TY - JOUR
T1 - Coordination abilities of Good's buffer ionic liquids toward europium(III) ion in aqueous solution
AU - Taha, Mohamed
AU - Khan, Imran
AU - Coutinho, João A.P.
N1 - Funding Information:
This work was financed by national funding from Fundação para a Ciência e a Tecnologia (FCT, Portugal), European Union , QREN , FEDER and COMPETE for funding the CICECO (project PEst-C/CTM/LA0011/2013), QOPNA (project PEst-C/QUI/UI0062/2013) and LSRE / LCM (project PEst-C/EQB/LA0020/2013). M. Taha and I. Khan acknowledge FCT for the postdoctoral Grants SFRH/BPD/78441/2011 and SFRH/BPD/76850/2011, respectively.
Publisher Copyright:
©2015 Elsevier Ltd. All rights reserved.
PY - 2016/3/1
Y1 - 2016/3/1
N2 - Good's buffer ionic liquids (GB-ILs) are new class of ILs with self-buffering capacity at the physiological pH range for biological research. GB-ILs are formed by the combination of Good's buffers as anions and various organic bases as counter ions. In this work, the complexation of europium(III) ion with tricine and tricine-based GB-ILs, tetramethylammonium tricinate, tetraethylammonium tricinate, tetrabutylammonium tricinate, cholinium tricinate, and 1-ethyl-3-methylimidazolium tricinate in aqueous solution were determined potentiometrically at T = 298.2 K and ionic strength I = 0.1 mol dm-3 NaNO3. The protonation constants of the studied ligands (L) and their overall stability constants (lgβ) with Eu(III) were determined. The best model that fit the potentiometric data was consisted of six main species, EuL2+, EuL2+, EuL3., EuH-1.L+, EuH-2L2¯, and EuH-3L33- The lgβEu(tricine), lgβEu(tricine)2 , and lgβEu(tricine)3are 5.75, 9.51, and 12.79, respectively. The overall stability constants (lgβ) of tricine-based GB-ILs were found to be greater than those of tricine. The species distribution diagrams of these complexes were calculated and discussed in terms of percent Eu(III) and pH. We present a density functional theory (DFT) study to understand tricine chelating to Eu(III).
AB - Good's buffer ionic liquids (GB-ILs) are new class of ILs with self-buffering capacity at the physiological pH range for biological research. GB-ILs are formed by the combination of Good's buffers as anions and various organic bases as counter ions. In this work, the complexation of europium(III) ion with tricine and tricine-based GB-ILs, tetramethylammonium tricinate, tetraethylammonium tricinate, tetrabutylammonium tricinate, cholinium tricinate, and 1-ethyl-3-methylimidazolium tricinate in aqueous solution were determined potentiometrically at T = 298.2 K and ionic strength I = 0.1 mol dm-3 NaNO3. The protonation constants of the studied ligands (L) and their overall stability constants (lgβ) with Eu(III) were determined. The best model that fit the potentiometric data was consisted of six main species, EuL2+, EuL2+, EuL3., EuH-1.L+, EuH-2L2¯, and EuH-3L33- The lgβEu(tricine), lgβEu(tricine)2 , and lgβEu(tricine)3are 5.75, 9.51, and 12.79, respectively. The overall stability constants (lgβ) of tricine-based GB-ILs were found to be greater than those of tricine. The species distribution diagrams of these complexes were calculated and discussed in terms of percent Eu(III) and pH. We present a density functional theory (DFT) study to understand tricine chelating to Eu(III).
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U2 - 10.1016/j.jct.2015.11.003
DO - 10.1016/j.jct.2015.11.003
M3 - Article
AN - SCOPUS:84957871371
SN - 0021-9614
VL - 94
SP - 152
EP - 159
JO - Journal of Chemical Thermodynamics
JF - Journal of Chemical Thermodynamics
ER -