Molybdenum-Containing polysalts of the poly[ferricene-1,2(1,3:1,1′)diyl-methylene] cation

Poly(ferricene-1,2(1,3:1,1′)diyl-methylene) polycations, generated from the neutral precursor polymer 1 (M?_n=2800) by dioxygen (O₂) oxidation in sulfuric acid medium, are paired first, in a model reaction, with the hexafluorophosphate anion and, in the principal series of experiments, with the two molybdenum-containing complex anions, octamolybdate and phosphododecamolybdate. The model poly(hexafluorophosphate) 2b, as well as the polymolybdates 2c and 2d, precipitate from aqueous acidic solution of the corresponding polysulfate 2a after anion exchange; scopically. In addition to the hexafluorophosphate anion, the model polysalts 2b contain small proportions, typically 5-15%, of sulfate anion (probably present as HSO), indicating incompleteness of the anion exchange process. Analytical data suggest similarly incomplete exchange of anions also for the polymolybdates 2c and 2d. Oxidation of ferrocene units along the polymer chain is practically complete in the great majority of polysalts 2 synthesized. The molybdenum-containing polymers are of interest as plant micronutrients possessing slow-release properties.