Preparation and structure of [Sn8W18O66](8-) - a 26-nuclear stannotungstate with a hexagonal belt of six Sn(II) ions with outward-looking lone pairs

Sn(II) acts as template in reaction with WO42- in formate buffer, inducing the formation of decanuclear [SnW9O33](10-) and further linking them by six Sn(II) centers to give orange 26-nuclear stannotungstate [Sn8W18O66](8-). Crystalline [Na-12(OH)(4)(H2O)(28)][Sn8W18O66].18H(2)O (1) was isolated and structurally characterized.