Sodium cyclopentadienyl compound

NaPsWwOiiii], tetradecaammonium, hentricontahydrate, 27 115 Sodium, cyclopentadienyl-, compound with l,2-dimethoxyethane(l l), 26 341 Sodium henicosaphosphide. (Na.,P.[Pg.368]

Highlights in the chemistry of cyclopentadienyl compounds have been reviewed.65 Trends in the metallation energies of the gas-phase cyclopentadienyl and methyl compounds of the alkali metals have been studied by ab initio pseudopotential calculations. Whereas there is a smooth increase in polarity of M-(C5H5) bonds from Li to Cs, lithium appears to be less electronegative than sodium in methyl derivatives. The difference between C5H5 and CH3 derivatives is attributed to differences in covalent contributions to the M-C bonds. In solution or in the solid state these trends may be masked by the effects of solvation or crystal packing.66 The interaction between the alkali metal ions Li+-K+ and benzene has also been discussed.67... 

Cyclopentadienyl compounds of lithium, sodium, potassium, magnesium and thallium are most commonly used. The synthesis of these cyclopentadienyl-transfer agents is described in more detail in Section II.B.2. Organosilicon halides and alkoxides are the most convenient substrates. The synthesis of side-chain functionalized cyclopentadienyl silanes is described in equation 541,42 as a typical example of this strategy. 

The earliest work with cyclopentadienyl was reported independently by Kaesz and by Fischer. They carried out reactions using TcCU and sodium cyclopentadienyl in the presence of BELi as a reducing agent. The species Tc(Cp)2H and [Tc(Cp)2H2]+ have been prepared. These compounds are believed to have bent metallocene (see Bent Metallocenes) stractures. The reaction of TcCLi and potassium cyclopentadienyl in THF gives the diamagnetic air-stable Tc(Cp)2Cl, whose stracture is shown in Figure 4. 

The dicyclopentadienyl derivatives of these elements which are known at the present time (those of magnesium and calcium) are in many respects similar to those of the alkali metals, being colorless, saltlike compounds. The magnesium compound was successfully prepared by the interaction of sodium cyclopentadienyl and magnesium bromide in tetra-hydrofuran 214), by thermal decomposition of cyclopentadienyl magnesium bromide 214) and, recently, by the action of cyclopentadiene... 

Sodium cyclopentadienyl reacts with indium trichloride in ether, tetrahydrofuran, or dioxan, forming the volatile compound InCsHs, which may be obtained as pale yellow needles by sublimation (56). This substance does not melt sharply, but slowly decomposes and darkens at 110°. It is very sensitive to oxidation and is slightly soluble in benzene, in which decomposition takes place it is, however, rather less soluble in ether and petroleiun ether. Water has no action on the compound, but on addition of a little sulfuric acid it is vigorously decomposed. The crystals are slightly sensitive to light. In the preparation of InCsHs an intermediate product, InlCsHsls, can be isolated in very small yield as golden crystals. On sublimation at above 160° it decomposes to form the monocyclopentadienyl compound. 

Osmocene, Os( sHo)2, has recently been made, in 20% yield, by the interaction of cyclopentadienyl sodium and osmium tetrachloride (47). It forms colorless crystals which melt at 230° again, it dissolves in organic solvents water, however, has no action on it, nor does it dissolve. The hydrogen atoms in the cyclopentadienyl rings, like those in ferrocene and ruthenocene, can undergo substitution this property has not been described for other metal cyclopentadienyl compounds, except in one... 

The THF in UCI2H2BPZ2THF could easily be replaced by pyridine, giving a dark blue compound. Treatment of a solution of the THF complex in toluene with sodium cyclopentadienyl gave a red-brown solution whose UV/vis spectrum was different from that of the U(III)cyclopentadienyl THF adduct though Still characteristic of a U(III) compound. The same reaction in THF solution, however, did yield a U/f sHslsTHF solution 290). 

Chromium forms a cyclopentadienyl compound similar to ferrocene (p. 499). Cyclopentadienyl sodium reacts with anhydrous chromium (I I) chloride in tetrahydrofuran to give red (C5H5)2Cr. By oxidising this, compounds containing the (C5H5)2Cr+ ion are easily obtained (Cotton and Wilkinson, 1954). When cyclopentadiene mixed with molybdenum or tungsten carbonyl is passed through a tube heated to 300 the dicyclopentadienyl hexacarbonyl is formed (Wilkinson, 1954) ... 

Inverted names are used only for derivatives of silanes (as Silane, dihromo- and Disilane, hexachloro-), germanes, phosphine, and the like, and as duplicate entries for metal alkyls and aryls, for example. Sodium, cyclopentadienyl-in addition to Cyclopentadienylsodium, but not for the few organic compounds. For the nomenclature of some of these and other classes of compounds, see the heading Nomenclature. 

Solutions of complex compound cyclopentadienyl-dititana in hexane and sodium cyclopentadienyl complex have high catalytic activity. Films with a metallic luster can be obtained by slowly removing the solvent from the formed gel polyacetylene in vacuum. It is assumed that the active complex has a tetrahedral structure. Polymerization mechanism is similar to the mechanism of olefin polymerization on catalyst Ziegler-Natta. Obtained at -80°C cis-polyacetylene films after doping had a conductivity of 240 (Ohm-cm" ). 

While this is the simplest method for preparing metal cyclopentadienyl compounds, it is one of the least general. It is limited to the elements Li, Na, K, Ca, and Sr and under rather vigorous conditions of temperature to Mg, In, Tl, and Fe. The reaction is usually carried out in the liquid phase at 25° to 100° C in the presence of a solvent for lithium, sodium, and potassium, or in the vapor phase at 400°- 600°C for the less reactive elements. Usually the cyclopentadienides of lithium, sodium, and potassium are not isolated but are used in solution as intermediates for the preparation of other cyclopentadienyl metal compounds. Compounds produced by reaction of cyclopentadiene vapor with metal are usually sufficiently volatile to sublime away from the reaction zone and condense in the cooler portion of the apparatus. 

Cyclopentadienyl compounds , which contains Sn NMR data, Solid-state NMR spectroscopy of microporous materials , Characterisation of porous media using NMR methods , NMR imaging of materials , which contains He and Xe NMR data, Adsorption and dynamics of sodium alkylbenzenesul-fonates on alumina , which contains H NMR data, Rubber rubber blends Part II. New developments , which contains Xe NMR data, and Infrared and NMR characterisation of the silica surface , which contains 0 and Si NMR data. ... 

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