On the complexation of metal cations with "pure" diethylenetriamine-N, N, N′, N′′, N′′-pentakis(methylenephosphonic) acid. (2nd May 2017)

• Record Type: Journal Article
• Authors: Cardiano, Paola; Cigala, Rosalia Maria; Cordaro, Massimiliano; De Stefano, Concetta; Milea, Demetrio; Sammartano, Silvio
• Is Part Of: New journal of chemistry. Volume 41:Number 10(2017)
• Page Start: 4065
• Page End: 4075
• Publication Date: 2017-05-02
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/c7nj00118e
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : Complexation of various metal cations by DTPMA obtained by an efficient synthetic procedure has been investigated, assessing its sequestering ability and speciation in real systems. Abstract : The complex formation between a series of biologically, environmentally, and technologically relevant cations (namely Sn 2+, Zn 2+, Cu 2+, Fe 2+, Fe 3+ and Al 3+ ) and diethylenetriamine- N, N, N ′, N ′′, N ′′-pentakis(methylenephosphonic) acid (DTPMPA) has been investigated in NaCl aqueous solutions at I = 0.1 and 0.3 mol dm −3 and T = 298.15 K. The ligand used has been obtained in sufficient purity by a new efficient synthetic procedure for the determination of accurate and reliable data on its acid–base properties and metal complex formation. The stability constants determined in this work under different experimental conditions have been then used to assess the speciation of many systems containing the above-cited cations, and to quantify the sequestering ability of DTPMPA toward them, by means of the calculation of several pL0.5 values under various conditions simulating those of many real systems where this chelant is employed as a cationic sequestrant. Finally, some 1 H- and 31 P-NMR studies have also been performed to gain a further insight into the binding mode of DTPMPA toward metal cations.