Antimony v Compounds

Liquid-vapour and liquid-solid equilibria in the SbFg-UFj and SbFg-MoFg systems have been investigated.  

AW-Dimethylcarbamoyl chloride, Me2NC(0)Q, and the iV-methyl compound both form 1 1 adducts via the oxygen atom with SbClj, but the latter slowly loses hydrogen chloride. Similar compounds result with carbamoyl azides, but in the presence of hydrogen chloride the oxygen atom is protonated and hexachloroantimonates (145) result. Structural data on SbClg, 

CaHjCOCl and the adduct with 111-CH3C8H4COCI indicate that the antimony is surrounded octahedrally by five chlorine atoms (mean Sb—Cl = 2.319) 

The I2CI+ and BrICl+ cations, which can be stabilized as the SbCl salts, result from direct combination of the appropriate halogen in the presence of 

Nojima, F. Shiba, M. Yashimura, and N. Tokura, Chem. Letters, 1972, 1133. 

Antimony(v) Compounds. The standard heat of formation of SbFj from fluorine combustion experiments is —319.5 kcal mol , and the intercalation of this compound into graphite has been discussed in two reports. The first considers the formation of Ce.sSbFj as the first product while the second reports the existence of C SbF5, where n 4, 6, or 12. A wide-line n.m.r. investigation of 

The (Sb2F,oO) ion in the rubidium salt has approximately Cj symmetry, with an SbOSb angle of 133.2(7)° and Sb—O and Sb—F distances of 1.91(2) and 1.88(2) A, respectively, while an Sb303 boat-type ring is found in the structure of Cs3(Sb3F,203). Each antimony carries four fluorines, and mean values for the important parameters are Sb—O 1.92(2) Sb—F 1.88(2) A Z.SbOSb 133.5(1.0)° /lOSbO 103.5°. 

Variable-temperature Raman data for SbCl, have been interpreted in terms of a dimer at lower temperatures, analogous to that in (SbCl40Et)2, and a normal-co-ordinate analysis has been performed. Both 1 1 and 2 1 adducts can be formed between the pentachloride and NN -dimethyloxamide, which on heating lose hydrogen chloride to give respectively (131) and (132). A series of 

Brockner, S. J. Cyvin, and H. Hovdan, Inorg. Nuclear Chem. Letters, 1975, 11, 171. R.-A. Laber and A. Schmidt, Z. anorg. Chem., 1975, 416, 32. 

Both 1 1 and 1 2 complexes are formed between dimethyl ether and antimony pentafluoride 19F n.m.r. spectra and double-resonance experiments confirm the cis structure (101) for 2SbF5,Me20.736 A minor product 

TeFJSbzFn.737 As is the case in many similar systems, there is considerable cation-anion interaction here through fluorine bridging. Detailed i.r. and Raman data for SbF5,CH3CN are in accord with C4 symmetry for the SbFsN moiety.738 

Stabilization of unusual cations by AsF7 has already been mentioned, and SbFft or Sb2Fn are often convenient alternatives. These have been successfully used in the formation of 02+SbF6 and O SbaFli,739 C102Sb2Fn,740 and I2Sb2Fn.741 Full structural data are available for the last two compounds. 

Isomer shifts in the Mossbauer spectra for SbClj,L, where L = nitrile,749 OPCl3, OPR3, DMF, Cl-,750 etc., have been interpreted to show an order of donor power for the ligands. Vibrational assignments and normal-coordinate analyses have been reported for SbCls,DMSO and SbCl5,[2H6]-DMSO.75  

Replacement of one chlorine in SbCl5 takes place on reaction with sodium ethoxide in dichloromethane, giving the known dimeric ethoxy-tetrachloride, but definite compounds were not obtained when attempts 

The 1 1 addition compound between methanol and antimony pentachloride will react with further alcohol to produce the compounds SbCls,nMeOH (n = 2— 4). I.r. data point to hydrogen-bridged structures such as (97) for the products 

van Cauteren and Th. Zeegers-Huyskens, Inorg. Nuclear Chem. Letters, 1976, 12, 323. 

Dialkyl selenites, on reaction with SbCls, readily gave the monoalkoxy-derivative SbCUOR, with SeOCla as the by-product, and the acceptor properties of such mono-alkoxy species, where R = Me, Et, C2H4C1, CH2Cp3, or CH2CCl3, have been investigated. 

A dimeric form of SbC NCO (98), stable at low temperatures, has been isolated from a reaction between KSbCl5NCO and SbCls in solution in liquid SO2, but above room temperature the rearrangement to an s-triazene derivative (99) has been confirmed by an X-ray study. A new heterocycle (100) has been synthesized by the action of water on the formamidinium salt [C1C(0)N-MeCClNMeC(0)Cl] SbCle, which is the initial product when SbCls and methyl isocyanate are refluxed in carbon tetrachloride.  

An ionic isomeric form of dimethylantimony trichloride, i.e. [Me4Sb][SbCl6], has been identified and characterized by vibrational spectroscopy as the product of alkylation of antimony pentachloride with MejInCl. Analogous reactions 

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Carbon functional groups, attachment to polysilanes, 3, 585 Carbon-heteroatom bond formation via antimony(III) compounds, 9, 428 via antimony(V) compounds, 9, 432 via bismuth(III) compounds characteristics, 9, 440 with copper catalysts, 9, 442 non-catalyzed reactions, 9, 443 with bismuth(V) compounds, 9, 450 with bismuthonium salts, 9, 449 with bismuth ylides, 9, 450 Carbon-heteroatom ligands in tetraosmium clusters, 6, 967 in tetraruthenium clusters, 6, 960... 

Antimony(V) compounds contain the antimonate ion, SbO -. Their characteristics are similar to the corresponding arsenic compounds. 

The synthesis of clathrochelates resulting from capping with antimony(V) compounds was realized for the first time as described in Ref. 74. With antimony(V) halogenides, only polymeric complexes were isolated, but antimony(V) triorganyles, unlike tin(IV) triorganyles, readily form nioximate iron(II) clathrochelates by Reaction 19. 

Antimony (v) Compounds. The antimony(v) alcoholates NaSb(OEt)6, [Sb(OEt)s]2, (SbCl40Et)2, etc., reported last year, have been characterized further by H n.m.r. 

Reaction of antimony(V) compounds with )J-diketones gives octahedral antimony derivatives of CN-6 (Equation (20)). ITiis method also works to prepare stibolanes of CN-6. Here, the products... 

Arsenic and Antimony. Three studies of reaction mechanisms for tetrahedral antimony(v) compounds are reported. These are of the reaction of trimethylantimony sulphide (MegSbS) with alkyl halides, where a four-centre transition state seems possible, the reaction of R4Sb+ cations with alkoxide ions, and the ageing of antimonic acid in aqueous solution. Both thermal and photochemical decomposition of pentaphenylanti-mony have been investigated. Whereas the products of the photochemical reaction are numerous, though all derived from phenyl radicals, the... 

Catalyst studies have promoted attention with description of the use of iron salts to prevent ether formation during ester exchange polymerization. Model compounds have been employed to elucidate the meehanisms of metal ion catalysis in both transesterification and polycondensation reactions. A differential microcalorimeter has been used to assess the relative reactivities of catalyst systems for the poly-transesterification of bis-(2-hydroxyethyl tere-phthalate) and the relationship between the viscosity of the polymerizate and the temperature of the maximum rate of heat production has been investigated. Studies on antimony(v) compounds have indicated that their activity increases during the course of 2GT synthesis. This observation has been ascribed to the reduction of the antimony(v) compounds by acetaldehyde produced by 2GT decomposition. 

The isoelectronic antimony(V) compounds show rather similar trends, when the magnitude and negative sign of SR/R are taken into account. As shown in Figure 2.4, the isomer shift becomes more negative in the series... 

Fig. 2.4. Isomer shifts of antimony(V) compounds rdative to InSb. The right-hand axis refers to the upper plot only.

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