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.     

Substituted cyclopentadienyl ligands—10. Intramolecular steric interactions in [(η-C5H3(SiMe3)2)Mo(CO)2(L)I]

Reaction of C₅H₄(SiMe₃)₂ with Mo(CO)₆ yielded [(η⁵-C₅H₃(SiMe₃)₂)Mo(CO)₃]₂, which on addition of iodine gave [(η⁵-C₅H₃(SiMe₃)₂Mo(CO)₃I]. Carbonyl displacement by a range of ligands: [L = P(OMe)₃, P(OPrⁱ)₃,P(O-o-tol)₃, PMe₃, PMe₂Ph, PMePh₂, PPh₃, P(m-tol)₃] gave the new complexes [(η⁵-C₅H₃(SiMe₃)₂ MO(CO)₂(L)I]. For all the trans isomer was the dominant, if not exclusive, isomer formed in the reaction. An NOE spectral analysis of [(η⁵-C₅H₃(SiMe₃)₂)Mo(CO)₂(L)I] L = PMe₂Ph, P(OMe)₃] revealed that the L group resided on the sterically uncongested side of the cyclopentadienyl ligand and that the ligand did not access the congested side of the molecule. Quantification of this phenomenon [L = P(OMe)₃] was achieved by means of the vertex angle of overlap methodology. This methodology revealed a steric preference with the trans isomer (less congestion of CO than I with an SiMe₃ group) being the more stable isomer for L = P(OMe)₃.     

Synthesis and X-ray structure of (η-C5H5)2W2Ir2(CO)7(CHCO2Et)2, a tetrahedral heterometal cluster with two different environments for ethylcarboxylatocarbene ligands

The tetrahedral heteronuclear cluster complex (η⁵-C₅H₅)₂W₂Ir₂(CO)₁₀ reacts with N₂CHCO₂R (R = Et, Me) at room temperature to form the dicarbene species (η⁵-C₅H₅)₂W₂Ir₂(CO)₇(CHCO₂R)₂. An X-ray diffraction study (R = Et) shows an intact tetrahedral metal framework with two distinct sites for the CHCO₂Et ligands. The first uses its carbon atom to bridge the Ir---Ir bond; the second uses its carbon atom to bridge an Ir---W bond and, additionally, forms a donor bond from a carbonyl oxygen atom to the second tungsten atom.     

An unexpected molybdenum(0) complex with “MoP6” coordination: crystal structure of [Mo{P(CH2CH2PPh2)3}2] · C5H10

The reaction of trans-[Mo(N₂)₂(PPh₂Me)₄] with the tripodal phosphine tris(2-diphenylphosphinoethyl)phosphine, PP₃, in benzene has been studied. The product was recrystallized from a mixture of benzene and petroleum ether to give [Mo(PP₃)₂]·C₅H₁₀, whose crystal structure shows a distorted octahedral “MoP₆” coordination with both phosphines acting as tridentate ligands.     

Synthesis and structure of the iron-substituted silylacetylene [(η-C5H5)Fe(CO)2SiMe2C]2 and its cobalt hexacarbonyl derivative [(η-C5H5)Fe(CO)2SiMe2C]2 · Co2(CO)6

A transition metal-substituted silylacetylene [(η⁵-C₅H₅)Fe(CO)₂SiMe₂C]₂, [FpMe₂SiC]₂ (I) was synthesized and characterized spectroscopically and structurally. I crystallized in the monoclinic space group P2₁/n, A = 13.011(3) Å B = 12.912(3) Å, C = 13.175(5) Å, β = 94.95(2). The acetylene linkage is reactive toward Co₂(CO)₈ to form I. Co₂(CO)₆ (II) which was also characterized spectroscopically and by single crystal X-ray diffraction. II crystallized in the orthorhombic space group Pbca, A = 17.64(2) Å, B = 14.225(10) Å, C = 24.49(2) Å.     

Synthesis and characterization of Na5[Co(CO)3(P{(CH2)nC6H4-P-SO3}3)2], n = 1, 2, 3, and 6. Novel zwitterion

The electron donating water soluble phosphines, P{(CH₂)nC₆H₄-p-SO₃Na}₃,n = 1, 2, 3 and 6, react rapidly with Co₂(CO)₈ under two phase reaction conditions to yield the disproportionation products, [Co(CO)₃(P{(CH₂)nC₆H₄-p-SO₃Na₃}₂] [Co(CO)₄]. Selective precipitation yields the formally zwitterionic complex anions as the sodium salt, [Co(CO)₃(P{(CH₂)nC₆H₄-p-SO₃} ₃)₂]⁵⁻. The anions can be used as precursors to water soluble cobalt hydroformylation catalysts under two phase and supported aqueous phase conditions. The tendency to form alcohol products is low with these complexes. The behavior of the catalysts is consistent with an active species that remains water soluble during the reaction and is not leached into the nonaqueous phase.     

Synthesis of metallocenes of zirconium, hafnium, manganese, iron, tin, lead and half-sandwich complexes of rhodium and iridium containing the ligands (η-C5R4CR′2PMe2), where R and R′ may be H or Me

The dimethylphosphino substituted cyclopentadienyl precursor compounds [M(C₅Me₄CH₂PMe₂)], where M=Li⁺ (1), Na⁺ (2), or K⁺ (3), and [Li(C₅H₄CR′₂PMe₂)], where R′₂=Me₂ (4), or (CH₂)₅ (5), [HC₅Me₄CH₂PMe₂H]X, where X⁻=Cl⁻ (6) or PF₆⁻ (7) and [HC₅Me₄CH₂PMe₂] (8), are described. They have been used to prepare new metallocene compounds, of which representative examples are [Fe(η-C₅R₄CR′₂PMe₂)₂], where R=Me, R′=H (9); R=H and R′₂=Me₂ (10), or (CH₂)₅ (11), [Fe(η-C₅H₄CMe₂PMe₃)₂]I₂ (12), [Fe{η-C₅Me₄CH₂P(O)Me₂}₂] (13), [Zr(η-C₅R₄CR′₂PMe₂)₂Cl₂], where R=H, R′=Me (14), or R=Me, R′=H (15), [Hf(η-C₅H₄CMe₂PMe₂)₂]Cl₂] (16), [Zr(η-C₅H₄CMe₂PMe₂)₂Me₂] (17), {[Zr(η-C₅Me₄CH₂PMe₂)₂]Cl}{(C₆F₅)₃BClB(C₆F₅)₃} (18), [Zr{(η-C₅Me₄CH₂PMe₂)₂Cl₂}PtI₂] (19), [Mn(η-C₅Me₄CH₂PMe₂)₂] (20), [Mn{(η-C₅Me₄CH₂PMe₂B(C₆F₅)₃}₂] (21), [Pb(η-C₅H₄CMe₂PMe₂)₂] (23), [Sn(η-C₅H₄CMe₂PMe₂)₂] (24), [Pb{η-C₅H₄CMe₂PMe₂B(C₆F₅)₃}₂] (25), [Pb(η-C₅H₄CMe₂PMe₂)₂PtI₂] (26), [Rh(η-C₅Me₄CH₂PMe₂)(C₂H₄)] 29, [M(η,κP-C₅Me₄CH₂PMe₂)I₂], where M=Rh (30), or Ir, (31).     

Metallorganische lewissäuren : XX. Reaktionen von (π-C5H5)(CO)2LM-X (L = CO, PR3; M = Mo, W; X = BF4, PF6, AsF6, SbF6) mit Schwefel-haltigen liganden

The compounds (π-C₅H₅)(CO)₂LM-X (L = CO, PR₃; M = Mo, W; X = BF₄, PF₆, AsF₆, SbF₆) react with H₂S, p-MeC₆H₄SH, Ph₂S and Ph₂SO(L′) to give ionic complexes [(π-C₅H₅)(CO)₂LML′]⁺ X⁻. Also sulfur-bridged complexes, [(π-C₅H₅)(CO)₃W---SH---W(CO)₃(π-C₅H₅)]⁺ AsF₆⁻ and [(π-C₅H₅)(CO)₃M-μ-S₂C=NCH₂Ph-M(CO)₃(π-C₅H₅)], have been obtained. Reactions with SO₂ and CS₂ have been examined.     

Electrochemical reduction of the dithiophosphate complexes CpFe(CO)2[η-SP(S)(OR)2], (Cp = η-C5H5 or η-C5Me5)

The reductive electrochemistry of compounds of the type CpFe(CO)₂L (Cp = η-C₅H₅, η-C₅Me₅; L = SP(S)(OEt)₂, SP(S)(OⁱPr)₂) has been examined by polarography, cylic voltammetry and coulometry. The first one-electron reduction step leads to a bond rupture process with formation of a mercury compound, [CpFe(CO)₂]₂Hg, at a mercury electrode and the corresponding dimer species at a platinum electrode. The second reduction step corresponds to the reduction of the dimer [CpFe(CO)₂]₂, except in the polarographic reduction of pentamethylcyclopentadienyl compounds.     

First examples of η- and η --- η-coordination in triphosphorus analogues of ferrocene. Crystal structure of the iron sandwich complex [Fe(η-C5H5) (η-C2R2P3)W (CO)5] (R = Bu)

Syntheses of the novel sandwich compounds [Fe(η⁵-C₅H₅)(η⁵-C₂R₂P₃)] and [Fe(η⁵-C₅H₅)(η⁵-C₂R₂P₃)W(CO)₅], (R = Bu^t), are described. The mode of attachment of the [W(CO)₅] fragment in the latter compound has been determined by NMR and single crystal X-ray diffraction studies.     

Ein beitrag zur darstellung und reaktivität der η-allyliridium-komplexe [Ir(η-2-RC3H4) (PPr3)2]

The η³-allyliridium complexes [Ir(η³-2-RC₃H₄)(PⁱPr₃)₂] (2, 3) have been prepared in a one-pot reaction from [IrCl(C₂H₄)₂]₂, 2-RC₃H₄Li and PⁱPr₃ in 70% yield. Compounds 2 and 3 react spontaneously with H₂ to give [IrH₅(PⁱPr₃)₂] (7) and with excess PhC=CH and MeCCH to give [Ir(CCPh)₃(PⁱPr₃)₂] (5) and [Ir(CCMe)₂(CMe=CH₂)(PⁱPr₃)₂] (6), respectively. From 2 (or 3) and two equivalents of PhCCH the complex [IrH(CCPh)₂(PⁱPr₃)₂] (4) has been obtained. Treatment of 2 or 3 with CF₃CO₂H does not lead to a cleavage of the allyl-metal bond but affords the allyl(hydrido)-iridium(III) complexes [IrH(η³-2-RC₃H₄)(η¹-P₂CCF₃)(PⁱPr₃)₂] (8, 9) in almost quantitative yield.     

Synthesis and X-ray crystal structures of [Ru4H4(CO) 11(PPh3)] and [Ru4−x IrxH2−x(CO) 12(PPh3) ] (x = 0 or 1)

Three tetranuclear clusters [Ru₄H₄(CO)₁₁(PPh₃)] (1), [Ru₄H₂(CO)₁₂(PPh₃)] (2) and [Ru₃IrH(CO)₁₂(PPh₃)] (3) were formed in the reaction of [Ir(CO)Cl(PPh₃)₂] and Na[Ru₃H(CO)₁₁] in tetrahydrofuran. Complexes 1–3 were characterized by IR and ¹H and ³¹P NMR, and the structure of the clusters was confirmed by single crystal X-ray analysis. In 2 and 3 one of the carbonyls bridges between two ruthenium atoms; otherwise the compounds contain only terminal carbonyls.     

A convenient synthesis of Fe(CO)2(η-S2CNMe2)2 and Fe(η-S2CNMe2)2 from the monodentate dithiocarbamato derivative, [(η-C5H5)(CO)3W(η-SCSNMe2)] and Fe2(CO)9

A high yield synthesis of the carbonyl dithiocarbamato derivative Fe(CO)₂(η²-S₂CNMe₂)₂ and Fe(η²-S₂CNMe₂)₂ by photolysis with visible light of solutions containing Fe₂(CO)₉ or Fe₃(CO)₁₂ and [(η⁵-C₅H₅)(CO)₃W(η¹-SCSNMe₂)] is reported.     

Darstellung und Molekülstruktur des (μ-Alkylidenamido)titanocenkomplexes [(C5H5)2TiCl]2[μ-{N=C(CH2C6H5)C(CH2C6H5)=N}]

Reduction of (C₅H₅)₂TiCl₂ with Zn in presence of benzyl cyanide gives the (μ-alkyl-ideneamido)titanocene complex [(C₅H₅)₂TiCl]₂[μ-{N=C(CH₂C₆H₅)---C(CH₂C₆H₅)=N}] with C---C bond formation between two benzyl cyanide molecules.

X-ray structure investigation indicates a symmetrical structure. The C=N distances are smaller than usual, the Ti---N distances are very short, and the Ti---N---C angle differs only a little from 180°, which infers a heteroallene structure of the complex.     

Synthesis, characterization of new Rh---Co mixed-metal clusters and reactions of clusters containing [Rh2Co2C2] core with 1-alkynes and/or carbon monoxide

Six new cluster derivatives [Rh₂Co₂(CO)₆(μ-CO)₄(μ₄,η²-HCCR)] (R=FeCp₂ 1, CH₂OH 2, (CH₃O)C₁₀H₆CH(CH₃)COOCH₂CCH 3) and [RhCo₃(CO)₆(μ-CO)₄(μ₄,η²-HCCR)] (R=FeCp₂ 4, CH₂OH 5, (CH₃O)C₁₀H₆CH(CH₃)COOCH₂CCH 6) were obtained by the reactions of [Rh₂Co₂(CO)₁₂] and [RhCo₃(CO)₁₂] with substituted 1-alkyne ligands HCCR [R=FeCp₂ 7, CH₂OH 8, (CH₃O)C₁₀H₆CH(CH₃) COOCH₂CCH 9] in n-hexane at room temperature, respectively. Alkynes insert into the Co---Co bond of the tetranuclear clusters to give butterfly clusters. [Rh₂Co₂(CO)₆(μ-CO)₄(μ₄,η²-HCCFeCp₂)] (1) was characterized by a single-crystal X-ray diffraction analysis. Reactions of 1, 2 with 7, 8 and ambient pressure of carbon monoxide at 25 °C gave two known cluster complexes [Co₂(CO)₆(μ₂, η²-HCCR)] (R=FeCp₂ 10, CH₂OH 11), respectively. All clusters were characterized by element analysis, IR and ¹H-NMR spectroscopy.     

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.     

Homochiral cyclopentane-based C1-symmetric P,P ligands C5H8(PPh2)(PR2) from C2-symmetric C5H8(PCl2)2

Treatment of 1,2-trans-C₅H₈(PCl₂)₂ with 1,2-C₂H₄(NHPr-i)₂ gave the C₂-symmetric perhydro-1,6,2,5-diazaphosphocine C₅H₈{P(Cl)N(Pr-i)CH₂}₂-cyclo, which produced dissymmetric C₅H₈(PPh₂){P[N(Pr-i)CH₂]₂-cyclo} on further reaction with PhMgBr. Cleavage of the P---N bonds with gaseous HCl afforded C₅H₈(PPh₂)(PCl₂), which was converted to C₅H₈(PPh₂){P(OPh)₂}₂ by reaction with phenol. All chiral P,P derivatives were obtained as racemates as well as resolved (1R,2R)- and (1S,2S)-enantiomers.     

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.     

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.     

A novel arene bonding mode in the mixed-metal cluster Os4Ru(μ-H) 3(CO) 12(μ3-η-C6H5) P(OMe)3

The ionic coupling of [Os₄H₂(CO)₁₂]²⁻ with [Ru(η⁶-C₆H₆)(MeCN)₃]²⁺ affords the neutral mixed metal cluster Os₄Ru(μH)₂(CO)₁₂(η⁶-C₆H₆) 1. The reaction of 1 with trimethylphosphite leads to the initial formation of the addition product Os₄Ru(μH)₂(CO)₁₂(η⁶-C₆H₆)P(OMe)₃ 2, but this complex rearranges in solution to give Os₄Ru(μ-H)₃(CO)₁₂(μ₃-η⁶-C₆H₅)P(OMe)₃ 3. An X-ray structure of 3 shows that the metal core of the cluster is a ruthenium-spiked Os₄ tetrahedron, with one hydrogen atom from the arene having transferred to the Os₄ core, and one arene carbon bridging an Os-Os edge, while the ring as a whole remains η⁶-bound to the Ru atom.