydration reactions of Y(TFA)₃(H₂O)₃ (TFA = trifluoroacetate) (A) were investigated. Thermal treatment of A at different temperatures under vacuum (5 × 10^?2 mm) for several hours failed to give totally anhydrous yttrium trifluoroacetate (as indicated by IR). Two different complexes, a partially dehydrated [Y(μ,η¹:η¹-TFA)₃(THF)(H₂O)]_1∞·THF (1) and a partially hydrolyzed [Y₄(μ₃-OH)₄(μ,η¹:η¹-TFA)₆(η¹-TFA)(η²-TFA)(THF)₃(DMSO)(H₂O)] · 6THF (2), were obtained with good and moderate yield, respectively, by crystallization of two different thermally treated batches of A from THF (or THF + DMSO) at room temperature. More efficient dehydration of A could be achieved at 200 °C in a furnace, the obtained anhydrous yttrium tris-trifluoroacetate giving Y(TFA)₃(THF)₂ (3) on crystallization from THF. All the products were characterized by elemental analyses, FT-IR and ¹H NMR spectroscopy as well as thermo-gravimetric analysis. In addition, single crystal X-ray structures are reported for 1 and 2, which show either a terminal (η¹ and η²) or bridging (μ,η¹:η¹) bonding behavior of the TFA ligand.     

Phosphorus–carbon bond cleavage of Ph2PCH2PPh2 at a triruthenium center: synthesis and structural characterization of [Ru3(μ-CO)(CO)6(μ-PPh2)2(μ3-CH2PPh)]

The reaction of Ph₂PH with [Ru₃(CO)₁₀(μ-dppm)] (1) at 98°C gave [Ru₃(μ-CO)(CO)₆(μ-PPh₂)₂(μ₃-CH₂PPh)] (7) in 20% yield. Compound 7 was characterized by elemental analysis, ¹H and ³¹P{¹H} NMR and mass spectroscopic data and also by a single crystal structure determination. The compound is shown to consist of a triruthenium cluster with an unusual example of a triply bridging CH₂PPh ligand and two doubly bridging PPh₂ ligands.     

A convenient method for the synthesis of [Pd{[(η5-C5H3)–CHN–(CH2)2–NMe2]Fe(η5-C5H5)}Cl] and the study of its reactivity with diphosphines

A one-pot method for the preparation of [Pd{[(η⁵-C₅H₃)–CHN–(CH₂)₂–NMe₂]Fe(η⁵-C₅H₅)}Cl] is described. Its X-ray crystal structure and its reactions with the diphosphines Ph₂P–(CH₂)_n–PPh₂ {with n=1 (ddpm) or 2 (dppe)} are also reported.     

[Ru(CO)(CH3CO2)(tpa)]ClO4·C6H5CH3 (tpa=tris(2-pyridylmethyl)amine), the first ruthenium carbonyl complex of tpa

The reaction of dodecacarbonyltriruthenium with tris(2-pyridylmethyl)ammonium perchlorate (tpa·3HClO₄), in the presence of acetic acid, afforded a new ruthenium complex of tpa, [Ru(CO)(CH₃CO₂)(tpa)]ClO₄·C₆H₅CH₃ (1). Compound 1 has been characterized by X-ray structural analysis, IR and ¹H NMR spectra.     

Cyclohexadiene-linked clusters: synthesis and molecular structure of [{Os4(CO)8(MeCCMe)(η6-C6H6)}2(μ2-η2:η2-C6H8-1,3)]

The reaction of [Os₄(CO)₉(RCCR)(η⁶-C₆H₆)] (R=Me, Ph) with Me₃NO in the presence of 1,3-cyclohexadiene or 1,4-cyclohexadiene yields the clusters [{Os₄(CO)₈(RCCR)(η⁶-C₆H₆)}₂(μ₂-η²:η²-C₆H₈-1,3)] and [{Os₄(CO)₈(RCCR)(η⁶-C₆H₆)}₂(μ₂-η²:η²-C₆H₈-1,4)], respectively. The molecular structure of [{Os₄(CO)₈(MeCCMe)(η⁶-C₆H₆)}₂(μ₂-η²:η²-C₆H₈-1,3)] has been determined by single crystal X-ray diffraction, and represents the first example of two osmium cluster fragments linked by 1,3-cyclohexadiene through a μ₂-η²:η²-bridge.     

Six- and five-coordinated complexes of Co(II) with 2-(2′-pyridyl)quinoxaline. Crystal structures of the complexes [CoLCl2(DMF)] and [CoL2(H2O)2](ClO4)2·H2O·2CH3OH

Reaction of Co(II) perchlorate hexahydrate and anhydrous Co(II) chloride with the ligand 2-(2′-pyridyl)quinoxaline (L) leads to the formation of the novel five- and six-coordinated complexes CoLCl₂(DMF) (1) and [CoL₂(H₂O)₂](ClO₄)₂·H₂O·2CH₃OH (2), correspondingly. The crystal structures of the above complexes show a trigonal bipyramidal geometry around the metal atom for complex 1 and a distorted octahedral geometry for complex 2.     

Formation of [8,8-η2-{(μ-Cl)2Ru(η6-p-cym)Ph2PCH2PPh2}-nido-8,7-RhSB9H10], a bimetallic derivative of the novel species [8,8-(η2-dppm)-8-(η1-dppm)-nido-8,7-RhSB9H10]

Treatment of [8,8-(η²-dppm)-8-(η¹-dppm)-nido-8,7-RhSB₉H₁₀] (I) with [Ru(η⁶-p-cym)Cl₂]₂ leads to the formation of a new bimetallic complex, [8,8-η²-{(μ-Cl)₂Ru(η⁶-p-cym)Ph₂PCH₂PPh₂}-nido-8,7-RhSB₉H₁₀], (II) containing the group [(μ-Cl)₂Ru(η⁶-p-cym)Ph₂PCH₂PPh₂] that coordinates in a multidentate mode to Rh.     

A new lead(II) inorganic–organic hybrid of the P,P′-diphenylmethylene-diphosphinate ligand: synthesis and X-ray characterization of the [Pb(CH2(P(Ph)O2)2)] complex

By reaction of lead(II) nitrate with P,P^′-diphenylmethylenediphosphinic acid in water solution a new inorganic–organic hybrid of formula [Pb(CH₂(P(Ph)O₂)₂)] has been synthesized and structurally characterized. The complex displays a polymeric columnar structure, the column being formed by two intersecting sinusoidal ribbons of lead(II) ions bridged by bifunctional phosphinate ligands. The intersections of the ribbons are constituted by dimeric units of pentacoordinated lead(II) ions.     

Reactivity of [WCl(SnCl3)(CO)3(NCMe)2] towards tBuCCH.: X-ray crystal structure of [WCl(CO)(tBuCCH)(NCMe)(PPh3)2]2[SnCl6]

In the reaction of [WCl(SnCl₃)(CO)₃(NCMe)₂] with tert-butylacetylene the very labile bis(alkyne) complex [WCl(SnCl₃)(CO)(^tBuCCH)₂(NCMe)] has been observed as the major product by means of IR and NMR spectroscopy. The latter compound in reaction with two equivalents of PPh₃ in CH₂Cl₂ solution gives very poorly soluble purple crystals of the tungsten(II) cationic complex. The crystal structure of this compound consists of the discrete [SnCl₆]²⁻ anion, two independent [WCl(CO)(^tBuCCH)(NCMe)(PPh₃)₂]⁺ cations and four MeCN (solvent) molecules. This is the first crystallographically characterized cationic chlorocarbonyl complex of tungsten(II) containing a terminal alkyne as ligand.     

Synthesis and Structure of New Dimeric Cyclopentadienyl Titanium Fluorine–Oxygen Systems: [Cp*TiF(μ-F)(μ-OPOPh2)]2, [Cp*TiF(μ-F)(μ-OSO2-p-C6H4Me)]2 and [Cp*TiF2(μ-OMe)]2

The reactions of Cp*TiF₃ with Me₃SiOPOPh₂, Me₃SiOSO₂-p-C₆H₄Me, and Al(OMe)₃ resulted in the formation of the dimers [Cp*TiF(μ-F)(μ-OPOPh₂)]₂ 1 , [Cp*TiF(μ-F)(μ-OSO₂-p-C₆H₄Me)]₂ 2 , and [Cp*TiF₂(μ-OMe)]₂ 3 , respectively, in good yields. In contrast to the formation of 3 , Cp*TiF₃ reacts with Al(OH)₃ to afford the known tetramer [Cp*TiF(μ-O)]₄ 4 . The structures of 1–3 have been determined by X-ray crystallography; compounds 1 and 3 crystallize in the monoclinic space group P2₁/c and compound 2 in the monoclinic space group P2/n. Compound 1 is the first example of a dimeric Cp*-titanium phosphinate containing a fluorine ligand. The core of the dimeric structure of both 1 and 2 consists of two Ti atoms bridged by two fluorine atoms and two bidentate groups. In contrast, the dimeric structure of 3 consists of two Ti atoms bridged only by two methoxy groups. An equilibrium of isomers of 1 and 2 has been observed in solution by ¹H and ¹⁹F NMR. The ¹⁹F NMR spectra of 1–3 are discussed in detail.