Electroanalytical characterization of Zn(II) complexes with D-mannosamine and Glycine in aqueous solutions

Vukosav, Petra; Mlakar, Marina; Selmani, Atiđa; Bregović, Nikola; Gašparović, Blaženka (2016) Electroanalytical characterization of Zn(II) complexes with D-mannosamine and Glycine in aqueous solutions. Electrochimica acta, 188 . pp. 671-678. ISSN 0013-4686

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Abstract

A detailed study of Zn(II)-D-mannosamine and mixed ligand complex Zn(II)-D-mannosamine-glycine in aqueous solution (θ = 25 ◦C, Ic = 0.55 mol L−1) was carried out by voltammetry and potentiometry, allowing their characterization. Redox process of the [ZnManN]2+ complex was registered at Ep ~ -1.01 V, [ZnGly]+ at -1.02 V, ZnGly2 at -1.18 V, while [ZnManNGly]+ at -1.12 V (pH = 8.0). Stoichiometry and stability constants of Zn (II) complexes were determined by potentiometric titrations. Calculated stability constants were found to be: log βZnManN2+ = 2.7, log βZnMaNGly+ = 7.7 and log βMaNZnGlyH-1 = -0.15. Voltammetric and potentiometric data were in good agreement, both indicating formation of two different ternary complexes, i.e. [ZnGlyManN]+ and [ZnGlyManNH-1]. Calculated speciation revealed the presence of the [ZnManN]2+ complex, as well as ternary complexes ([ZnManNGly]+) in significant amount. This study was the first attempt to quantify complexation processes of Zn (II) with naturally occurring amino sugar and mixed complex with amino acid, important for bioavailability of zinc (II) in seawater.

Item Type:	Article
Uncontrolled Keywords:	zinc; D-mannosamine; Glycine; stability constants; electrochemistry
Subjects:	NATURAL SCIENCES > Chemistry > Analytic Chemistry NATURAL SCIENCES > Interdisciplinary Natural Sciences > Marine Science
Divisions:	Division for Marine and Enviromental Research
Projects:	Project title Project leader Project code Project type Utjecaj okolišnog stresa na pojavnost i međudjelovanje biološki važnih organskih molekula i mikronutrijenata u morskom ekosustavu-AMBIOMERES Blaženka Gašparović IP-2013-11-8607 HRZZ razvoj supramolekulskih receptora kationa i aniona-SupraCAR Vladislav Tomišić IP-2014-09-7309 HRZZ
Depositing User:	Blaženka Gašparović
Date Deposited:	22 May 2018 08:43
URI:	http://fulir.irb.hr/id/eprint/4057
DOI:	10.1016/j.electacta.2015.12.054

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