Indenyl compounds

A comprehensive study of 15 zirconecene monomethyl monochloro compounds and their exchange of chloride for methyl with AlMe3 indicates that the exchange process is a function of the electron deficiency at the metal.62 With low electron densities, the zirconium is more likely to exchange chloride for methyl. The study revealed low electron densities at the metal for the indenyl compounds by comparison to the cyclopentadienyl compounds. The study also revealed that steric effects are minor compared to the electronic effects of the ligands on the zirconium. 

Using an intrinsically chiral titanium compound (rac ethylene-bis-indenyl titanium dichloride, Figure 10.7), first described by Brintzinger [14], Ewen [13] obtained polypropene that was in part isotactic. Subsequently Kaminsky and Brintzinger have shown that highly isotactic polypropene can be obtained using the racemic zirconium analogue of the ethylene-bis(indenyl) compound [15],... 

X = CHgCHgNMeg) unexpectedly produced Yb bis(indenyl) compounds via homolysis of the Yb—N bond, while the Yb amides [Yb(ri5-C9H7)2 N(SiMe3)2 ] and [Yb (ri -C9H6CH2)2 N(SiMe3)2 ] were obtained with a non-fuctionalised indene.Treatment of... 

In contrast to the above, indenyl compounds such as 160, with a silyl, disilyl or trisilyl group attached to the metal atom, fail to undergo loss of a silylene on photolysis, and simply rearrange to products such as 161, as shown by the example given in equation 19. The locations of aryl groups present in the silyl side chain become scrambled during photolysis78. 

Monodentate nitrogen-donor ligands in rhodium carbonyls, 7, 124 in Ru and Os half-sandwich 7 6-arenes, 6, 518 in Ru and Os half-sandwich rf-Cp and T -indenyl compounds, 6, 475... 

Polysulfanides, in Ru and Os half-sandwich complexes, 5-Gp and 7 5-indenyl compounds, 6, 496 Polysulfide rings, with germanium, 3, 742-743 Polysulfides, in Ru and Os half-sandwich complexes, rjS-Cp and ]5-indenyl compounds, 6, 496 Polysulfido nitrosyl complexes, with chromium, 5, 303 Polytetrafluoroethylene valves, in high vacuum lines, 1, 198 Polythiaether macrocyclic ligands, in hexaruthenium carbido clusters, 6, 1018-1019... 

Polymers of a similar microstructure are obtained if unbridged substituted metallocenes having a significant rotational isomerisation barrier are used as catalyst (Fig. 16). Early attempts concentrated on substituted cyclopentadienyl and indenyl compounds [134—138],... 

Thorium(III) and uranium(III) indenyl compounds, (C9H7)3An, are also known and the molecular stmcture of U(C9H7)3 has been reported. The uranium coordination geometry is approximately trigonal, with U-C bond distances ranging from ca. 2.75(2) to 2.81(2) A. ... 

The relatively strong Bronsted acidity of cyclopentadienes, indenes, and fluorenes, permits the formation of alkali metal compounds of the conjugate bases of these organic molecules by direct reaction with the metal. The effect of substitnents on the rate of formation of 9-R-fluorenylhthium componnds in THE solution and on the degree of ion pairing in solutions of these species has been determined. Potassinm derivatives are commonly prepared by the reaction of the cyclopentadiene with potassium bis(trimethylsilyl)amide. Eluorenyl and indenyl compounds with the heavier alkah metals, Rb and Cs, are also prepared by reaction with the metal bis(trimethylsilyl)amide. The cyclopentadienyl ring in alkali metal compounds can also be coordinated to other metals. ... 

Jordan and coworkers have recently prepared several ansa-bis(indenyl) compounds (AlMe2L)indenyl 2SiMe2 and 1,2- (AlMe2L)indenyl 2C2H4 (L = THE, Et20, 1,4-dioxane) by a salt metathesis route. These were reacted with M(NMc2)4 (M = Zr, Hf) to eliminate [Me2AlNMc2]2 and form ansa-metallocene complexes of bis(dimethylamido)zirconium and bis(dimethylamido)hafmum. A simple tris(indenyl)aluminum compound has been prepared by reaction of bis(indenyl)mer-cury with aluminum metal. ... 

Figure 1.12 The structure of the anion in the complex [Nd(r -C9H7)3 ( X2-Cl)Nd(r -C9H7)3][Na(THF)6] [13]. (Adapted with permission from M.Q. Chen, G Wu, Z. Huang, et al., Studies on rare earth-indenyl compounds. 2. Synthesis and crystal structure of hexakis(tetrahydrofuran(sodium (.mu.-chloro)his(triindenylneodymate), Organometallics, 7, no. 4, 802-806, 1988. 1988 American Chemical Society.)...

Chen, M., Wu, G, Huang, Z. etal. (1988) Studies onrareearth-indenyl compounds. 2. Synthesis and crystal structure of hexakis(tetrahydrofuran)sodium (ix-chloro)bis(triindenylneodymate). Organometallics, 1 (4), 802-806. Ma, E., Yan, X., Wang, S. et al. (1981) The extraction chemistry of tanthanides with 2-ethyl-hexyle mono (2-ethyl-hexyle) phosphinate oxide. Scientia Sinica B (in Chinese), 5, 565-573. 

Imides, lattice energies of, 196 Indenyl compounds, eighth-group elements and, 73,75 Intercalation, metal chlorides, graphite and, 254-259 metal oxides, graphite and, 260-262 metal sulfides, graphite and, 260-262 Intercalation compounds, graphite, comparative survey of, 263-264... 

In the case of the thorium indenyl compound, photolysis produces Th(indenyl)3 and the alkane, the added hydrogen being derived from the indenyl ligand. This new compound of Th(III) is orange-red and soluble in hydrocarbons. 

Pseudo di- and tricoordinated crystal structures are known for Mg complexes with cyclopentadienyl and indenyl groups. The magnesocene compound CpjMg [Compound 21] has a linear Cp—Mg—Cp structure in which the Cp groups are staggered [23], The tricoordinate indenyl compounds [Compounds 22 and 23] have two different crystalline... 

Due to the fact that the polymer chain migrates during insertion, the symmetry of the metallocene is of fundamental importance to the tacticity of the polymer produced. C2-symmetric metallocenes such as the bridged bis(indenyl) compounds mentioned above have homotopic coordination sites and thereby always favor the same orientation of the prochiral monomer during the approach. This leads to the formation of an isotactic polymer (Figure 3). 

Carbon monoxide insertion into an iridium-methyl bond has been reported for an >j -indenyl compound of iridium(III), Ir(/7 -C9H7)Me2(PMe3)(CO)2- In the presence of one equivalent of trimethylamine oxide, used as a carbon monoxide scavenger, carbon monoxide insertion occurs with a simultaneous increase in the hapticity of the indenyl ligand ... 

The dichloro methylbenz[/]indenyl compound shown in Scheme 306 has been prepared by reaction of the corresponding lithium indenyl salt with TiCl3(THF)3 followed by oxidation with PbCl2.744... 

The carbon—M bonds also form by cocondensation of acidic hydrocarbons with alkaline-earth metal vapor. In this way the cyclopentadienides and indenyl compounds of Ca, Sr and Ba that are difficult to obtain by other methods for Sr and not at all for Ba can be prepared nearly quantitatively. Because of the required vacuum techniques, this method is suitable for the preparation of small amounts only. 

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