Antimony pentachloride, 167.

Lyudvig, Rozenberg et al. (41) have also considered the kinetics of polymerization of THF initiated by antimony pentachloride. Their rate curves are clearly S-shaped (Fig. 17). This is similar to the results obtained in the triethyl aluminum system (Fig. 13) and in the PF5 case (Fig. 16). 

Lyudvig, Rozenberg et al. (41) interpreted this to mean that the rate of initiation is slow. In fact, they found that in this case the rate of initiation is so slow that even at the end of the reaction, only a small fraction of 

The experimental results are shown in Fig. 18. It is this kinetic evidence which is given to support the mechanism of initiation proposed by these workers (compare equation 15). 

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Other catalysts which may be used in the Friedel - Crafts alkylation reaction include ferric chloride, antimony pentachloride, zirconium tetrachloride, boron trifluoride, zinc chloride and hydrogen fluoride but these are generally not so effective in academic laboratories. The alkylating agents include alkyl halides, alcohols and olefines. 

The effectiveness of antimony fluoride is increased if it is used in conjunction with chlorine or with antimony pentachloride. The formation of either SbCl2F2 or a complex of SbF and SbCl probably accounts for the increased activity (4). 

Ben2enesulfonic anhydride has been claimed to be superior to ben2enesulfonyl chloride (140). Catalysts used besides aluminum chloride are ferric chloride, antimony pentachloride, aluminum bromide, and boron trifluoride (141). 

Parameter Antimony trifluoride Antimony trichloride Antimony tribromide Antimony ttiiodide Antimony pentafluoride Antimony pentachloride... 

Antimony Pentachloride. Antimony(V) chloride [7647-18-9], SbQ, is a colorless, hygroscopic, oily Hquid that is frequently yeUow because of the presence of dissolved chlorine it caimot be distilled at atmospheric pressure without decomposition, but the extrapolated normal boiling point is 176°C. In the soHd, Hquid, and gaseous states it consists of trigonal bipyramidal molecules with the apical chlorines being somewhat further away than the... 

When a diazonium salt is allowed to react with antimony pentachloride or an aryltetrachloroantimony compound, the onium salts [ArN2] [SbClg] or [ArN2] [Ar SbCl ], respectively, are formed. These can be decomposed ia an organic solvent by the addition of a powdered metal such as iron or ziac, with the formation of a diaryltrichloroantimony compound ... 

Addition Chlorination. Chlorination of olefins such as ethylene, by the addition of chlorine, is a commercially important process and can be carried out either as a catalytic vapor- or Hquid-phase process (16). The reaction is influenced by light, the walls of the reactor vessel, and inhibitors such as oxygen, and proceeds by a radical-chain mechanism. Ionic addition mechanisms can be maximized and accelerated by the use of a Lewis acid such as ferric chloride, aluminum chloride, antimony pentachloride, or cupric chloride. A typical commercial process for the preparation of 1,2-dichloroethane is the chlorination of ethylene at 40—50°C in the presence of ferric chloride (17). The introduction of 5% air to the chlorine feed prevents unwanted substitution chlorination of the 1,2-dichloroethane to generate by-product l,l,2-trichloroethane. The addition of chlorine to tetrachloroethylene using photochemical conditions has been investigated (18). This chlorination, which is strongly inhibited by oxygen, probably proceeds by a radical-chain mechanism as shown in equations 9—13. 

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. 

Antlu acite hidustries hic., 217, 218 Antlu aqumones, 17 Antibiotics S.p.A., 180 Antimony, 18 Antimony lactate, 18 Antimony pentachloride, 18 Antimony pentafluoride, 18 Antimony potassium tailrate, 18 Antimony tribromide, 18 Antimony trichloride, 18 Antimony trifluoride, 18 Antimony trioxide, 18 AntimycinA, 19 Antofagasta Pic, 206 ANTU, 19 ANWILS. A., 197 APAChic., 218... 

Once again, the addition of antimony pentachloride increases the reactivity of chlonne tnonofluoride toward alkanes but reduces its selectivity and thus allows more than one product to be generated [7d]... 

Tri- butylpyrylium can be obtained by dehydrogenating the corresponding 1,5-diketone with triphenylmethyl fluoroborate, It was shown by Farcasiu that 1,5-diketones can also he dehydrogenated and dehydrated to pyrylium salts by triphenylmethyl hexachloroantimonate generated in situ from chlorotriphenyl-methane and antimony pentachloride. Even pentaphenylpyrylium may thus be prepared at room temperature. ... 

Carbon tetrachloride is used to produce chlorofluorocarbons by the reaction with hydrogen fluoride using an antimony pentachloride (SbCls) catalyst ... 

Polychlorination processes have included exhaustive chlorination in the presence of antimony pentachloride, which destroyed the molecule (1882JCS412). Chlorine in carbon tetrachloride gave 3,4,6,8-tetrachlo-roquinoline chlorine dissolved in thionyl chloride gave the 4,5,7,8-isomer, whereas thionyl chloride alone produced a mixture of 3,4,5,6,7,8-hexachloro- (57%) and 3,4,6,8-tetrachloro- (37%) quinolines (73YZ73 74S356, 74URP432143). 

With gallium chloride, ferric chloride and antimony pentachloride the rate coefficients were dependent upon the concentration of chlorobenzene and the square of the concentration of the catalyst, but the third-order coefficients varied with the initial concentration of the catalyst (Table 103)394. The overall kinetic equation was, therefore,... 

The polymerization of 1,3,3-trimethyl-2,7-dioxabicyclo[2.2.1 Jheptane 35 was carried out in methylene chloride, toluene, and 1-nitropropane at temperatures between —78 and 0 °C32l Boron trifluoride etherate, triethyloxonium tetrafluoro-borate, antimony pentachloride, and iodine were used as initiators. Irrespective of the solvents and initiators employed, the products obtained at 0 °C were white powders with melting points of 50—55 °C, while those obtained at tower temperatures were sirups. The number average molecular weight of the unfractionated products ranged from 400 to 600. The molecular weight distribution of the oligomers prepared at 0 °C was broad, in contrast to the relatively narrow distribution of those obtained at -40 °C. 

Examples of cyclophosphazenes with ring systems containing elements other than phosphorus or nitrogen continue to be reported. The linear phosphazene [Ph2(H2N)Pi N.i P(NH2)Ph2]+Cl is cyclized by antimony pentachloride to give the compound (35). This result contrasts with... 

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