Of SbCls

Both antimony tribromide and antimony ttiiodide are prepared by reaction of the elements. Their chemistry is similar to that of SbCl in that they readily hydroly2e, form complex haUde ions, and form a wide variety of adducts with ethers, aldehydes, mercaptans, etc. They are soluble in carbon disulfide, acetone, and chloroform. There has been considerable interest in the compounds antimony bromide sulfide [14794-85-5] antimony iodide sulfide [13868-38-1] ISSb, and antimony iodide selenide [15513-79-8] with respect to their soHd-state properties, ferroelectricity, pyroelectricity, photoconduction, and dielectric polarization. 

Antimony pentafluoride may be prepared by fluorination of SbF or by treatment of SbCl with HF. In the latter method the fifth chlorine is removed with difficulty failure to remove the chlorine completely results in contamination of the distilled SbF with Sb(III) (27). 

Figure 13.10 Schcmalic representation of the pseudo-octahedral structures of (SbCls(OPCl3)j and (SbF5(OSO)j,...

Spray with a 0.03% solution of the Coomassie stain in 20% methanol Spray with a 5% solution in ethanol and heat at 100°C for 5 to 10 min Spray with a 10% solution of SbCl in chloroform heat at 110°C for 1 to 2 min... 

The acceptor number (AN) for a solvent A is determined by comparing the electron-pair accepting ability of the solvent with that of SbCls, from the oxygen atom of triethyl-... 

Fig. 14. Conductometric titrations of SbCls in nitrobenzene with different P=0-donors...

Further, the metal fluorides SbFs (with admixture of small quantities of SbCls), HgF2, and AgF are also found suitable for the fluorination of sulfenyl halides, e.g.. 

The monoxide SgO forms the 0-bonded adduct SgO SbCl5 upon treatment with antimony pentachloride in CSy adduct formation results in pyramidal inversion at the three-coordinate sulfur atom. In contrast, the treatment of 850 with antimony pentachloride induces dimerisation to give the 2 1 adduct of SbCls with the cyclic dioxide SiyOy. The chair form of the two S O constituents of this dimerisation process are evident in the conformation of the 12-membered S12 ring in the adduct. 

Tor a review of SbCL as a Friedel-Crafts catalyst, sec Yakobson Furin Synthesis 1980, 345-364. 

So the triethyloxonium cation is an effective oxidant for the production of aromatic cation radicals, but only as the hexachloroantimonate salt. The analogous (Et30 BI 4 ) or (Bu4N SbCL,) cannot be used to prepare any cation radical. This is consistent with the previously described function of SbCL, as an oxidant. The slow release of SbCl5 forms the basis for the efficacy of (Et30+SbClaromatic oxidant. Kochi s group proposed Scheme 1-107 (see below) for this slow release (Rathore and co-authors, 1998a). 

Figure 4.26. Two projections of the hexagonal structure of SbCls. The C3 axes of SbCls molecules are along cQ.

The donor number (DN) is defined as the negative AH value for the solvation of SbCls by a donating solvent in 1,2-dichloroethane solution Gutman, V. The Donor-Acceptor Approach to Molecular Interactions, Plenum Press New York, 1978, Chapter 2. 

A complex of SbCls and benzyltriethylammonium chloride, which is insensitive to air and moisture, catalyzes the Friedel-Crafts acylation of arenes with acyl chlorides and sulfonyl chlorides (Equation (36)).69 The Diels-Alder reaction of toluquinone with 1,3-dienes is catalyzed by SbCl5 with high regioselectivity (Equation (37)).70... 

Reactions of furans, dihydrofurans, tetrahydrofurans and benzo[f]furans have been reviewed <2007PHC187>. Derivatives of new furan skeletons were synthesized from bicyclic azo compounds and nitriles in the presence of SbCls or AICI3. An example is shown in Scheme 86 <2007S33>. 

The one-electron oxidation of 1,2-dithiin 20 with 1.5 equivalent of SbCls under vacuum at room temperature gave a bright yellow solution that exhibited a nine-line ESR signal. The optimized structure obtained by theoretical calculations (B3LYP/6-31G(d)) for the radical cation 20 was the one with a... 

The dissociation constants of trityl and benzhydryl salts are KD 10 4 mol/L in CH2C12 at 20° C, which corresponds to 50% dissociation at 2-10-4 mol/L total concentration of carbocationic species (cf. Table 7) [34]. The dissociation constants are several orders of magnitude higher than those in analogous anionic systems, which are typically KD 10-7 mol/L [12]. As discussed in Section IV.C.l, this may be ascribed to the large size of counterions in cationic systems (e.g., ionic radius of SbCL- = 3.0 A) compared with those in anionic systems (e.g., ionic radius of Li+ 0.68 A), and to the stronger solvation of cations versus anions. However, the dissociation constants estimated by the common ion effect in cationic polymerizations of styrene with perchlorate and triflate anions are similar to those in anionic systems (Kd 10-7 mol/L) [16,17]. This may be because styryl cations are secondary rather than tertiary ions. For example, the dissociation constants of secondary ammonium ions are 100 times smaller than those of quaternary ammonium ions [39]. 

Donor numbers vary from 2.7 for nitromethane, which is a weak EPD solvent, to 38.8 for hexamethylphosphoric triamide, a strong EPD solvent cf. Table 2-3 in Section 2.2.6. The donor number was measured directly, i.e. calorimetrically, for ca. fifty solvents [26-28, 128]. It has also been estimated by other means such as Na [29, 129], Al [130], and NMR [131] spectroscopy. Visual estimates of the varying donor numbers of EPD solvents can easily be made using the colour reactions with copper(II), nickel(II), or vanadyl(IV) complexes as acceptor solutes instead of SbCls [132]. A selection of donor numbers has already been given in Table 2-3 in Section 2.2.6. A discussion of methods for the determination of donor numbers and critical compilations of DN values for 170 and 134 solvents can be found in references [133] and [294], respectively. 

Chlorination of bis-l,2,2,2-tetrachloroethylcarbodiimide affords the perchlorinated compound, which is in the diazadiene configuration 10. Subsequent treatment of 10 with Sbp3 in the presence of a catalytic amount of SbCls gives bis-l,l-difluoro-2,2,2-trichloroethylcarbodiimide 11, bp 68 °C/0.06 Torr, mp 37 °C in 46 % yield. ... 

Antimony pentachloride, SbCh, is a liquid (mp 4°C, bp 140 °C dec ), which can be obtained by reaction of SbCls with elemental chlorine. Sohd SbCls exists in two modifications above 54.1 °C, it is trigonal bipyramidal, below this temperature, it changes reversibly into a double chlorine-bridged dimer. SbCls decomposes at 140 °C with formation of SbCls and CI2. It is a Lewis acid with a strong tendency to interact with a ligand (L) to give octahedral complexes LSbCls. Reactions with chloride ion donors lead to ionic compounds with SbCle" anions and unusual cations. Examples are shown in equations (10) and (11). 

Use of excess SbCb permits the extraction of further chlorides from the crown ether complexes. Thus reaction of [ScCl3(thf)3] in MeCN with 3mols of SbCls and dibenzo-18-crown-6 leads to the complex [ScCl(dibenzo-18-crown-6)(MeCN)] + (SbCl6 )2. If SbCb and SbCb are used together, [Sc(12-crown-4)2] + (Sb2C8)(SbCl6)2(MeCN)2 is obtained, with eight-coordinate Sc. 

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