Stibonium halides

Diorgano tellurium dihalides and ammonium, phosphonium, arsonium, or stibonium halides react in refluxing chloroform or ethanol to form onium diorganotetrahalo-tellurates(I V)5,1. When an onium halide with a halogen different from that in the diorgano tellurium dihalide was used, tetrahalotellurates with two different halogens in the molecule were isolated. 

The quaternary stibonium halides usually afford Sb(III) species , e.g. 

Rather than using the stibonium halide, a trialkyl- or thalkenyl dihalo antimony compoimd can be used, as in the preparation of pentavinyl antimony... 

Reactions of trimethylstibine sulfide with alkylindium halides are quite different from those with organotin compounds described above (30). As shown in the following equation, reaction of R InX with (CH3)3SbS gives stibonium salts ... 

It is, therefore, to be expected that a compound such as trimethyl-methylene stiborane, (CHs SbCtE, should be relatively unstable and attempts to synthesize this species would have to be carried out at low temperature. Another difficulty arises from the experimental fact (104) that all conventional methods of synthesis for stibonium ylides lead to pentaalkylstiboranes instead of ylides (see Introduction). Thus mcthyl-ation of (CH3)4SbX or (CHY) sHbX2 halides by organometallic reagents of lithium, magnesium, aluminum, or zinc invariably yield (CHY) 5Sb as the sole product. 

Tetraalkyl and tetraaryl compounds, R4SbX, are well-known and are often referred to as stibonium salts. There is evidence, however, that most of the tetraaryl compounds contain pentacovalent antimony. The perchlorate [(C H3)4Sb](Q04), however, is ionic (186). The tetraalkyl halides are readily prepared by quaternization of the corresponding tertiary stibines ... 

The stibonmm halides form double compounds vdth the halides of gold, mercury, bismuth and platinum. Taken on the whole the stibonium compounds are less deliquescent than the arsonium derivatives. 

Arsonium and stibonium salts have properties consistent with their ionic constitution. The hydroxides are strong alkalis like quaternary ammonium hydroxides. The tetrahedral structures of their cations have been confirmed in some instances by X-ray analysis. Of the few bismuthonium salts known, the tetraphenylborate Ph4Bi BPh4 (from Ph5Bi+Ph3B) is among the more stable. The halides readily lose halobenzene, e.g. 

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