N-butyl ferrocene

The biradical catalysts described previously for double-base propints (Ref 80) are also effective for hydrocarbon propints. Table 34 shows how p,p,-biphenylene-bis(diphenylmethyl) compares to n butyl ferrocene as a catalyst in a carboxy-terminated polybutadiene. These catalysts are claimed to overcome all of the processing difficulties, chemical stability and volatility disadvantages attributed to catalysts based on ferrocene and carborane derivatives. Another somewhat similar functioning catalyst, the free radical compd, 2,2-diphenylpicrylhydrazyl,... 

Sayles (Ref 67) combined n-butylferrocene with l-(2,3-epoxyaliphatic) carboianes of at least 3 carbonations in the aliphatic chain to function both as burning rate catalysts and cross-linking agents for carboxylated polybutadiene and acrylate binders. The use of 1,2-bis(2,3-epoxy-piopyl) carborane and 1-(2,3-epoxypropyl) car-borane boosted the burning rate of a butyl-ferrocene propint from 1.2 to 1.9 inches/sec as the data in Table 32 indicates... 

Ferrocene, like thiophene, furan, and other so-called superaromatic systems, reacts readily with mercuric acetate to form mercurated derivatives. Nes-meyanov and coworkers first reported that ferrocene could be mercurated under relatively mild conditions in either ethyl ether-alcohol or benzene-alcohol solution (63). The acetoxymercuriferrocenes formed in this manner are usually treated with an alcoholic solution of an alkali metal halide. The resulting products, chloro-mercuriferrocene (XXVII) and l,l -di(chloromercuri)ferrocene (XXVIII), can be conveniently separated by extraction with n-butyl alcohol. 

The dicyclopentadienyl metal compounds undergo Friedel-Crafts alkylation and acylation, sulfonation, metalation, arylation, and formyla-tion in the case of ferrocene, dicyclopentadienyl ruthenium, and dicyclopentadienyl osmium, whereas the others are unstable to such reactions ( ). Competition experiments (128) gave the order of electrophilic reactivity as ferrocene > ruthenocene > osmocene and the reverse for nucleophilic substitution of the first two by n-butyl lithium. A similar rate sequence applies to the acid-catalysed cleavage of the cyclopentadienyl silicon bonds in trimethylsilylferrocene and related compounds (129), a process known to occur by electrophilic substitution for aryl-silicon bonds (130). 

We studied electrochemically induced ET between a ferrocene derivative (FeCp-X) in single oil droplets and hexacyanoferrate(III) (Fe(III)) in the surrounding water phase the reaction system is schematically illustrated in Figure 11 [50,74], Tri-n-butyl phosphate (TBP) containing FeCp-X (ferrocene [X = H] or decamethylferrocene [X = DCM]), a fluorescent dye (perylene [Pe 0.5 mM] or 9,10-diphenylanthracene [DPA 10 mM]), and TBA+TPB (lOmM) is dispersed in an aqueous solution containing TBA+Cr, MgS04 (0.1 M), and potassium hexacyanoferrate(II) (Fe(II) 0.2 mM) with a 1 500 (oil/water) weight ratio as a sample emulsion. 

Desulfurization with tri(n-butyl)phosphine converts both fc(S3) (or its /er/-butyl-substituted derivatives) [273, 274] and [Fe(C5H3)2](S3)2 (or its /er/-butyl-substituted analog) [272] to polymers in which the ferrocene units are linked through disulfide bridges (cf. Sect. 5.8),... 

The directed metalation reaction—lithiation with n-butyl-lithium of a position ortho to a substituent on an aromatic ring—is described. Aromatic systems in which the reaction has been studied are benzene, thiophene, naphthalene, and ferrocene. A systematic listing of the bond types that can be formed at the site of metalation is provided. Also of interest is the assessment of the relative directing abilities of directing substituents and comments and observations on the mechanism of the reaction. Utility of the reaction is indicated by the results from asymmetric-directed lithiation and the synthesis of heterocycles. 

Carrying the concept of asymmetric lithiation one step further, Nozaki and co-workers incorporated the asymmetry-inducing complexing reagent with the metalated molecule (ferrocene) itself (37, 38). 1-Ferro-cenylmethyl-2-methylpiperidine was resolved and treated with n-butyl-lithium to give a mixture of diastereomeric lithio intermediates by directed metalation (Reaction 34). An optical yield of 93% was initially claimed for this reaction, but subsequent work by Ugi and co-workers (39) resulted in the suggestion that only a 67% optical yield was obtained. 

Cyclic voltammetric measurements were carried out with a Pine Instrument Co. Model AFRDE4 potentiostat. All electrochemical measurements were done in benzonitiile at ambient temperature at a glassy carbon working electrode, with a saturated calomel electrode or Ag/Ag (0.01 M) as a reference, and a platinum-wire counterelectrode. The electrolyte was 0.1 M tetra-n-butyl-ammonium hexafluorophosphate, and ferrocene was added as an internal reference redox system. 

Photoactive Additives.—Ferric compounds, in particular, the chloride, continue to attract much interest as photosensitizers for thermoplastics. " From e.s.r. work the mechanism appears to involve a redox reaction resulting in the formation of active hydroxy-radicals. Photodegradable polyethylene film has been developed by doping it with radiation-modified atactic polypropylene and hydroxyethyl-ferrocene. Several workers have studied the dye-sensitized photo-oxidation of polyisoprene and di-n-butyl sulphide embedded in Augustyniak and... 

Figure 2 shows a steady-state cyclic voltammogram of a 5-mM solution of ferrocene in acetonitrile at a 60-nm-radius Pt nanoelectrode [10]. The solution contains a high concentration (0.2 M) of tetra-n-butyl ammonium hexafluorophosphate, TBAPFs, and the response for this electrochemically reversible couple is under radial diffusion control. 

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