Synthesis and spectroscopic characterization of a new tripodal hexadentate iron chelator incorporating catechol units

• Type: Article in International Scientific Journal
• Date: 2015

Authors

Carla Queiros (Author) Other; Andreia Leite (Author) Other; Ana M G Silva (Author) Other; Paula Gameiro (Author) FCUP; Baltazar de Castro (Author) FCUP; Maria Rangel (Author) ICBAS

Journal

Title: Polyhedron

Vol. 87

Pages: 1-7

ISSN: 0277-5387

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 5 Citations

Scopus - 5 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-009-ZXQ

DOI: 10.1016/j.poly.2014.10.003

Abstract (EN): We report the synthesis and physicochemical properties of a new tripodal hexadentate chelator (catTHC) synthesized by reaction of a flexible tripodal backbone with three bidentate catechol units. To improve the efficiency of the amide coupling reaction, classical conditions using two pairs of coupling reactants were tested, and a significant reduction in reaction time was achieved by using microwave irradiation with the reactants DCC/HOBt. Subsequent removal of the benzyl protecting groups using BCI3 in dichloromethane provided the final chelator in good yield. The acid-base properties of catTHC in aqueous solution and the affinity of the ligand towards iron(III) were investigated at variable pH and in the presence of iron(III) using spectroscopic methods. The hexadentate ligand forms a 1:1 complex with iron(III) whose stability constant was determined by competition with EDTA. The values obtained for the stability constant and pFe(3+) are log beta(110) = 36.70 and pFe(3+) = 26.7.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7