Organoarsonates Enable Single-Site Condensation of Hexalacunary {PW} Polyoxotungstates.

A systematic study of the condensation reactions of arylarsonic-functionalized [α-PWO] units in acidic aqueous media identified that the specific presence of an amino group in the position of the phenyl rings induces a dimerization process that allowed isolation of discrete dimeric polyanions [(-HN-CH-AsO)PWO] () with an unprecedented polyoxometalate skeleton characterized by two seminal {PW} groups joined via a single W-O-W bridge. At the same time, addition of divalent transition metal ions (Mn, Co, and Ni) in the reaction mixture directed a condensation process on a completely different pathway resulting in one-dimensional (1D) coordination polymers based on V-shaped [{M(HO)}PWO(CHAsNO)] polyanions (M = Mn (), Co (), and Ni ()). All polyanions were isolated as hydrated mixed potassium/dimethylammonium salts and thoroughly characterized in the solid state. P NMR studies showed that the discrete cluster is comparatively stable in 1 M LiCl aqueous solution and thus represents a potential precursor for subsequent reactions.