The Structure of Arylstibonic Acids

Abstract

The chemical nature of various substituted arylstibonic acids has been modified by reactions which include oxidation of tolyl groups, reduction of nitro groups, esterification, and ammonolysis. The resulting stibonic acids, which are usually contaminated with inorganic antimony compounds, can often be effectively purified by recrystallization of the corresponding pyridinium salts.Baltimore 5, Md.

Well‐Defined Stibonic and Tellurinic Acids

“…[3] Unlike their lighter Group 15 and 16 congeners, all hitherto described stibonic and tellurinic acids are ill-defined, amorphous, high-melting compounds that are poorly soluble in most organic solvents. Molecular weight determinations [4] and 121 Sb Mössbauer spectroscopic studies [5] confirm a high degree of aggregation and a trigonalbipyramidal structure for PhSb(O)(OH) 2 . By contrast, all phosphonic and arsonic acids RE(O)(OH) 2 (E = P, As), as well as sulfinic and seleninic acids RE(O)(OH) (E = S, Se), are well-defined molecular compounds with tetrahedrally coordinated central atoms E, polar (formal) E = O double bonds and E À OH groups that are usually involved in intermolecular hydrogen bonding in the solid state.…”

“…The mixture was vigorously stirred for 1 h (for 2 and 5) or 24 h (for 3 and 6) before the layers were separated. The organic layer was dried over Na 2 SO 4 …”

Arylstibonic acids [H8(RSb)12O28]; precursors to organometallic isopolyoxostibonates [Na2H9(RSb)12O30]−, (R = aryl)

“…In contrast to the arylarsonic acids, ArAsO 3 H 2 , which are well-defined molecular species with four-coordinate As, 1 arylstibonic acids have largely undetermined structures but are assumed to be oligomeric or polymeric in the solid state. 2 Mo¨ssbauer studies have been interpreted in terms of fivecoordinate Sb. 3 Very recently, an example with a very bulky aryl group has been reported as an oxygen-bridged dimer, (2,6-Mes 2 C 6 H 3 Sb) 2 O 2 (OH) 4 .…”

Assembling Homometallic Sb6 and Heterometallic Ti4Sb2 Oxo Clusters

“…Arylstibonic acids (aryl = p -isopropylphenyl, p -chlorophenyl) and tert -butylphosphonic acid were synthesized according to literature reports. Titanium isopropoxide, solvents, and common reagents were purchased from Sigma-Aldrich.…”