Isopolyoxometalates of antimony: Arylstibonic acids [H_8(RSb) _(12)O_(28)] and derived dodecanuclear polyoxostibonates [M _2H_(10- x)(RSb)_(12)O_(30)]~(x-), M = Na or K

摘要

Electrospray ionization mass spectrometry shows arylstibonic acids, p-XC_6H_4SbO_3H_2 (X = methyl, nitro, or chloro), and 1-naphthylstibonic acid exist in MeCN as dodecanuclear aggregates [H_8(RSb)_(12)O_(28)]. With KOH or NaOH these form polyoxometalate ions [M_2H_8(RSb)_(12)O _(30)]~(2-) (M = K or Na) with a hexagonal antiprismatic array of the Sb atoms, as shown by X-ray crystallographic structures for three new examples. There is one firmly encapsulated 10-coordinate M~+ ion within an inorganic 12-crown-6 moiety {Sb_6O_6} in the hexagonal channel and one six-coordinate M~+.