Tetrachloroferrates

Direct Chlorination of Ethylene. Direct chlorination of ethylene is generally conducted in Hquid EDC in a bubble column reactor. Ethylene and chlorine dissolve in the Hquid phase and combine in a homogeneous catalytic reaction to form EDC. Under typical process conditions, the reaction rate is controlled by mass transfer, with absorption of ethylene as the limiting factor (77). Ferric chloride is a highly selective and efficient catalyst for this reaction, and is widely used commercially (78). Ferric chloride and sodium chloride [7647-14-5] mixtures have also been utilized for the catalyst (79), as have tetrachloroferrate compounds, eg, ammonium tetrachloroferrate [24411-12-9] NH FeCl (80). The reaction most likely proceeds through an electrophilic addition mechanism, in which the catalyst first polarizes chlorine, as shown in equation 5. The polarized chlorine molecule then acts as an electrophilic reagent to attack the double bond of ethylene, thereby faciHtating chlorine addition (eq. 6) ... 

Dichloroethane is produced by the vapor- (28) or Hquid-phase chlorination of ethylene. Most Hquid-phase processes use small amounts of ferric chloride as the catalyst. Other catalysts claimed in the patent Hterature include aluminum chloride, antimony pentachloride, and cupric chloride and an ammonium, alkaU, or alkaline-earth tetrachloroferrate (29). The chlorination is carried out at 40—50°C with 5% air or other free-radical inhibitors (30) added to prevent substitution chlorination of the product. Selectivities under these conditions are nearly stoichiometric to the desired product. The exothermic heat of reaction vapori2es the 1,2-dichloroethane product, which is purified by distillation. 

C20-0045. Write the formulas of the following complex ions (a) c/s-tetraamminechloronitrocobalt(III) (b) amminetrichloroplatinate(II) (c) /rans-diaquabis(ethylenediamine)copper(II) and (d) tetrachloroferrate(ni). 

Iron(III) complexes of 2-acetylpyridine Af-oxide iV-methyl- and 3-azabicyclo[3.2.2.]nonylthiosemicarbazone, 24 and 25, respectively, have been isolated from both iron(III) perchlorate and chloride [117], The perchlorate salt yields low spin, octahedral, monovalent, cationic complexes involving two deprotonated, tridentate thiosemicarbazone ligands coordinated via the N-oxide oxygen, azomethine nitrogen and thiol sulfur based on infrared spectral studies. Their powder ESR g-values are included in Table 1 and indicate that bonding is less covalent than for the analogous thiosemicarbazones prepared from 2-acetylpyridine, 3a and 4. Starting with iron (III) chloride, compounds with the same cations, but with tetrachloroferrate(III) anions, were isolated. 

Figure 3.78 Dependence of conductivity on the parameter R, defined by Figure 3.77(b), for ( ) poly(3,4-cyc oalkylpyrrole) perchlorates (O) poly (3,4-cycloalky I pyrrole) hexafluorophosphates (A) pol y (3.4-cy cloa IkyIthiophene) tetrachloroferrates (A) poly(J.4-cycloalkylthiophene) hexafluorophosphates all data at 24°C. From Wegner and Riihe (1989).

The tetrachloroferrate or tetralluoroborate salts of alkylated alkyl- or aryl-nitriles (nitrilium ions) are reduced to imines with triethylsilane. Subsequent hydrolysis of the intermediate imines leads to aldehydes in good yields, thus providing an excellent overall route to aldehydes from nitriles (Eq. 338).28,562... 

CER [Chlorination with Energy Recovery] A process for making 1,2-dichloroethane by reacting ethylene with chlorine in the presence of a catalyst based on the tetrachloroferrate complex. Developed by Hoechst, Germany, in 1989. See also HTC. 

Tetrachloroferrates(II) are high spin (d6-e3t23, four unpaired electrons). For example, the derivative [H-TMPP]2[FenCl4] (H-TMPP = protonated tris(2,4,6-trimethoxylphenyl)phosphine) has magnetic... 

The present procedure is an improved modification of that described by Balaban for the corresponding perchlorate. 2,4,6-Triphenylpyrylium tetrafluoroborate has also been prepared from the corresponding tetrachloroferrate with fiuoboric acid, from acetophenone and boron trifluoride, and from acetophenone, benzaldehyde, and boron trifluoride etherate. Additional methods for the preparation of pyrylium salts have been reviewed. ... 

Disodium hexabromotungstate(lV) Dipotassium pentacyanonitrosyIferrate(2 ) TrichloroseIenium(II) tetrachloroferrate(III) Tetrafluorobromate(III) ion Potassium tetraphenylborate(l-)... 

Like the propagation reaction, this probably occurs by a nucleophilic attack by the THF oxygen atom on a carbon alpha to the oxygen of the trialkyl oxonium ion salt. Commonly the triethyl-oxonium ion with a tetrafluoroborate gegenion has been used (3, 24, 32). Meerwein (3) has also used the hexachlorantimonate, tetrachloroferrate, and tetra-chloroaluminate gegenions. 

The unsubstituted 2-benzopyrylium cation 1 was first synthesized by Blount and Robinson (33JCS555) starting with indene. Its oxidation by lead tetraacetate affords homophthalic dialdehyde, which is cyclized to 2-benzopyrylium tetrachloroferrate on treatment with hydrochloric acid and ferric chloride. 

Several metal catalysts have been investigated for Michael reaction of acacH (24e) with MVK (41a) in [bmim][BF4] (bmim = butylmethylimidazolium) as solvent. Ni(acac)2 turned out to be the optimal catalyst (94% yield). With FeCl3-6H20 the yield of product 42m was limited (Scheme 8.27) [87]. It is presumed that the formation of tetrachloroferrates is a rate-limiting factor, as was observed earlier in common organic solvents or under solvent-free conditions (cf. Scheme 8.19) [88]. 

Three papers have reported on phase-transfer types of catalysis. The ionic liquid butylmethylimidazolium tetrachloroferrate catalyses the biphasic Sn reaction between primary and secondary alkyl halides with /3-hydrogens and the Grignard reagent p-FCePUMgBr.90 The yields ranged from 60 to 89%. 

The ionic liquid butylmethylimidazolium tetrachloroferrate (bmim-FeCU) has been found to be a very effective and completely air-stable catalyst for the biphasic Grignard cross-coupling with primary and secondary alkyl halides bearing /3-hydrogens.93 The ionic liquid catalyst has been successfully recycled four times. 

The following surfactants have been tested (A) Potassium benzenesulfonate in heptane (Kertes and Gutman, 1976), (B) Tri- -dodecylammonium bromide in cyclohexane (Reemik, 1965), (3) Tri-n-dodecylammonium bromide in benzene (Reemik, 1965), (D) Tri-n-dodecylammonium tetrachloroferrate in benzene (Kertes et al., 1970), (E) Most surfactants in aqueous solutions (Ward and du Reau, 1993)... 

Bis[tetraethylammonium tetrakis[benzenetellurolato] ferrate(II) was obtained from sodium benzenetellurolate and the tetrachloroferrate(II) salt as a red solid. This compound reacted with sodium hydrogen tclluridc to give a complex with an Fc/Tc/benzenctcllurolatc ratio of 1 1 l3. 

The preparation of this salt is similar in many respects to that of the tetrachloroferrate(l —) and tetrachloroaluminate(l —) salts. The molar ratios of reactants are the same. Small quantities are chosen because purification (by Soxhlet extraction) is slow. 

Pentathiazyl tetrachloroaluminate(l —) and, to a lesser extent, penta-thiazyl tetrachloroferrate(l —) are moisture-sensitive both are soluble in thionyl chloride, anhydrous formic acid, and concentrated sulfuric and nitric acids. On dissolution in acid, hydrogen chloride is evolved because of decomposition of the anion. The solution in anhydrous formic acid can be used to prepare other salts by metathesis.7 The hexachloroantimonate(l —) undergoes almost no reaction when exposed to water or moist air for 24 hr. 

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