Aqueous complexation studies of lead(II) and cadmium(II) with 1,3-bis(tris(hydroxymethyl)methylamino)propane pH buffer

• Type: Article in International Scientific Journal
• Date: 2014

Authors

Ferreira, CMH (Author) Other; Pinto, ISS (Author) Other; Alves, GMS (Author) Other; Sadeghi, SM (Author) Other; Helena Soares (Author) FEUP

Journal

Title: Journal of Coordination Chemistry

Vol. 67

Pages: 3354-3370

ISSN: 0095-8972

Publisher: Taylor & Francis

Indexing

ISI Web of Knowledge - 2 Citations

Scopus - 0 Citations

Scientific classification

FOS: Natural sciences

Other information

Authenticus ID: P-009-XCC

DOI: 10.1080/00958972.2014.963570

Abstract (EN): Hydrogen buffers are important in biological studies, as a steady hydrogen concentration is of great importance in most scientific studies. One of these buffers is 1,3-bis(tris(hydroxymethyl) methylamino) propane (BTP), which, considering its structure, has complexing capabilities, as previously shown for other metals. In order to know the stability constants for Cd(II) or Pb(II) with BTP, glass electrode potentiometry and direct current polarography studies were carried out. Our results show that both metals form metal complexes, with Pb(II) forming stronger complexes with BTP as evidenced by its higher stability constants. In the Pb-BTP system, five species were described; PbHL, PbL, PbL2, PbL2(OH), and PbL2(OH)(2), and their stability constants were determined to be 11.4 +/- 0.3, 4.7 +/- 0.3, 8.8 +/- 0.2, 14.4 +/- 0.3, and 18.4 +/- 0.3, respectively. For the Cd-BTP system, four complexes were detected; CdHL, CdL, CdL(OH), and CdL(OH)(2), and their stability constants were also determined as 10.9 +/- 0.4, 4.10 +/- 0.07, 8.2 +/- 0.2, and 10.9 +/- 0.2, respectively. These complexes decrease considerably the amount of free metal in solution within the buffering pH range. This fact should be considered when planning experiments were BTP and Pb(II) and/or Cd(II) ions are present.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 17