Complexation of M-(buffer)(x)-(OH)(y) systems involving divalent ions (cobalt or nickel) and zwitterionic biological buffers (AMPSO, DIPSO, TAPS and TAPSO) in aqueous solution

• Type: Article in International Scientific Journal
• Date: 2008

Authors

Carina M M Machado (Author) Other; Paula Gameiro (Author) FCUP; Helena M V M Soares (Author) FEUP

Journal

Title: Journal of Solution Chemistry

Vol. 37

Pages: 603-617

ISSN: 0095-9782

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 3 Citations

Scopus - 3 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-003-ZTC

DOI: 10.1007/s10953-008-9265-3

Abstract (EN): The complexation behavior of eight M-(buffer)(x)-(OH)(y) systems involving two divalent ions (cobalt and nickel)and four zwitterionic biological buffers (AMPSO, DIPSO, TAPS and TAPSO)were characterized. Complex formation was detected for all eight M-(buffer)(x)-(OH)(y) systems studied, but fully defined final models were obtained for only four of these systems. For systems involving cobalt or nickel with AMPSO or TAPS, a complete characterization of the systems was not possible in the studied buffer pH-range. Metal complexation was studied by glass-electrode potentiometry (GEP)and UV-Vis spectroscopy at 25.0 C and I=0.1 mol center dot dm(-3) KNO3 ionic strength. For the Ni-(L)(x)-(OH)(y) and Co-(L)(x)-(OH)(y) systems, with L = TAPSO or DIPSO, the proposed final models and overall stability constants were obtained by combining results from both techniques. For the Ni-(L)(x)-(OH)(y) systems, the measured values of the stability constants are log(10) beta(NiL)=3.0 +/- 0.1 and log(10) beta(NiL2)=4.8 +/- 0.1 for L=TAPSO, and log(10) beta(NiL)=2.7 +/- 0.1 and log(10) beta (NiL2)=4.6 +/- 0.1 for L=DIPSO. For the Co-(L)(x)-(OH)(y) systems, the overall stability constants are log(10) beta(CoL)=2.2 +/- 0.1, log(10) beta(CoL2)=3.6 +/- 0.2 and log(10) beta (CoL(OH))=7.6 +/- 0.1 for L=TAPSO, and log(10) beta(CoL)=2.0 +/- 0.1 and log(10) beta (CoL(OH))=7.8 +/- 0.1 for L=DIPSO. For both buffers, the CoL(OH)species is characterized by a major structural rearrangement.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 15