Sandwich-Type Polyoxotungstate Consisting of Two Different Trilacunary Keggin-Type Units

A unique mixed W/Sb/Mn/Ag sandwich-type metal–O cluster was isolated, in which the six-membered {Ag4O3[Mn­(OH2)]2}2+ cationic belt is sandwiched between two different anionic slices: the trilacunary B-β-[SbW9O33]9– and the central-atom-lost A-α-{[Mn­(OH2)]2W7O32}18–.