59391-85-4

Upstream product

• 629-20-9 1,3,5,7-cyclooctatetraene 
• 11079-26-8 uranocene 
• 1871-52-9 (1Z,3Z,5Z)-Cycloocta-1,3,5-triene 

Relevant academic research and scientific papers

Thorocene adducts of the neutral 2,2′-bipyridine and its radical anion. Synthesis and crystal structures of [Th(η8-C 8H8)2(κ2-bipy)] and [Th(μ-η8:η5-C8H8) 2(κ2-bipy)K(py)2]∞

Thorocene [Th(Cot)2] (Cot = η8-C 8H8) readily reacts with 2,2′-bipyridine to give [Th(Cot)2(κ2-bipy)], which has an unusual bent geometry. This compound is rapidly reduced by KC8 into the anionic derivative [(Th(Cot)2(κ2-bipy)]-. X-ray diffraction studies suggest the latter to be a Th(IV) compound with the bipyridyl radical anion. These complexes are rare examples of bent actinocene [An(Cot)2(L)]q- (q = 0, 1; An = actinide) and bipyridine-containing thorium species.

Reactivity of Titanium(II) Arene Derivatives with Substituted Alkynes. Cyclooligomerization Reactions and Crystal and Molecular Structure of 4-C4(C6H5)4>Ti2

By treating Ti(η6-toluene)2 (X = Cl: 1a, X = Br: 1b) with C2R2 (R = Me, Ph) tetraorganylcyclobutadiene complexes of formula Ti(η4-C4R4)2 (R = Ph, X = Cl: 2a, X = Br: 2b; R = Me, X = Br: 3b) have been obtained in good yields.Compound 2b has been studied by X-ray diffraction methods.The titanium atom possesses an approximate square pyramidal coordination, the apical position being occupied by the symmetrically bonded tetraphenylcyclobutadiene ring, the four bridging bromides to the two AlBr2 groups forming the base of the pyramid, 0.99 Angstroem away from the titanium atom.The tetrabromoaluminato moiety of 2b can be substituted by carbocyclic anionic ligands, such as Cp and COT, and the corresponding complexes 4 and Ti(4h4-C4Ph4)(COT) were obtained.The spectroscopic study of the Ti(η6-benzene)2/diphenylacetylene (DPA) system (X = Cl: 5a, X = Br: 5b) has revealed the existence of three products, corresponding to the 1:1, 1:2, and 1:3 molar ratios.The possible role of the known AlX3 * C4R4 complexes in this reaction is discussed.The cyclotrimerization reactions of substituted acetylenes in the presence of η6-arene titanium(II) complexes as precursors have been studied.In toluene or methylcyclohexane Ti(η6-toluene)2 was found to catalyze the formation of alkyl-substituted aromatic hydrocarbons from 2-butyne, phenylacetylene, and 1-hexyne at about 80 deg C over 15 h with turnovers (moles of converted alkyne per mole titanium) of about 520, 900, and 990, respectively.The cyclooligomerization of DPA in the presence of Ti(η6-benzene)>(μ-X)2(AlX2)>2 (X = Cl, Br) was studied in detail.The activity of the chloro derivative 5a is higher than that of the bromide catalytic precursor 5b.In addition to hexaphenylbenzene and octaphenylcyclooctatetraene, other oligomerization by-products (triphenylethylene, 1,1,2,2-tetraphenylethane, 1,2,3-triphenylnaphthalene, and 1,2,3-triphenylazulene) were observed, whose formation was drastically reduced in the presence of alkyl aluminium halides. - Key Words: Titanium / Cyclooligomerization / Acetylenes, substituted / Tetraphenylcyclobutadiene, ligand

Heats fo Formation of Solvated Annulene and Substituted Azaannulene Dianions

It was found that the heat of solution of the potassium salt of the cyclooctatetraene (COT) dianion in tetrahydrofuran (-11.1 kcal/mol) measured calorimetrically is very different from the heat of solution determined from solubility data.This is attributed to the existence of a partially solvated solid salt (K+2COT2-*nTHF), which is the form of the COT dianion lowest in energy yet generated.This stable form of the annulene dianion is lower in energy by 393.5 kcal/mol than the gas-phase dianion with two potassium cations.Both solvation and lattice effects are rsponsible for this tremendous stabilization.Substitution of a nitrogen atom for one of the carbon atoms in the eight-member ring system results in an increase in the energy of the THF solvated dianion relative to the metal and neutral organic compound due to an increase in the electron-electron repulsion energy in the dianion.