New heterodimetallic cyclopentadienyl carbonyl complexes: crystal structure of (C5Me4Et)(μ-CO)3Ru(C5Me5)

A series of heterodimetallic complexes of general formula (C₅R₅)M(μ-CO)₃RuC₅Me₅ (M = Cr, Mo, W; R = Me, Et) has been prepared in good yields by the reaction of [C₅R₅M(CO)₃]⁻ with [C₅Me₅Ru(CH₃CN)₃]⁺. (C₅Me₄Et)W(μ-CO)₃Ru(C₅Me₅) was characterized by a crystal structure determination. The W---Ru bond length of 2.41 Å is consistent with the formulation of a metal-metal triple bond, while the unsymmetrical bonding mode of the three bridging carbonyl groups reflects the inherent non-equivalence of the two different C₅R₅M-units. Using [CpRu(CH₃CN)₃]⁺ or [CpRu(CO)₂(CH₃CN)]⁺ as the cationic precursor leads to the formation of dimetallic species (C₅R₅)M(CO)₅RuC₅H₅ with both bridging and terminal carbonyl groups.     

Synthesis and crystal structure of the complex [MoW(OEt)(μ-CH2){μ-C(C6H4Me-4)C(Me)O}(η-C7H7)(η-C2B9H10Me)]

The complex [MoW(μ-CC₆H₄Me-4)(CO)₂(η⁷-C₇H₇)(η⁵-C₂B₉H₁₀Me)] reacts with diazomethane in Et₂O containing EtOH to afford the dimetal compound [MoW(OEt)(μ-CH₂){μ-C(C₆H₄Me-4)C(Me)O}(η⁷-C₇H₇)(η⁵-C₂B₉H₁₀Me)]. The structure of this product was established by X-ray diffraction. The Mo---W bond [2.778(4) Å] is bridged by a CH₂ group [μ-C---Mo 2.14(3), μ-C---W 2.02(3) Å] and by a C(C₆H₄Me-4)C(Me)O fragment [Mo---O 2.11(3), W---O 2.18(2), Mo---C(C₆H₄Me-4) 2.41(3), W---C(C₆H₄Me-4) 2.09(3), Mo---C(Me) 2.26(3) Å]. The molybdenum atom is η⁷-coordinated by the C₇H₇ ring and the tungsten atom is η⁵-coordinated by the open pentagonal face of the nido-icosahedral C₂B₉H₁₀Me cage. The tungsten atom also carries a terminally bound OEt group [W---O 1.88(3) Å]. The ¹H and ¹³C-{¹H} NMR data for the dimetal compound are reported and discussed.     

Reactions of Ru(CCPh)(L2)Cp* (L2=dppm, dppe) with tetracyanoethene: cycloaddition, formation of monodentate dppm and dppmO complexes and migration of CN to ruthenium

Reactions of FcCCH (a), HCCCCFc (b) and FcCCCCFc (c) with Ru₃(CO)₁₀(NCMe)₂ (all) and Ru₃(μ-dppm)(CO)₁₀ (b and c only) are described. Among the products, the complexes Ru₃(μ₃-RC₂R′)(μ-CO)(CO)₉ (R=H, R′=Fc 1, CCFc 2; R=R′=Fc 5), Ru₃(μ-H)(μ₃-C₂CCFc)(μ-dppm)(CO)₇ 3, Ru₃(μ₃-FcC₂CCFc)(μ-dppm)(μ-CO)(CO)₇ 6 and Ru₃{μ₃-C₄Fc₂(CCFc)₂}(μ-dppm)(μ-CO)(CO)₅ 7 were characterised, including single-crystal structure determinations for 1, 3, 5 and 7; that of 7 did not differ significantly from an earlier study of a mixed CH₂Cl₂–C₆H₆ solvate.     

Synthesis and structure of ansa-cyclopentadienyl pyrrolyl titanium complexes: [(η-C5H4)CH2(2-C4H3N)]Ti(NMe2)2 and [1,3-{CH2(2-C4H3N)}2(η-C5H3)]Ti(NMe2)

Reaction of ansa-cyclopentadienyl pyrrolyl ligand (C₅H₅)CH₂(2-C₄H₃NH) (2) with Ti(NMe₂)₄ affords bis(dimethylamido)titanium complex [(η⁵-C₅H₄)CH₂(2-C₄H₃N)]Ti(NMe₂)₂ (3) via amine elimination. A cyclopentadiene ligand with two pendant pyrrolyl arms, a mixture of 1,3- and 1,4-{CH₂(2-C₄H₃NH)}₂C₅H₄ (4), undergoes an analogous reaction with Ti(NMe₂)₄ to give [1,3-{CH₂(2-C₄H₃N)}₂(η⁵-C₅H₃)]Ti(NMe₂) (5). Molecular structures of 3 and 5 have been determined by single crystal X-ray diffraction studies.     

Highly stereoselective reduction of methyl ketone complexes of the chiral Lewis acid [(η-C5H5)Re(NO)(PPh3)] by K(s-C4H9)3BH; synthesis of optically active secondary alcohols and derivatives

Reaction of optically active ketone complexes (+)-(R)-[(η⁵-C₅H₅)Re(NO)-(PPh₃)(η¹-O=C(R)(CH₃)]⁺ BF₄⁻ (R = CH₂CH₃, CH(CH₃)₂m C(CH₃)₃, C₆H₅) with K(s-C₄H₉)₃BH gives alkoxide complexes (+)-(RS)-(η⁵-C₅H₅)Re(NO)(PPh₃)-(OCH(R)CH₃) (73–90%) in 80–98% de. The alkoxide ligand is then converted to Mosher esters (93–99%) of 79–98% de.     

Synthesis of Tc(IV) alcoholato complexes with methanol, ethyleneglycol and 1,2,4-butanetriol

The preparation of three Tc(IV) alcoholato complexes: K₂[⁹⁹Tc(OMe)₆], K₂[⁹⁹Tc(glyc)₃·3C₂H₅OH (H₂glyc = CH₂OHCH₂OH), and K₂[⁹⁹Tc(butri)₂]·CH₃OH (H₃butri = CH₂OHCHOHCH₂CH₂OH) is described.     

Ethylene hydrogenation by the hydride alkoxide species Ir(H)2(OCH2CF3)(PBu2Ph)2. Ethylene-induced reductive elimination of alcohol from Ir

Ir(H)₂(OR_f)P₂ (P = P^tBu₂Ph, R_f = CH₂CF₃) reacts with ethylene at 25°C to give R_fOH, ethane and Ir(P C)P(C₂H₄) (2) then Ir(P C)(C₂H₄)₂ (1) and Ir(P C)H(OR_f)P (3) (P C = η²-C₆H₄P^tBu₂). It is shown that 2 and 1 are in equilibrium by P and C₂H₄ addition/dissociation. Compound 3 is a product “late” in the reaction sequence, and results from H---OR_f oxidative addition to 2. Since 3 reacts with ethylene to give 2, 2 and 3 are in thermal equilibrium. Compound 3 reacts readily with H₂ to give IrH₅P₂ and R_fOH. The reason why OR_f and ethylene ligands seem to be mutually incompatible is discussed.     

Studies of N-heterocyclic compounds with triosmium clusters: Formation of the heterocyclic-linked dicluster compound [Os 6(μ-H)2(μ3-C6H4N3)2(CO)18]

The cluster [Os₃(CO)₁₀(MeCN)₂] reacts with indazole (C₇H₆N₂) to give two isomeric products [0s₃(μ-H)(μ-C₇H₅N₂)(CO)₁₀] in which the five-membered ring has been metallated with N-H cleavage to give an N,N-bonded isomer or with C-H cleavage to give a C,N-bonded isomer. These two isomers have very similar X-ray structures but can be clearly distinguished by ¹H NMR methods. They are shown to correspond to related clusters derived from pyrazole. Benzotriazole (C₆H₅N₃) also reacts (as shown earlier by others) to give two isomers: an N,N-bonded species [Os₃(μ-H)(μ-C₆H₄N₃)(CO)₁₀] coordinated only through the five-membered ring and a minor C,N-bonded isomer [Os₃(μ-H)(μ-C₆H₄N₃)(CO)₁₀], metallated at the C₆ ring and coordinated through both rings. The former isomer reacts with Me₃NO in acetonitrile to give [Os₃(μ-H)(μ-C₆H₄N₃)(CO)₉(MeCN)] which thermally looses MeCN to produce the coupled product [Os₆(μ-H)₂(μ₃-C₆H₄N₃)₂(CO)₁₈] which was shown by X-ray structure determination to have all six nitrogen atoms coordinated to osmium, a novel situation for coordinated benzotriazole. The two Os₃ units are linked together by an OsNNOsNN ring in a boat conformation with the whole cluster adopting C₂ symmetry.     

Interaction of half-sandwich alkylmolybdenum(III) complexes with B(C6F5)3. The X-ray structure of [CpMo(η-C4H6)(μ-Cl)(μ-CH2)(O)MoCp][CH3B(C6F5)3]

The reactions of the half-sandwich molybdenum(III) complexes CpMo(η⁴-C₄H₄R₂)(CH₃)₂, where Cp=η⁵-C₅H₅ and R=H or CH₃, with equimolar amounts of B(C₆F₅)₃ have been investigated in toluene. EPR monitoring shows the formation of an addition product which does not readily react with Lewis bases such as ethylene, pyridine, or PMe₃. The analysis of the EPR properties and the X-ray structure of a decomposition product obtained from dichloromethane, [CpMo(η⁴-C₄H₆)(μ-Cl)(μ-CH₂)(O)MoCp][CH₃B(C₆F₅)₃], indicate that the borane attack has occurred at the methyl position.     

The first tetranuclear vanadium(V) peroxo complex: Preparation, vibrational spectra and X-ray crystal structure of K6[V4O4(O2)8(PO4)]·9H2O

The vanadium(V) peroxo phosphato complex K₇[V₄O₄(O₂)₈(PO₄)]·9H₂O has been obtained from the KVO₃---KH₂PO₄---KOH---H₂O₂---H₂O---C₂H₅OH system. The X-ray structural analysis revealed a tetranuclear anionic structure in which two dinuclear [V₂O₂(O)₂)₂(μ-η¹ : η²-O₂)₂] units are connected by the μ₄-PO₄ group.     

Reaction of [(C6H6)RuCl2]2 with 7,8-benzoquinoline and 8-hydroxyquinoline

The reaction of [(C₆H₆)RuCl₂]₂ with 7,8-benzoquinoline and 8-hydroxyquinoline in methanol were performed. The obtained complexes have been studied by IR, UV–VIS, ¹H and ¹³C NMR spectroscopy and X-ray crystallography. In the reaction with 8-hydroxyquinoline the arene ruthenium(II) complex oxidized to Ru(III). The electronic spectra of the obtained compounds have been calculated using the TDDFT method. Magnetic properties of [Ru(C₉H₆NO)₃] · CH₃OH complex suggest the antiferromagnetic coupling of the ruthenium centers in the crystal lattice. EPR spectrum of [Ru(C₉H₆NO)₃] · CH₃OH compound indicates single isotropic line only characteristic for Ru³⁺ with spin equal to 1/2.     

Reactions of the cationic diruthenium carbonyl complex [Ru2(μ-dppm)2(CO)4(μ,η-O2CMe)] with bidentate ligands; intramolecularly assisted stereospecific synthesis via the second-sphere face-to-face π–π stacking interactions

The reactions of the diruthenium carbonyl complexes [Ru₂(μ-dppm)₂(CO)₄(μ,η²-O₂CMe)]X (X=BF₄⁻ (1a) or PF₆⁻ (1b)) with neutral or anionic bidentate ligands (L,L) afford a series of the diruthenium bridging carbonyl complexes [Ru₂(μ-dppm)₂(μ-CO)₂(η²-(L,L))₂]X_n ((L,L)=acetate (O₂CMe), 2,2′-bipyridine (bpy), acetylacetonate (acac), 8-quinolinolate (quin); n=0, 1, 2). Apparently with coordination of the bidentate ligands, the bound acetate ligand of [Ru₂(μ-dppm)₂(CO)₄(μ,η²-O₂CMe)]⁺ either migrates within the same complex or into a different one, or is simply replaced. The reaction of [Ru₂(μ-dppm)₂(CO)₄(μ,η²-O₂CMe)]⁺ (1) with 2,2′-bipyridine produces [Ru₂(μ-dppm)₂(μ-CO)₂(η²-O₂CMe)₂] (2), [Ru₂(μ-dppm)₂(μ-CO)₂(η²-O₂CMe)(η²-bpy)]⁺ (3), and [Ru₂(μ-dppm)₂(μ-CO)₂(η²-bpy)₂]²⁺ (4). Alternatively compound 2 can be prepared from the reaction of 1a with MeCO₂H–Et₃N, while compound 4 can be obtained from the reaction of 3 with bpy. The reaction of 1b with acetylacetone–Et₃N produces [Ru₂(μ-dppm)₂(μ-CO)₂(η²-O₂CMe)(η²-acac)] (5) and [Ru₂(μ-dppm)₂(μ-CO)₂(η²-acac)₂] (6). Compound 2 can also react with acetylacetone–Et₃N to produce 6. Surprisingly [Ru₂(μ-dppm)₂(μ-CO)₂(η²-quin)₂] (7) was obtained stereospecifically as the only one product from the reaction of 1b with 8-quinolinol–Et₃N. The structure of 7 has been established by X-ray crystallography and found to adopt a cis geometry. Further, the stereospecific reaction is probably caused by the second-sphere π–π face-to-face stacking interactions between the phenyl rings of dppm and the electron-deficient six-membered ring moiety of the bound quinolinate (i.e. the N-included six-membered ring) in 7. The presence of such interactions is indeed supported by an observed charge-transfer band in a UV–vis spectrum.     

The evaluation of singlet-triplet separations for [W2(μ-H)(μ-Cl)Cl4(μ-dppm)2] and [W2(μ-H)2 (μ-O2CC6H5)2(P(C6H5)3)2] based on P NMR and crystallographic data

The singlet-triplet separations for the edge-sharing bioctahedral (ESBO) complex W₂(μ-H)(μ-Cl)(Cl₄(μ-dppm)₂ · (THF)₃ (II) has been studied by ³¹P NMR spectroscopy. The structural characterization of [W₂(μ-H)₂(μ-O₂CC₆H₅)₂Cl₂(P(C₆H₅)₃)₂] (I) by single-crystal X-ray crystallography has allowed the comparison of the energy of the HOMOLUMO separation determined using the Fenske-Hall method for a series of ESBO complexes with two hydride bridging atoms, two chloride bridging atoms and the mixed case with a chloride and hydride bridging atom. The complex representing the mixed case, [W₂(μ-H)(μ-Cl)Cl₄(μ-dppm)₂ · (THF)₃] (II), has been synthesized and the value of −2J determined from variable-temperature ³¹P NMR spectroscopy.     

Crystal Structure, Nano-particle Morphology and Interaction with ATP of [ NH3 CH2 CH（ NH2 ） CH3 ]2 [ M（ Ⅵ ） O2 （ OC6 H4 O）2 ] （M = Mo0. 6 W0. 4 ） and Its Activity to Promote DNA Cleavage

The title complex [NH_3CH_2CH(NH_2)CH_3]_2 [M(Ⅵ)O_2(OC_6H_4O)_2](M= Mo_(0.6)W_(0.4))was synthesized via a simple solution-phase chemical route.The determination of single crystal X-ray diffraction revealed that the title compound is crystallized in a monoclinic system with P2(1)/n space group,a=1.0913(10)nm,b=1.0442(10)nm,c=1.8842(19)nm,α=90°,β=96.530(17)°,γ=90°,Z=4,and V=2.133(4)nm3.The mononuclear anionic unit [M(Ⅵ)O2(OC6H4O)2]2-displays chiral pseudo-octahedral [MO_6] coordination geometry and is linked by chiral cations via hydrogen bond and π…π stacking interaction.The transmission electron microscopy images show that the title complex is comprised of nano-particles with diameters ranging from 20 to 50 nm.The NMR study shows the 1H downfield chemical shifts of [NH_3CHaHbCH(NH_2)CH_3] cations in the title complex when it is mixed with adenosine-triphosphate(ATP),and the chemical shift difference between Ha and Hb is increased greatly,and most of the catecholate ligands dissociate from the central metal atoms.The DNA cleavage activity experiment reveals that DNA cleavage promoted by the title complex is lower than that by Na_2MoO_4 which possesses antitumor pro-perty,but higher than that by Na_2WO_4.     

Synthesis and crystal structure of the novel trimanganese tetrathiolate incomplete cubane: [Mo(η-C5H5)2(H)CO][Mn3(CO)9(μ-SC6H5)4]

An unexpected trimanganese(I) tetrathiolate-bridged complex, [Mn₃(CO)₉(μ-SC₆H₅)₄]⁻, with an incomplete cubane structure, was obtained by thermal reaction of [Mn₂(CO)₁₀] with [Mo(η⁵-C₅H₅)₂(SC₆H₅)₂]. The structure, established by single-crystal X-ray diffraction studies, shows the cation, [Mo(η⁵-C₅H₅)₂(H)CO]⁺, directed towards the vacant site of the cubane structure. Possible routes by which the anion and the cation could be formed are discussed.     

New rhodium---ruthenium heterobimetallic complexes with bridging bi- or tri-dentate phosphine ligands

The mononuclear chelated complex [RuCl(Cp)(η²-dppa)] has been synthesised and reacted with [Rh₂Cl₂(CO)₄] to form the heterobimetallic complex [(Cp)Ru(μ-CO)₂{(μ-Ph₂PN(H)PPh₂}RhCl₂]. Complexes of [RuCl(Cp){(PPh₂)₂CHCH₂PPh₂}] have been reacted with [Rh₂Cl₂(CO)₄] or [RhCl(CO)₂(p-toluidene)]. Characterisation of these new ruthenium complexes was carried out using ³¹P-NMR, FAB mass spectroscopy, elemental analysis and IR spectrophotometry.     

Stability of the silicon-ruthenium bond in the presence of a strong nucleophile. Phase sensitive H NMR COSY and crystal structure of Ru(CO)2(NH2CH2C6H5)2(Si(C6H5)(CH3)2)I

The ruthenium(II) complex Ru(CO)₂(NH₂(NH₂CH₂C₆H₅)₂(Si(C₆H₅)(CH₃)₂)I has been prepared by the reaction of Ru(CO)₄(Si(C₆H₅)(CH₃)₂)I with benzylamine. Two-dimensional homonuclear ¹H NMR experiments examine the scalar coupling of the enantiotopic amino and methylene protons of the benzylamine ligand. X-ray analysis of Ru(CO)₂(NH₂CH₂C₆H₅)₂(Si(C₆H₅)(CH₃)₂)I·1/3C₅H₁₂ (triclinic; P ; a = 14.266(4), b = 15.748(5), c = 20.082(6) Å; = 94.38(3), β = 96.30(2), γ = 101.52(2)°) indicates three crystallographically unique complexes form a clathrate with a pentane guest.     

Double bond shifts induced by reaction of hex-5-en-2-one with triosmium clusters

Carbon---hydrogen bond cleavage at the terminal 6-position occurs when hex-5-en-2-one (CH₂=CHCH₂CH₂COMe) oxidatively adds to [Os₃(CO)₁₀(MeCN)₂] to give [Os₃H(μ-CH=CHCH₂CH₂COMe)(CO)₁₀], which is completely analogous to the simple vinyl complex [Os₃H(μ-CH=CH₂)(CO)₁₀]. A minor product from the reaction is [Os₃(CH₃CH=CHCH₂COMe)(CO)₁₀], an isomer in which double-bond migration has occurred to give the βγ-unsaturated ketone; stabilisation occurs through chelation and ketone coordination. [Os₃H₂(CO)₁₀] reacts with CH₂=CHCH₂CH₂COMe in refluxing cyclohexane to give a third isomer, [Os₃H(CH₃CH₂C=CHCOMe)(CO)₁₀], in which further double bond migration has occurred to give the β-unsaturated ketone. Metallation at the β-site gives an Os---C bond as part of a 5-membered chelate ring. Thermolysis of each of the three isomeric decarbonyl species in refluxing cyclohexane or heptane leads to the elimination of an Os(CO)₄ group to give the dinuclear compound [Os₂H(EtC=CHCOMe)(CO)₆] in varying yield. Pathways from γδ to the βγ and finally the β unsaturated ketones may be mapped out.     

Macrocyclic gold(I) complexes and [2]catenanes containing carbonyl functionalized diacetylide ligands

The carbonyl derivatized bis(alkyne) O=C(4-C₆H₄OCH₂CCH)₂ was converted into the imine derivatives RN=C(4-C₆H₄OCH₂CCH)₂ [R=OH, NHC(O)NH₂, NHC₆H₃-2,4-(NO₂)₂] and into the 4-bromomethyl-1,3-dioxolane derivative BrCH₂C₂H₃O₂C(4-C₆H₄OCH₂CCH)₂. The alkyne units in these compounds react with [AuCl(SMe₂)] in the presence of base to form the corresponding digold(I) diacetylide complexes, that exist as insoluble oligomers or polymers. They reacted with the diphosphines Ph₂PZPPh₂ [Z=CC, trans-HC=CH and (CH₂)_n, n=3–5] to give macrocyclic gold(I) complexes of the type [Au₂(μ-LL)(μ-PP)], where LL is the diacetylide and PP the diphosphine ligand. The ability of these macrocyclic complexes to self-assemble to [2]catenanes has been studied. The ketone and imine derivatives do not form [2]catenanes because the orientation of the aryl groups is unfavorable, but the 1,3-dioxolane derivatives may catenate if the ring size is optimum.     

Synthesis and X-ray crystal structures of [Ph2PMe2][(η-C5H4Bu)2Li] and [(η-C5H4Bu)2Yb(Cl)CH2P(Me)Ph2]

The interaction of [(η⁵-C₅H₄Bu^t)₂YbCl · LiCl] with one equivalent of Li[(CH₂) (CH₂)PPh₂] in tetrahydrofuran gave [Ph₂PMe₂][(η⁵-C₅H₄Bu^t)₂Li] (1) and [(η⁵-C₅H₄Bu^t)₂Yb(Cl)CH₂P(Me)Ph₂] (2) in 10% and 30% yields, respectively. 1 could also be prepared in 70% yield from the reaction of [Ph₂PMe₂][CF₃SO₃] with two equivalents of (C₅H₄Bu^t)Li. Both compounds have been fully characterized by analytical, spectroscopic and X-ray diffraction methods. The solid state structure of 1 reveals a sandwich structure for the [(η⁵-C₅H₄Bu^t)₂Li]⁻ anion.