1271-19-8

Basic information

• Product Name: Titanocene dichloride
• Synonyms: Bis(cyclopentadienyl)titaniuM dichloride, 97% 10GR;Bis(cyclopentadienyl)titaniuM dichloride, 97% 50GR;Bis(cyclopentadienyl)titaniuM dichloride,98% Cp2TiCl2;DICYCLOPENTADIENYLTITANIUM DICHLORIDE FO;di(cyclopenta-1,3-dien-1-yl)titaniuM(IV) chloride;Bis(cyclopentadienyl)titaniuM(IV) dichloride 97%;Cp2TiCl2;Dichlorobis(1,3-cyclopentadiene)titaniumDichlorodicyclopentadienyltitanium
• CAS NO: 1271-19-8
• Molecular Formula: C₁₀H₁₀Cl₂Ti
• Molecular Weight: 248.96
• EINECS: 215-035-9
• Product Categories: Red to red-orange crystals.;chemical intermediate;PETRO CATALYST;Industrial/Fine Chemicals;Miscellaneous;Classes of Metal Compounds;Metallocenes;Ti (Titanium) Compounds;Titanocene, etc.;Transition Metal Compounds;metallocene
• Mol File: 1271-19-8.mol
• Article Data: 98

Chemical Properties

• Melting Point: 260-280 °C (dec.)(lit.)
• Boiling Point: 355.52°C (estimate)
• Appearance: red/crystal
• Density: 1.6 g/mL at 25 °C(lit.)
• Vapor Pressure: 0.002Pa at 25℃
• Storage Temp.: Store below +30°C.
• Water Solubility: slow decomposition
• Sensitive: Air & Moisture Sensitive
• Stability: Stable. Incompatible with strong oxidizing agents. Decomposes in water. Moisture sensitive.
• Merck: 14,9482
• CAS DataBase Reference: Titanocene dichloride(CAS DataBase Reference)
• NIST Chemistry Reference: Titanocene dichloride(1271-19-8)
• EPA Substance Registry System: Titanocene dichloride(1271-19-8)

Safety Data

• Hazard Codes: Xi,T
• Statements: 37/38-61-40-34-33-36/37/38
• Safety Statements: 36-7/8-6A-45-36/37/39-26
• RIDADR: UN3261
• WGK Germany: 3
• RTECS: XR2050000
• F: 8-10-21
• TSCA: Yes
• HazardClass: 8
• PackingGroup: II
• Hazardous Substances Data: 1271-19-8(Hazardous Substances Data)

Usage

Description

Titanocene dichloride is an organotitanium compound with the chemical formula (η5-C5H5)2TiCl2, often written as Cp2TiCl2, which is a common reagent in organometallic chemistry and organic synthesis. Cp2TiCl2 does not form a "sandwich" structure like ferrocene, but a tetrahedral structure due to its four ligands around a metal center. Because of its anti-tumor activity, it has been used in clinical trials as a chemotherapeutic agent.

Chemical Properties

Titanocene dichloride is a reddish-orange crystalline solid. Moderately soluble in toluene, chloroform, alcohol, and other hydroxylic solvents; sparingly soluble in water, petroleum ether, benzene, ether, carbon disulfide, and carbon tetrachloride. Stable in dry air, slowly hydrolyzed in moist air. Titanocene dichloride is irritating to the skin and mucous membranes.

Uses

Titanocene dichloride is used as an experimental cancer chemotherapeutic agent. It is used as a research chemical, as a catalyst in Ziegler–Natta polymerization reactions, and as an implant material in orthopedics, oral surgery, and neurosurgery.This metallocene is a common reagent in organometallic and organic synthesis. Titanocene dichloride is used to prepare titanocene pentasulfide. Used as an anticancer drug.

Preparation

Cp2TiCl2 continues to be prepared similarly to its original synthesis by Wilkinson and Birmingham:2 NaC5H5 + TiCl4 → (C5H5)2TiCl2 + 2 NaClThe reaction is conducted in THF. Work-up entails extraction into chloroform/hydrogen chloride and recrystallization from toluene. In the original literature, the structure was poorly understood. Each of the two Cp rings are attached to Ti(IV) through all five carbon atoms. In organometallic chemical jargon, this bonding is referred to as η5 (see hapticity).

Production Methods

Titanocene dichloride is produced by the reaction of titanium tetrachloride with cyclopentadienyl sodium.

Reactions

Precatalyst for reduction of esters and α,β-unsaturated ketones. Catalyzes reductive deoxygenation of alcohols and hydroxylamines. Catalyst for the radical cyclization of epoxides. Reagent for the conversion of enynes to bicyclic cyclopentenones. Catalyzes silylation of alkenes and alkynes.

General Description

Titanocene dichloride appears as red to red-orange crystals. (NTP, 1992)

Air & Water Reactions

Stable in dry air. Decomposes in moist air and in water to form HCl .

Reactivity Profile

Titanocene dichloride is incompatible with strong oxidizers. Titanocene dichloride may decompose on exposure to water. .

Hazard

Toxic by inhalation, irritant to skin and mucous membranes.

Fire Hazard

Flash point data for Titanocene dichloride are not available; however, Titanocene dichloride is probably combustible.

Flammability and Explosibility

Nonflammable

Safety Profile

Poison by intravenous and intraperitoneal routes. Questionable carcinogen with experimental neoplastigenic, tumorigenic, and teratogenic data. Mutation data reported. See also TITANIUM COMPOUNDS. When heated to decomposition it emits toxic fumes of Cl-

Carcinogenicity

Based on the results of 2 year gavage studies, the National Toxicology Program determined that there was equivocal evidence of the carcinogenic activity of titanocene dichloride in male and female rats based on a marginal increase in the incidence of forestomach squamous cell effects.

Purification Methods

It forms bright red crystals from toluene or xylene/CHCl3 (1:1) and sublimes at 190o/2mm. It is moderately soluble in EtOH and insoluble in Et2O, *C6H6, CS2, CCl4, pet ether and H2O. The crystalline dipicrate explodes on melting at 139-140o. [Wilkinson et al. J Am Chem Soc 75 1011 1953, IR: Wilkinson & Birmingham J Am Chem Soc 76 4281 1954, NMR and X-ray: Glivicky & McCowan Can J Chem 51 2609 1973, Clearfield et al. J Am Chem Soc 53 1622 1975, Beilstein 16 IV 1769.]

Clinical claims and research

Titanocene dichloride, [Ti(Z5 -C5H5)2Cl2], was the first organometallic transition metal compound to be investigated clinically as an anticancer agent. It contains a cis-dichloride motif as cisplatin and was selected from several early transition metal cyclopentadienyl complexes as the best candidate for further development. The chemistry of the hard Ti(IV) ion is different from that of Pt(II): for example, cisplatin binds preferentially to the N7 of guanine in DNA, whereas titanocene dichloride exhibits higher affinity for the phosphate backbone. [Ti(Z5 -C5H5)2Cl2] hydrolyzes quickly in water, yielding a solvated Ti(IV) ion with high affinity for transferrin. As for Ga(III), selective transport of titanium ions via the transferrin route appears plausible. In vitro, titanocene dichloride is active in cisplatin-resistant cancer cells. It entered clinical trials in 1993, revealing nephrotoxicity as dose-limiting side effect. In Phase II studies as singleagent therapy no advantage over other treatment regimens was observed, and the trials were thus abandoned.

InChI:InChI=1/2C5H5.2ClH.Ti/c2*1-2-4-5-3-1;;;/h2*1-3H,4H2;2*1H;/q;;;;+2/p-2/rC10H10Ti.2ClH/c1-2-6-9(5-1)11-10-7-3-4-8-10;;/h1-5,7H,6,8H2;2*1H/q+2;;/p-2

Upstream product

• 75-09-2 dichloromethane 
• 84430-53-5 (C₅H₅)2TiCH₂SC₆H₄ 
• 7647-01-0 hydrogenchloride 
• 174577-72-1 (C₆H₃(CONH-benzyl)(S)2)Ti(cyclopentadienyl)2 
• 10025-67-9 disulfur dichloride 
• 88510-23-0 [(C₅H₅)2Ti(S₄C₆H₁₀)] 
• 7550-45-0 titanium tetrachloride 
• 75-77-4 chloro-trimethyl-silane 
• 1271-66-5 dimethyltitanocene 
• 1270-98-0 cyclopentadienyl titanium(IV) trichloride 

Downstream Products

• 1271-66-5 dimethyltitanocene 
• 74-93-1 methylthiol 
• 624-92-0 Dimethyldisulphide 
• 3561-67-9 bis(phenylthio)methane 
• 882-33-7 diphenyldisulfane 
• 1270-98-0 cyclopentadienyl titanium(IV) trichloride 
• 12701-34-7 (C₅H₅)2Ti(Cl)((CH₃)2PC₆H₅) 
• 102-54-5 ferrocene 
• 21423-86-9 9,10-dihydrofulvalene 
• 542-92-7 cyclopenta-1,3-diene 
• 127-19-5 N,N-dimethyl acetamide 
• 25583-20-4 titanium nitride 
• 1123-60-0 1,2,3,4,5-pentachloro-cyclopentane 

Relevant articles and documents

Asymmetric Carbon Dioxide Insertion into a ?-Allyltitanium(III) Complex

A ?-allyltitanium complex with a chiral cyclopentadienyl ligand reacts with carbon dioxide under mild conditions to form a carbon-carbon bond, thus providing the first demonstration of asymmetric carbon dioxide fixation.

Oxygen-Oxygen bond homolysis in a novel titanium(IV) alkylperoxide complex, Cp2Ti(OOtBu)Cl

Cp2TiCl2 reacts with NaOOtBu to form the new titanium peroxide complex, Cp2Ti(OOtBu)Cl (1), which has been characterized both in solution and in the solid state. This complex is surprisingly unreactive towards olefins and phosphines, as it does not directly transfer an oxygen atom. Instead, decomposition occurs via initial homolysis of the oxygen-oxygen bond, yielding a tert-butoxyl radical. Decomposition of 1 in the presence of phosphines yields either phosphine oxides (e.g., OPPh3) or phosphinites (e.g., tBuOPEt2), products that result from tBuO? + PR3. O-O bond homolysis is surprising because the Ti(IV) center is d0 and cannot be oxidized, where all previous clear examples of homolytic cleavage of metal peroxide complexes are facilitated by oxidation of the metal center. Copyright

Preparation of spiro-cyclic organic polysulfanes of type C6H10Sn and X-ray structural analysis of C6H10S11, a derivative of cyclo-dodecasulfur

By reaction of (C5H5)2Ti(μ-S2)2C 6H10 3 with S2Cl2 7,8,9,10,11,12-hexathiaspiro-[5.6]dodecane 4 is prepared (yield 51%) and characterized by UV, IR, Raman, mass, and NMR spectra (1H, 13C). The seven-membered CS6 ring undergoes pseudorotation in solution. With S7Cl2 the complex 3 yields 7,8,9,10,11,12,13,14,15,16,17-undecathiaspiro[5.11]heptadecane 5 (yield 23%). The yellow, monoclinic crystals of 5 consist of spirocyclic C6H10S11 molecules with the C6 ring in a chair-conformation while the CS11 ring is of the same conformation as cyclododecasulfur S12. UV, IR, Raman, mass and NMR-spectra of 5 are reported. A mixture of dichlorosulfanes SnCl2 (n = 1 - 8) reacts with 3 to give the homologous series C6H10Sm which was characterized by reversed-phase HPLC for m = 5-14. Johann Ambrosius Barth 1996.

DICYCLOPENTADIENYLTITANIUM(IV) PYRIDINE-2,6-DICARBOXYLATE COMPLEXES, SYNTHESIS AND STRUCTURAL CHARACTERIZATION AS PENTACOORDINATE TITANOCENE DERIVATIVES

Reaction of (C5H5)2Ti(CH3)2 or (CH3)4C2(C5H4)2Ti(CH3)2 with pyridine-2,6-dicarboxylic acid (dipicolinic acid) yields titanocene dipicolinate derivatives.The molecular structure of (C5H5)2Ti dipicolinate is that of an axially symmetric, pentacoordinate titanocene derivative with two carboxyl oxygen atoms and the pyridine nitrogen atom as ligating atoms.Two identical chelate bite angles of only 71 deg make the dipicolinate ligand particularly suited to form a remarkably stable titanocene derivative with unprecedented pentacoordinate geometry.

Synthesis of cationic (arene)IronCp complexes via arene exchange

Rates and regioselectivity of arene exchange reactions in cationic fused arene Fe(II)Cp complexes were investigated. Thermal exchange of pyrene, naphthalenes, and cyclooctatetraene occurs in the temperature range of 90-140°C. The most labile complex in the series studied is [(η6-(1-4,4a,8a)-1,4-dimethoxynaphthalene)FeCp][PF6] having the FeCp coordinated to the substituted ring. Pyrene and other naphthalene complexes come next, followed by the cyclooctatetraene complex. Phenanthrene, veratrol, and dihydronaphthalene do not undergo exchange at temperatures up to 130°C. With Me- and OMe-substituted naphthalenes, exchange is reversible and favors the product having the metal coordinated to the non-substituted ring. The X-ray crystal structures of the two regioisomeric 1,4-dimethoxynaphthalene complexes were determined. Arene exchange in fused arene complexes is shown to be a useful synthetic method and provides new arene complexes cleanly and efficiently. The method is particularly attractive for arenes that contain functionalities that are not compatible with the Lewis acid-mediated routes. The starting materials are readily accessible via the TiCl4-assisted Cp exchange in ferrocene.

Reduction of 1,4-dichlorobut-2-yne by titanocene to a 1,2,3-butatriene. Formation of a 1-titanacyclopent-3-yne and a 2,5-dititanabicyclo[2.2.0]hex-1(4)- ene

The 2,5-diatanabicyclo[2.2.0]hex-1(4)-ene (bis-titanocene-fi-(Z)-1,2,3- butatriene complex) (3) is formed starting from [Cp2Ti(η 2-Me3SiC2SiMe3)] by in situ generated titanocene and 1,4-dichlorobut-2-yne via the 1-titanacyclobut-3-yne (2).

ELECTROCHEMICAL STUDIES ON ORGANOMETALLIC COMPOUNDS. II. THE OXIDATION OF TITANOCENE MONOCHLORIDE

The electrochemical oxidation of titanocene monochloride, Cp2TiClL (L=tetrahydrofuran or dimethylphenylphosphine), has been studied by voltammetry on a disc electrode, by linear potential sweep voltammetry and by controlled potential electrolysis.A first one electron step yields Cp2TiClL+, which then reacts with Cp2TiClL to give Cp2TiCl2 and Cp2TiL+2.The latter is oxidized to Cp2TiL2+2

ENTHALPIES OF FORMATION OF Ti(η-C5H5)2(OR)2 COMPLEXES (R = C6H5, 2-CH3C6H4, 3-CH3C6H4, 4-CH3C6H4, AND 2-ClC6H4)

The standard enthalpies of formation of the title crystalline complexes at 298.15 K have been determined by reaction-solution calorimetry.The results give ΔHof = -379.2 +/- 8.0, ΔHfoTi(η-

REACTION OF ALKYLDERIVATIVES OF TITANIUM AND ALUMINUM WITH CARBOCATIONS

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A novel bidentate silicon containing ligand: cyclopentadienyldimethylsilane

The dimethylsilylcyclopentadienide anion undergoes cleavage of the silicon-cyclopentadienyl bond upon attempted complexation with transition metals.Complexes bearing such ligands can be obtained by metallation of the cyclopentadienyl ligand in tricarbonyl(η5-cyclopentadienyl)manganese, ferrocene and ruthenocene, followed by reaction with chlorodimethylsilane.The silicon-hydrogen function can react with carbonyl cobalt or carbonyl(hydrido)tris(triphenylphosphine)iridium, to give heterobimetallic complexes in which cyclopentadienyldimethylsilane acts as an assembling ligand.Similar complexes are obtained starting from tricarbonyl(η6-benzene)chromium.

Synthesis and Reactivity of Vinylimido Complexes of Titanocene

Tebbe's reagent (Cp2TiCH2*AlMe2Cl) or titanocene metallacyclobutanes react with nitriles in the presence of a Lewis base such as trimethylphosphine to afford vinylimido complexes of titanocene; these undergo follow-up reactions with unsaturated organic molecules to yield new heterocyclic compounds of titanocene.

Reactivity of [Cp2Ti(CO)2] and B(C6F5)3: Formation of the acylborane complexes [Cp2Ti(CO)(η2-OCB(C6 F5)3)] and [Cp2Ti(THF)(η2- OCB(C6F5)3)]

The reaction of [Cp2Ti(CO)2] with B(C6F5)3 leads, surprisingly, as revealed by X-ray structure determination to the unexpected titana acylborane [Cp2-Ti(L)(η2-OCB(C6 F5)3)] (1, L = CO, O-outside configuration; 2, L = THF, O-inside configuration) with the tris(perfluorophenyl)borane, as a Lewis acid, attached to the carbonyl carbon atom. The acylborane picture is strengthened by a theoretical calculation (ELF).

ETUDE ELECTROCHIMIQUE DE COMPOSES ORGANOMETALLIQUES XII. ACTIVATION DE LA DOUBLE LIAISON N=N DE LA BENZOCINNOLINE PAR LE MONOCHLORURE DE TITANOCENE (Cp2TiCl)2

The condensation at -30 deg C of benzocinnoline (RN=NR) on electrochemically prepared Cp2TiCl yields the titanium(IV) complex Cp2Ti(Cl)N(R)N(R)(Cl)TiCp2 which slowly decomposes into Cp2TiCl2 and benzocinnolinedicyclopentadienyltitanium.

Darstellung und Molekuelstruktur des (μ-Alkylidenamido)titanocenkomplexes 2(μ->

Reduction of (C5H5)2TiCl2 with Zn in presence of benzyl cyanide gives the (μ-alkylideneamido)titanocene complex2> 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 deg, which infers a heteroallene structure of the complex.

Electronic structure analysis and reactivity of the bimetallic bis-titanocene vinylcarboxylate complex, [(Cp2Ti)2(O2C3TMS2)]

Multimetallic redox cooperativity features heavily in both bioinorganic and synthetic reactions. Here, the electronic structure of the bimetallic Ti/Ti complex 11, [(Cp2Ti)2(O2C3TMS2)] has been revisited with EPR, confirming a predominantly TiIII/TiIII electronic structure. Reactions of 11 with 2,6-dimethylphenyl isocyanide (CNXyl), TMSCl, MeI, and BnCl were explored, revealing differential redox chemistry of the bimetallic core. In reactions with CNXyl and TMSCl, the metallacyclic TiIII center remained unperturbed, with reactions taking place at the pendent κ2(O,O)-titanocene fragment, while reaction with MeI resulted in remote oxidation of the metallacyclic Ti center, indicative of a cooperative redox process. All structures were studied via X-ray diffraction and EPR spectroscopic analysis, and their electronic structures are discussed in the context of the covalent bond classification (CBC) electron counting method.

Method for preparing titanocene dichloride

The invention discloses a method for preparing titanocene dichloride. The method comprises the following steps: cracking and rectifying dicyclopentadiene to prepare cyclopentadiene, carrying out a reflux reaction on the prepared cyclopentadiene and a mixed solution containing titanium tetrachloride, tetrahydrofuran and diethylamine, and carrying out post-treatment on the system after the reflux reaction to obtain titanocene dichloride. The post-treatment comprises the following steps: 1, cooling a post-reflux reaction system in an ice bath, filtering, and washing the obtained retentate with tetrahydrofuran and petroleum ether in sequence to obtain a washed retentate; 2, adding the washed retentate into a hydrochloric acid solution, stirring, and filtering to obtain a filtered retentate; and 3, sequentially washing the filtered retentate with ice water and ethanol, and drying to obtain titanocene dichloride. According to the method, the titanocene dichloride is prepared by adopting a cracking-reflux reaction-post-treatment method, so that the influence on the synthesis reaction due to the fusion of cyclopentadiene serving as a raw material can be avoided, and the purity of the titanocene dichloride prepared by adopting the method is 98% or above.

Mechanistic study of the titanocene(III)-catalyzed radical arylation of epoxides

An atom-economical and catalytic arylation of epoxide-derived radicals is described. The key step of the catalytic system is a sequential electron and proton transfer for the rearomatization of the radical σ-complex and catalyst regeneration. Kinetic, computational, spectroscopic, and cyclo-voltammetric investigations highlight the key issues of the reaction mechanism and catalyst stabilization by collidine hydrochloride. Studies employing radicophiles rule out the participation of cations as reactive intermediates.