Models of surface-confined metallocene derivatives

The silsesquioxane [((C₆H₁₁)₇Si₇O₉)(OH)₃] (LH₃) was reacted with [M(C₅H₅)₂Cl₂] (M = Ti, Zr, Hf) and with [Ti(C₅H₅)Cl₃]. The reaction with [Ti(C₅H₅)Cl₃] produced [Ti(C₅H₅)L], whereas the reaction with [Ti(C₅H₅)₂Cl₂] produced a mixture of [Ti(C₅H₅)L]_n. (n = 1, 2) as determined by NMR spectroscopy. Only [Ti(C₅H₅)L] could be isolated from the mixture. The reaction with [M(C₅H₅)₂Cl₂] (M = Zr, Hf) produced oligomeric species which contained no cyclopentadienyl ligands and which were formulated as containing trimeric [M₃L₄Cl]⁻ anions on the basis of analytical and spectroscopic data.     

Zur Wechselwirkung einiger Übergangsmetallhalogenide mit o-Mercaptophenol

The interaction of some transition metal halides with o-mercaptophenol o-Mercaptophenol reacts with WCl₆, TiCl₄, ZrCl₄, NbCl₅ and TaCl₅ giving the corresponding tris-chelat-komplexe W(C₆H₄OS)₃, H₂[M(C₆H₄OS)₃] (M = Ti, Zr), H[M(C₆H₄OS)₃] (M = Nb, Ta). (C₅H₅)₂TiCl₂ and (C₅H₅)₂ZrBr₂give in presence of triethylamine the compounds (C₅H₅)₂M(C₆H₄OS) (M = Ti, Zr). By reaction of nickel(II) acetyl-acetonate with o-mercaptophenol the polymeric octahedral complex nickel-bis-(o-hydroxy-thiophenolate) results.     

A cyclopentadienyl ring exchange method for the attachment of early transition metal metallocene dichlorides to a polymer support

PMR and mass spectral analysis have been used to study the interchange of π-bonded cyclopentadienyl rings with σ-bonded cyclopentadienyl rings in the compounds (C₅H₅)₄M (M = Ti, Zr, Hf, Nb, Ta, Mo and W) and (C₅H₅)₃V or a-bonded benzylcyclopentadienyl rings in the compounds (C₆H₅CH₂C₅H₄) (C₅H₅)₂MC1 (M = Ti, Zr, Hf, Nb, Ta, Mo and W). As soon as the Cp₄M species are generated (indicated by a color change), the interchange occurs and the equilibrium is established. As reported, no such interchange was observed in (C₅H₅) ₄Mo in the PMR time scale; however, it does occur after a longer time. By using this interchange behavior of the cyclopentadienyl ring, metallocene dichlorides of Ti, Zr, Hf, V, Nb, Ta, Mo and W have been attached to polystyrene-divinylbenzene beads.     

Spezielle Organoschwefel- und -selenverbindungen einiger Übergangsmetalle

Aluminum phenylselenolate and 1-naphthylselenolat react with TiCl₄, ZrCl₄, NbCl₅, TaCl₅, WCl₆ and CrCl₃ · 3THF giving compounds of types M(SeR)₄ (M = Ti, Zr, W; R = C₆H₅, C₁₀H₇) and M(SeR)₃ (M = Nb, Ta, Cr; R = C₆H₅, C₁₀H₇). By reaction of nickel(II), cobalt(II) and cobalt(III) acetylacetonates with thiophenol, selenophenol and 1-selenonaphthol polymeric compounds of composition Ni(XR)₂, Co(XR)_n (X = S, Se; R = C₆H₅, C₁₀H₇; n = 2 or 3) and Co(SC₆H₅)₂ · C₆H₅SH are obtained. [(n-C₄H₉)₃P]₂NiCl₂ and selenophenol in the presence of triethylamine give the monomeric compound [(n-C₄H₉)₃P]₂Ni(SeC₆H₅)₂.     

Über diphenyl- und bis(3-nitrophenyl)bleidihalogenide und über bis(3-nitrophenyl)bleihalogenokomplexe

Diaryllead dihalides R₂PbX₂ may be prepared easily by treatment of R₂Pb(OAc)₂ (OAcCH₃COO) with HX in acetic acid (R = C₆H₅; X = F, Cl, Br, I. R = 3-NO₂C₆H₄; X = Br, I). (3-NO₂C₆H₄)₂Pb(OAc)₂ forms soluble complexes when dissolved in acetic acid containing an excess of HX; (3-NO₂C₆H₄)₂PbCl₂ may be isolated from those solutions. Treatment of these solutions with CsOAc and [(C₆H₅)₄P]X, respectively, yield the complex salts M_n[(3-NO₂C₅H₄)₂PbX_2+n] (X = Cl; M = Cs, (C₆H₅)₄P; n = 0.5. X = Br; M = Cs; n = 0.5. M = (C₆H₅)₄P; n = 2, as acetic acid solvate).In addition the preparations of [(C₆H₅)₄P]_n[(3-NO₂C₆H₄)₂PbX_2+n] (X = Cl; n = 1. X = Br; n = 1, 2, as acetone solvate) and of (3-NO₂C₆H₄)₂PbF₂ (as hydrate) are described.     

Tetraalkyl titanium and zirconium metal chloride catalyst systems for ethylene polymerization

Coordination polymerization of olefins has become an industrially important, yet still poorly understood enterprise. The ethylene polymerization activity of (neophyl)_nZrCl_4-n shows a twentyfold increase from n = 4 to n = 3 and a further tenfold increase to n = 2. The heterogeneous MR₄/TiCl₄ catalysts (M = Ti, R = benzyl; M = Zr, R = benzyl, neophyl) have been developed. To explore the breadth of extendability, other metal chlorides (main group and transition metal) were substituted for TiCl₄. Indeed, excess AlCl₃ or MgCl₂ and the MR₄ compounds also produced ethylene polymerization catalysts. The inactivity of corresponding (neophyl)₄Ti systems is attributed to sterics. The abovementioned catalysts highlight the necessity of alkyl and chloride ligands at the transition metal catalyst centers.     

Complexes du titane et du zirconium contenant les ligands cyclopentadienyldiphenylphosphine et cyclopentadienylethyldiphenylphosphine: acces a des structures heterobimetalliques

Reactions of Ph₂P(CH₂)_n(C₅H₄)Li, (n = 0, 2), with MCl₄ or CpTiCl₃ (M = Ti, Zr; Cp = η⁵-C₅H₅) form Cl₂M[(η⁵-C₅H₄)(CH₂)_nPPh₂]₂ or Cl₂CpTi[(η⁵-C₅H₄)-(CH₂)₂PPh₂] in good yields. Chemical reduction with Al, or electrochemical reduction of these complexes, under CO, are described. The titanium(IV) and zirconium(IV) derivatives react with metal carbonyls (Mo(CO)₆, Cr(CO)₆, Fe(CO)₅, Mo(CO)₄(C₈H₁₂)) under formation of new heterobimetallic complexes. Reduction with Al of Cl₂CpTi[(η⁵-C₅H₄)(CH₂)₂PPh₂]Mo(CO)₅ under CO results in a new heterobimetallic species containing low valent titanium. Both complexes Cl₂M[(η⁵-C₅H₄)(CH₂)₂PPh₂]₂ (M = Ti, Zr) react with [Rh(μ-Cl)(CO)(C₂H₄)]₂ to yield {RhCl(CO)(Cl₂M[(η⁵-C₅H₄)(CH₂)₂PPh₂]₂)}x, which is assumed to be a dimer, in which the titanium or the zirconium compounds act as bridging diphosphine ligands between the rhodium atoms.     

Préparation des complexes [(C5Me4H)2MX2] (M  Ti,Zr; X  Cl,alkyl, aryl,CO). Etude par RMN dynamique de la gêne stérique à la rotation des groupements aryle liés au métal

The new ligand C₅Me₄H reacts with [TiCl₃] or [ZrCl₄] to afford the dichlor complexes [(C₅Me₄H)₂MCl₂] (M  Ti, Zr) and the trichloro complex [(C₅Me₄H)-TiCl₃]. Treatment of these complexes with RLi, or their reduction under CO, gives the derivatives [(C₅Me₄H)₁)MR₂] (R  CH₃, C₆H₅, p-C₆H₄CH₃, CO). The preparation of the new series of compounds, [(C₅Me₄H)(C₅H₅)TiR₂], is also described. The electronic effects of the C₅Me₄H ligand resemble closely those of C₅Me₅. The coalescence of the ¹H and ¹³C NMR aromatic signals indicates that rotation of the aromatic nucleus around the metal-carbon bond is restricted owing to the large size of the C₅Me₄H ligand in the aryl complexes. The activation parameters of this rotation have been determined for [(C₅Me₄H)₂Ti(p-C₆H₄CH₃)₂].     

Über die Darstellung von Tricyanmethanidometallbromiden und Organometalltricyanmethaniden durch Reaktionen mit Bromtricyanmethan BrC(CN)3

Different reactions of BrC(CN)₃ with metal bromides (MBr₄; M = Sn, Ti, Zr), metal organyles (SnR₄, MR₂ (R = C₂H₅, C₆H₅; M = Zn, Cd), C₆H₅HgBr) and with phosphorus tribromide are reported. These reactions lead to the formation of new compounds of the types MBr₃NCC(CN)₂, R₃MNCC(CN)₂, RMNCC(CN)₂ and PBr₄NCC(CN)₂, respectively. The structures of the new compounds are discussed, using results of infrared spectroscopic measurements. Mostly the pseudohalide group C(CN)₃ is bonded to the metal via the nitrogen of a cyano group. Unsolubility and IR spectra are characterizing the compounds of the types MBr₃NCC(CN)₂ and RMNCC(CN)₂ as coordination polymers. IIb-metal derivatives form pyridine complexes [RMNCC(CN)₂(C₅H₅N)₂].     

Preparation of dicyclopentadienylmetal-bis(trimethyl phosphite) complexes of titanium(II) and zirconium(II) by sodium atom reduction

The complexes (C₅H₅)₂M[P(OCH₃)₃]₂ (M = Ti and Zr) can be prepared by condensing sodium atoms at ?100°C into tetrahydrofuran solutions containing (C₅H₅)₂MCl₂ and excess trimethyl phosphite.     

Inorganic Polymers : by N.H. Ray,Academic Press,New York/San Francisco/London, 1978, 174 pages, $ 17.35.

Insertion of CO or p-TolNC into a ZrC bond of [Zr(η-C₅H₅).(R)R′] under ambient conditions in C₆H₆ leads to the stable η²-acyl- or η²-iminoacyl-complex [Zr(η-C₅H₅)₂{η²-C(X)R}R′] (X = O or NTol-p); with [Zr(η-C₅H₅)₂{CH(SiMe₃)₂}Me] as substrate there is exclusive preference for scission of the more hindered ZrC bond.     

Synthesis and characterization of heterobimetallic mixed-ligand complexes containing Zr(μ-OPri)2Al bridging units

Interesting varieties of heterobimetallic mixed-ligand complexes [Zr{M(OPrⁱ) _n }₂ (L)] (where M = Al, n = 4, L = OC₆H₄CH = NCH₂CH₂O (1); M = Nb, n = 6, L = OC₆H₄CH = NCH₂CH₂O (2); M = Al, n = 4, L = OC₁₀H₆CH = NCH₂CH₂O (3); M = Nb, n = 6, L = OC₁₀H₆CH = NCH₂CH₂O (4)), [Zr{Al(OPrⁱ)₄}₂Cl(OAr)] (where Ar = C₆H₃Me₂-2,5 (5); Ar = C₆H₂Me-4-Bu₂-2,6 (6), [Zr{Al(OPrⁱ)₄}₂(OAr)₂] (where Ar = C₆H₃Me₂-2,5 (7); Ar = C₆H₂Me-4-Bu₂-2,6 (8), [Zr{Al(OPrⁱ)₄}₃(OAr)] (where Ar = C₆H₃Me₂-2,5 (9); Ar = C₆H₃Me₂-2,6 (10), [ZrAl(OPrⁱ)_7-n (ON=CMe₂) _n ] (where n = 4 (11); n = 7 (12), [ZrAl₂(OPrⁱ)_10-n (ON=CMe₂) _n ] (where n = 4 (13); n = 6 (14); n = 10 (15) and [Zr{Al(OPrⁱ)₄}₂{ON=CMe(R)} _n Cl_2–n] [where n = 1, R = Me (16); n = 2, R = Me (17); n = 1, R = Et (18); n = 2, R = Et (19)] have been prepared either by the salt elimination method or by alkoxide-ligand exchange. All of these heterobimetallic complexes have been characterized by elemental analyses, molecular weight measurements, and spectroscopic (I.r., ¹H-, and ²⁷Al- n.m.r.) studies.     

Investigations on organotin,organolead, lead(IV), and lead(II) dithiolates

Bis(triorganometal) 1,2-dithiolates (R₃M)₂S₂R′ [(HS)₂R′ = C₇H₈S₂ for toluene-dithiol-3,4 (H₂TDT); M = Sn, Pb; R = Ph; or (HS)₂R′ = C₁₀H₁₄S₂ for 1,2-dimethyl-4,5-bis(mercaptomethyl)benzene (H₂DBB); M = Sn, R = CH₃, C₆H₅; M = Pb, R = C₆H₅], diorganometal 1,2-dithiolates R₂MS₂R′ [(HS)₂R′ = C₆H₆S₂ for 1,2-dimercaptobenzene (H₂DMB); M = Pb, R = CH₃, C₂H₅, C₆H₅; or (HS)₂R′ = H₂TDT; M = Sn, R = CH₃, C₆H₅; M = Pb, R = C₆H₅; or (HS)₂R′ = H₂DBB; M = Sn, R = CH₃, C₆H₅; M = Pb, R = CH₃, C₂H₂, C₆H₅; or (HS)₂R′ = C₈H₆N₂S₂ for 2,3-dimercaptoquinoxaline (H₂QDT); M = Pb, R = C₆H₅] and some lead(IV) and lead(II) dithiolates Pb(S₂R′)_n [(HS)₂R′ = H₂DMB, n = 2; (HS)₂R′ = H₂TDT, n = 2; (HS)₂R′ = H₂DBB, n = 1 or 2] have been prepared. Vibrational, ¹H NMR, and Mössbauer spectroscopic data are consistent with pentacoordination of tin in R₂SnTDT and with tetracoordination of tin in R₂SnS₂R′ and (R₃Sn)₂S₂R′ in the solid state. The soluble compounds are monomeric in solution. Coupling constants for the methyltin compounds indicate tetracoordination in solution.     

Reactions of alkaline earth metal or al slurries with bis-cyclopentadienyl complexes of some early transition metals

Slurries of Mg, Ca, Ba and Al, prepared by cocondensation of metal vapour with volatile organic solvents, especially toluene, at –196°C, reacted at ambient temperature with some bis-cyclopentadienyl complexes of Ti, Zr, Hf, V and Cr. [TiCl₂Cp₂] (Cp = η⁵-C₅H₅) with slurries Al in hexane or toluene, or Mg or Ba, in toluene, formed [TiClCp₂]₂ accompanied by side-products. From related reactions with slurries of Mg in tetrahydrofuran (THF), [TiCl₂Cp(THF)] was obtained and with Ca-toluene slurries an unstable paramagnetic dihydrido complex of Ti(III) was observed by using ESR spectroscopy. Reactions of [TiPh₂Cp₂ with slurries of Al or Ba in toluene yielded a form of “titanocene” (TiC₁₀H₁₀) and ESR studies of these reactions revealed related paramagnetic species in solution. Reaction of slurries of Al, Mg or Ba with [TiMe₂Cp₂] produced several different paramagnetic products which were studied by ESR spectroscopy, and the reaction of metal slurries with the complexes [MR₂Cp₂] (M = Ti, R = OPh; M = Zr or Hf, R = Cl or Me), [VRCp₂] (R = Cl or Me), and [CrCp₂] are also reported.     

Ferrocenyl derivatives of dicyclopentadienyl-titanium, -zirconium and -hafnium

Ferrocenyl compounds (C₅H₅FeC₅H₄)₂M(C₅H₅)₂ (M = Ti, Zr, Hf) were synthesized by treatment of dicyclopentadienylmetal dichloride with ferrocenyllithium. These air-sensitive, strongly coloured crystalline solids are sublimed at 120°C in vacuum (10^?2 Torr). IR, UV and PMR spectra confirm the structure of these derivatives.     

Säureinduzierte carbin-acylumwandlung

The reaction of dicarbonyl- and carbonyl(trimethylphosphine)(cyclopentadienyl)-carbyne complexes of molybdenum and tungsten η⁵-C₅H₅(CO)_2−n(PMe₃)_nMCR (n = 0, 1; M = Mo, W; R = CH₃, C₆H₅, C₆H₄CH₃, C₃H₅) with protic nucleophiles HX (X = Cl, CF₃COO, CCl₃COO) leads, through a combined protonation/carbon-carbon coupling reaction, to η²-acyl complexes η⁵-C₅H₅(CO)_1−nX₂(PMe₃)_n-M(η²-COCH₂R). The reaction conditions, the results of the spectroscopic measurements and the X-ray structure of η⁵-C₅H₅(CO)(Cl₂)W(η²-COCH₂CH₃) are reported.     

Group 12 metal complexes of tetradentate N2O2–Schiff-base ligands incorporating pyrazole: Synthesis,characterisation and reactivity toward S-donors,N-donors,copper and tin acceptors

New [M(Q)₂(X)] derivatives (where M=Zn, Cd or Hg; Q=1-phenyl-3-methyl-4-R(C=O)-pyrazolon-5-ato; in detail: Q_L, R=C₆H₅; Q_B, R=CH₂C(CH₃)₃; Q_S, R=CH(C₆H₅)₂; X=EtOH or H₂O) have been synthesised and characterised. These compounds undergo a condensation reaction with the appropriate diamine in ethanol, affording novel Schiff-base metal derivatives [M(diaquo)bis(1-phenyl-3methyl-4-R(C=N)-pyrazolone)(CH₂)_ndiimmine] (LⁿH₂, R=C₆H₅, n=2, 3 or 4; BⁿH₂, R=CH₂C(CH₃)₃, n=2, 3 or 4; SⁿH₂, R=CH(C₆H₅)₂, n=2 or 3; M=Zn, Cd or Hg). These compounds possess a six-coordinate metal environment. A ¹¹³Cd NMR study has been carried out on cadmium derivatives. The derivative [Zn(L²)(H₂O)₂] reacted with CuCl₂ and with Cu(ClO₄)₂ affording [Cu(Q_L)₂] and [Cu(en)₂](ClO₄)₂ (en=ethylendiamine), respectively, upon breaking of the C=N bond in the Schiff-base donor. In addition [Zn(L²)(H₂O)₂] reacted with 1,10-phenanthroline (phen), yielding the derivative [Zn(Q_L)₂(phen)]. Whereas when [Zn(L²)(H₂O)₂] reacted with CdCl₂, formation of [Cd(L²)(H₂O)₂] due to exchange of the metal centre was observed. Finally the derivative [Zn(L²)(Hmimt)], likely containing a five-coordinate ZnN₂O₂S central core, has been obtained from the exchange reaction between [Zn(L²)(H₂O)₂] and 1-methylimidazolin-2-thione (Hmimt).     

Synthesis,structure and ethylene polymerization of group 4 complexes with phosphinoamide ligands

Group 4 complexes containing diphosphinoamide ligands [Ph₂PNR]₂MCl₂ (3: R = ^tBu, M = Ti; 4: R = ^tBu, M = Zr; 5: R = Ph, M = Ti; 6: R = Ph, M = Zr) were prepared by the reaction of MCl₄ (M = Ti; Zr) with the corresponding lithium phosphinoamides in ether or THF. The structure of [Ph₂PN^tBu]₂TiCl₂ (3) was determined by X‐ray crystallography. The phosphinoamides functioned as η²‐coordination ligands in the solid state and the Ti? N bond length suggests it is a simple single bond. In the presence of modified methylaluminoxane or i‐Bu₃Al/Ph₃BC(C₆F₅)₄, catalytic activity of up to 59.5 kg PE/mol cat h bar was observed. Copyright © 2005 John Wiley & Sons, Ltd.     

Zur verwendung von ferricenium-kationen als selektivem oxidationsmittel in der metallorganischen chemie

The use of ferricenium cations [(C₅H₅)₂FE]X (X = BF₄, PF₆, SbF₆) as one-electron oxidizing agents for organometallic complexes is demonstrated. Sandwich compounds M(C₅H₅)₂ (M = Cr, Co, Ni) and Cr(C₆H₆)₂ are oxidized in nearly quantitative yield to the corresponding cations [M(C₅H₅)₂]BF₄ and [(C₆H₆)₂Cr]BF₄. The metalmetal bond in the dinuclear organometallic complexes [DienylM(CO)_n]₂ (M = Mo (n = 3), Fe (n = 2), Ni (n = 1)) and Co₂(CO)₈ is fissioned by (C₅H₅)₂Fe⁺ in the presence of neutral ligands L to form the corresponding cationic compounds [DienylM(CO)_nL_m]X (M = Mo (n = 2), Fe (n = 2), Ni (n = 0)) and [Co(CO)₃L₂BF₄ (L = VB and VIB donor ligands) in high yields.The practical applications of ferricenium cations are discussed in comparison with other methods for the preparation of cationic organometallic complexes.