Nonanuclear Heterometal Five-Layer Sandwich-Type Polyoxometalate.

A new nonanuclear heterometal five-layer sandwich silicotungstate [HN(CH)]HNaK{[NaMnO(OAc)][SiWO]}·34HO () has been made under hydrothermal reactions of MnCl·4HO, KMnO, trivacant [-α-SiWO] {SiW} fragment, and [HN(CH)]·Cl in NaOAc-HOAc buffer (pH = 4.8). The polyoxoanion of is a sandwich architecture, in which the nonanuclear heterometal cluster [NaMnO(OAc)] made of two triangular pyramid clusters [MnO(OAc)] {Mn} via a hexacoordinate antitrigonal prism Na linkage is encapsulated by two trivacant fragments of {SiW}. Furthermore, magnetic measurements of compound reveal the existence of antiferromagnetic exchange interactions between the metal centers.