Arylstibonic Acids [h_8(rsb)_(12)o_(28)]; Precursors To Organometallic Isopolyoxostibonates [na_2h_9(rsb)_(12)o_(30)]~-, (r = Aryl)

摘要

Electrospray ionisation mass spectrometry shows that arylstibonic acids, RSbO_3H_2, give rise to oxo-bridged clusters derived from |H_8(RSb)_(13)O_(28)] which act as inorganic crown ligands towards Na~+ cations; structure determination of one derivative revealed a cage-like anion |Na_2H_9(p-O_2NC_6H_4Sb)_(12)O_(30)·4H_2O]~-.rnIn contrast to the arylarsonic acids, ArAsO_3H_2, which are well-defined molecular species with four-coordinate As, arylstibonic acids have largely undetermined structures but are assumed to be oligomeric or polymeric in the solid state. Mossbauer studies have been interpreted in terms of five-coordinate Sb. Very recently, an example with a very bulky aryl group has been reported as an oxygen-bridged dimer, (2,6-Mes_2C_6H_3Sb)_2O_2(OH)_4.