TY - JOUR
T1 - A novel dinuclear species in the aqueous distribution of aluminum in the presence of citrate
AU - Dakanali, Maria
AU - Raptopoulou, Catherine P.
AU - Terzis, Aristidis
AU - Lakatos, Andrea
AU - Banyai, Istvan
AU - Kiss, Tamas
AU - Salifoglou, Athanasios
PY - 2003/1/27
Y1 - 2003/1/27
N2 - The chemistry of aluminum was explored in the presence of the physiological ligand citric acid and in low-pH aqueous media. As a result, the first dinuclear aluminum-citrate complex (NH4)4[Al2-(C6 H4O7)(C6H5 O7)2]·4H2O was isolated at low pH (∼3.5), and was characterized by FT-IR spectroscopy and X-ray crystallography. The structural analysis reveals the presence of a dinuclear assembly of two aluminum ions octahedrally coordinated to three citrate ligands of differing protonation state. The NMR solution behavior of this complex emphasizes its time-dependent transformation into a number of variable nature species, ultimately leading to the thermodynamically stable trinuclear species. It also establishes the participation of the dinuclear complex as a viable component of the aqueous AI(III)-citrate speciation. The chemical and structural features of this novel low molecular mass species provide considerable insight into citrate's ability, as a natural ligand, to influence the chemistry of aluminum in a pH-dependent fashion, and potentially affect aluminum's (bio)distribution, absorption, accumulation, and biotoxicity at sensitive biological sites.
AB - The chemistry of aluminum was explored in the presence of the physiological ligand citric acid and in low-pH aqueous media. As a result, the first dinuclear aluminum-citrate complex (NH4)4[Al2-(C6 H4O7)(C6H5 O7)2]·4H2O was isolated at low pH (∼3.5), and was characterized by FT-IR spectroscopy and X-ray crystallography. The structural analysis reveals the presence of a dinuclear assembly of two aluminum ions octahedrally coordinated to three citrate ligands of differing protonation state. The NMR solution behavior of this complex emphasizes its time-dependent transformation into a number of variable nature species, ultimately leading to the thermodynamically stable trinuclear species. It also establishes the participation of the dinuclear complex as a viable component of the aqueous AI(III)-citrate speciation. The chemical and structural features of this novel low molecular mass species provide considerable insight into citrate's ability, as a natural ligand, to influence the chemistry of aluminum in a pH-dependent fashion, and potentially affect aluminum's (bio)distribution, absorption, accumulation, and biotoxicity at sensitive biological sites.
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U2 - 10.1021/ic0258025
DO - 10.1021/ic0258025
M3 - Article
C2 - 12693200
AN - SCOPUS:0037467717
SN - 0020-1669
VL - 42
SP - 252
EP - 254
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 2
ER -