[Acidites et complexes des acides (alkyl-et aminoalkyl-) phosphoniques--III Alkylphosphonates substitues de calcium(II) et cuivre(II)].
The stability constants of some phosphoric acids RPO(3)H(2) [R = CH(3), C(2)H(5), ClCH(2), Cl(2)CH, Cl(3)C, BrCH(2), Br(2)CH, BrCH(2)CH(2), ICH(2), HOCH(2), (CH(3))(3)N + CH2] and their complexes RPO(3)Ca, RPO(3)Cu, RPO(3)Cu(OH)(-) have been determined by multiparametric refinement of potentiometric titration data obtained at 25 degrees , in a 0.1M potassium nitrate medium. Linear relationships are obtained between stability and acidity constants. Formation of five-membered rings stabilize the hydroxymethylphosphonates. Conversely, cation repulsion by the permanent positive charge reduces the stabilities of complexes with trimethylammoniummethylphosphonic acid.
Wozniak
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M
Laboratoire de Physico-chimie des Solutions, Ecole Nationale Supérieure de Chimie de Lille, B.P. 40, 59650 Villeneuve d'Ascq. France.
Nowogrocki
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G