Antimony complex, binuclear

The complex of tartaric acid and antimony (emetic) was described three centuries ago. Nevertheless, the structure of this compound has been elucidated these last fifteen years by X-ray diffraction ( 1 ). In fact, emetic presents a binuclear cyclic structure. Many authors mentioned similar complex with transition metals (vanadium (2), chromium (3)) or metalloids (arsenic (4), bismuth (5)). Emetic with phosphorus was not mentioned. Nevertheless, tartaric acid or alkyl tartrates has been utilized in phosphorus chemistry tartaric acid reacts with trialkyl phosphites giving heterocyclic phosphites (6). Starting from alkyl tartrates, we prepared spirophosphoranes with a P-H bond and sixco-ordinated compounds (7). With unprotected tartaric acid, many possibilities appear condensation as a diol, as a di(oc-hydro-xyacid), or even as a 8-hydroxyacid. 

The crystal structure of /i-oxo-bis[tris(p-chlorophenyl)(l,l,l-trifluoro-2,4-pen-tanedionato-0,0 )antimony(V)] 1/2 chloroform has been determined375. The compound crystallizes in triclinic system, space group PI. The binuclear Sb-complex consists of two distorted octahedra joined by an O atom which is situated at inversion centre the Sb-O-Sb bridge is linear. This seems to be the first example of a linear Sb-O-Sb linkage. The bridged oxygen and one of the oxygens of/3-diketone occupy trans-positions. The/3-diketonate forms two distinct Sb-0 bonds ... 

The tartrate complex of antimony(III), tartar emetic, K2[Sb2(J-C406H2)2]-3H20, has been known in medicine for over 300 years and is used for treatment of schistosomiasis and leishmaniasis the toxic side effects can be mediated by penicillamine. In the salts the ion has a binuclear structure [Fig. 10-9(b)] and the Sb atom... 

Methyl sulfonic acid reacts with antimony(V) chloride and water to yield Cl3Sb0(0H)(02S(0)CH3)SbCl3, a binuclear complex with bridging sulfonato groups. Binuclear Sb(V) complexes are also formed from SbCls and diphenylphospho-ric acid or benzylphosphonic acid alkyl ester in water. ... 

The redox properties of macrobicyclic iron(II) mono- and binuclear oximehydrazonates and a-dioximates formed by capping with antimony(V) and germanium(IV) triorganyles were studied by cyclic voltammetry [73, 74]. The electrochemical behaviour of these compounds is similar to that of analogous boron- and tin-capped clathrochelates. Oxidation of all mononuclear complexes involves a one-electron process, assigned to the oxidation of encapsulated iron(II) ion to iron(III) ion. This process is electrochemically... 

The Sb(C204)3- ion forms isolable salts and has been shown to have the i//-pentagonal-bipyramid structure (Fig. 13-1 la) with a lone pair at one axial position.66 The tartrate complexes of antimony(in) have been much studied as tartar emetic has been used medicinally for over three hundred years. This potassium salt and salts of NH4 and [Fe(phen)3]2+ are known to have a binuclear structure with tartrate bridges as shown in Fig. 13-1 lb.67... 

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