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.