Xk. Fu et al., Heteropoly acids of the Keggin type with N-substituted beta-amminoethylphosphonic acids as coordinate center, SCI CHINA B, 44(5), 2001, pp. 524-531
Organophosphorus-heteropolytungstic acids of 1 : 12 of P/W ratio, with N-su
bstituted 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)(2)CH2) as
coordinate centers were prepared, and characterized by means of elemental a
nalysis, IR, UV spectroscopy, TG and DSC thermal analysis. The results indi
cate that these organophosphorous-HPAs possess Keggin type structure, and t
heir stoichiometric formulation is R2R'N+CH2CH2PO3H- .W12O36 . nH(2)O. The
organic side chain with the ammino-group R2R'N+CH2CH2 - and the phosphono-g
roup-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-su
bstituents of the organophosphonic acids.