Antimony distibine

As a part of his classic study of reactive free radicals in the early 1930s, Paneth observed that methyl radicals react with a heated antimony mirror to produce tetramethyldistibine (22) (27). This distibine has quite remarkable properties. It forms intensely colored red crystals which melt reversibly to a yellow oil. Similarly, solutions of tetramethyldistibine are pale yellow. Although these color changes are clearly due to changes in phase rather than strictly temperature, they have been termed thermochromic... 

The five distibines (1, 22, 30, 36, and 40) that have been investigated by X-ray crystallography show very similar molecular structures (see Fig. 2 for the molecular structure of 2,2, 5,5 -tetramethylbistibole, 30). In each case the distibine adopts a staggered trans conformation so that there is an inversion center through the Sb—Sb bond. The Sb—Sb bond lengths vary between 2.84 and 2.88 A, values somewhat shorter than that of elemental antimony (2.90 A) (43). The bond angles about antimony are close to 90° and similar to those reported for other trivalent antimony compounds (44). In fact, none of the molecular parameters seems extraordinary. However, the four thermochromic distibines show unusual crystal packing (see Fig. 3, Table V) (22,25,36,40,41,45). In each case, the antimony atoms are... 

Oxygen in the enviromnent of three antimony atoms exists also in the planar oxonium salt [(Mc2Sb)30]Br, which is formed by reaction of (Mc2Sb)20 with Me2SbBr. Tetraaryldistibine oxides are formed by air oxidation of the corresponding distibines. ... 

Diarsine and distibine ligands. The n bond in ligands of the type RE = ER (E = P, As, Sb) is naturally very reactive but may be protected by a side-on coordination to a transition metal atom. The ligand is -bound with a bond order of approximately 1.5. Therefore, arsenic and antimony coordinate either via the lone-pair of electrons as a... 

The simplest representatives of this class of compounds are the antimony and bismuth analogs of tetraalkyl or tetraaryl hydrazines. Since their discovery over 80years ago [10-12], the synthesis of these compounds has been pursued in several laboratories around the world. These efforts, which have been reviewed on several occasions [3,13-18], have led to a large collection of distibines and... 

The majority of Group 9 stibide and bismuthide complexes reported to date are cobalt derivatives [113,197,198]. Calderazzo and coworkers demonstrated that Co CO)g undergoes facile insertion into distibines and dibismuthines to afford their corresponding organostibide (66) and bismuthide (67) complexes (Scheme 15.20) [199]. Based on spectral data and parallel gas volumetric experiments, it was proposed that the antimony derivative is oligomeric, whereas the bismuth derivative is... 

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