Heteropoly acids of the Keggin type with N-substituted β-amminoethylphosphonic acids as coordinate center

Organophosphorus-heteropolytungstic acids of 1: 12 of P/W ratio, with N-substituted 2-amminoethylphosphonic acids R₂R’N⁺CH₂CH₂PO₃H⁻ (R = R’ = H; R′ = Me, R’ = H; R = R’ = Me; R = H, R ’ = Me₂CH; R′ = H, R’’ = CH₃(CH₂)₂CH₂) as coordinate centers were prepared, and characterized by means of elemental analysis, IR, UV spectroscopy, TG and DSC thermal analysis. The results indicate that these organophosphorous-HPAs possess Keggin type structure, and their stoichiometric formulation is R₂R’N⁺CH₂CH₂PO₃H⁻. W₁₂O₃₆.nH₂O. The organic side chain with the ammino-group R₂R’N⁺CH₂CH₂ ⁻ and the phosphono-group-PO₃H^- participate altogether in the formation of the primary structure of the heteropoly anion. In other words, the entirety of each compound R₂R ’N⁺CH₂CH₂PO₃H⁻ is as the core or coordinate center of the heteropoly anions. The number of crystal water in the HPA was affected obviously by the N-substituents of the organophosphonic acids.