TY - JOUR
T1 - Aerial CO2 Trapped as CO32- ions in a dimeric capsule that efficiently extracts chromate, sulfate, and thiosulfate from water by anion-exchange metathesis
AU - Dutta, Ranjan
AU - Chakraborty, Sourav
AU - Bose, Purnandhu
AU - Ghosh, Pradyut
N1 - Publisher Copyright:
© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
PY - 2014/9/1
Y1 - 2014/9/1
N2 - The tris(2-aminoethyl)amine-based (tren-based) 3-cyanophenyl-substituted tripodal urea L1, one of the familiar urea-based anion receptors, has shown encapsulation of CO32- ions as the carbonate capsule [(L1)2·(CO3)·(TBA)2] (1, TBA = tetrabutylammonium) by the fixation of aerial carbon dioxide from basic dimethyl sulfoxide (DMSO) solution. Single-crystal X-ray structural analysis confirmed the encapsulation of CO32- ions in the cavity of a dimeric capsular assembly of L1 (9.62 Å) through the formation of twelve strong N-H···O hydrogen-bonding interactions. The excellent CHCl3 and CH2Cl2 solubility of 1 has been exploited for the liquid-liquid (L-L) extraction of CrO42-, SO42-, and S2O32- ions from water by anion-exchange metathesis. The extraction of these anions from water was unambiguously confirmed by 1H NMR spectroscopy, IR spectroscopy, powder XRD (PXRD), and single-crystal X-ray diffraction analysis. The 1H NMR spectroscopic analysis of the bulk extracts supports the formation of 2:1 (host-guest) complexes. For the CrO42- ion, the 53Cr NMR spectrum of the bulk extract shows a characteristic peak at δ = -99.98 ppm. The complexes of CrO42-, S2O32-, and SO42- ions with L1 (i.e., 2-4, respectively) were obtained from crystallization of the bulk extracts and show anion-assisted dimeric capsular assemblies of L1 through multiple N-H···X (X = O, S) interactions. The dimensions of the anion-encapsulated capsular assemblies are quite similar to that of the carbonate capsule and are 9.70 Å for [(L1)2·(CrO4)·(TBA)2] (2), 9.61 Å for [(L1)2·(S2O3)·(TBA)2] (3), and 9.71 Å for [(L1)2·(SO4)·(TBA)2] (4). Quantification by weighing the bulk extract shows that 1 can separately extract ca. 90% of the above three anions from water by anion-exchange metathesis. The quantitative estimations of the extractions of SO42- and CrO42- ions were further verified by gravimetric analysis by BaSO4 and BaCrO4 precipitation techniques, respectively. The extraction of SO42- ions from water was also demonstrated under alkaline conditions (pH 12.5) and in the presence of an excess of nitrate ions. Further, the quantification of CrO42- extraction was established by solution-state UV/Vis studies.
AB - The tris(2-aminoethyl)amine-based (tren-based) 3-cyanophenyl-substituted tripodal urea L1, one of the familiar urea-based anion receptors, has shown encapsulation of CO32- ions as the carbonate capsule [(L1)2·(CO3)·(TBA)2] (1, TBA = tetrabutylammonium) by the fixation of aerial carbon dioxide from basic dimethyl sulfoxide (DMSO) solution. Single-crystal X-ray structural analysis confirmed the encapsulation of CO32- ions in the cavity of a dimeric capsular assembly of L1 (9.62 Å) through the formation of twelve strong N-H···O hydrogen-bonding interactions. The excellent CHCl3 and CH2Cl2 solubility of 1 has been exploited for the liquid-liquid (L-L) extraction of CrO42-, SO42-, and S2O32- ions from water by anion-exchange metathesis. The extraction of these anions from water was unambiguously confirmed by 1H NMR spectroscopy, IR spectroscopy, powder XRD (PXRD), and single-crystal X-ray diffraction analysis. The 1H NMR spectroscopic analysis of the bulk extracts supports the formation of 2:1 (host-guest) complexes. For the CrO42- ion, the 53Cr NMR spectrum of the bulk extract shows a characteristic peak at δ = -99.98 ppm. The complexes of CrO42-, S2O32-, and SO42- ions with L1 (i.e., 2-4, respectively) were obtained from crystallization of the bulk extracts and show anion-assisted dimeric capsular assemblies of L1 through multiple N-H···X (X = O, S) interactions. The dimensions of the anion-encapsulated capsular assemblies are quite similar to that of the carbonate capsule and are 9.70 Å for [(L1)2·(CrO4)·(TBA)2] (2), 9.61 Å for [(L1)2·(S2O3)·(TBA)2] (3), and 9.71 Å for [(L1)2·(SO4)·(TBA)2] (4). Quantification by weighing the bulk extract shows that 1 can separately extract ca. 90% of the above three anions from water by anion-exchange metathesis. The quantitative estimations of the extractions of SO42- and CrO42- ions were further verified by gravimetric analysis by BaSO4 and BaCrO4 precipitation techniques, respectively. The extraction of SO42- ions from water was also demonstrated under alkaline conditions (pH 12.5) and in the presence of an excess of nitrate ions. Further, the quantification of CrO42- extraction was established by solution-state UV/Vis studies.
KW - Anions
KW - Carbon dioxide fixation
KW - Chromates
KW - Environmental chemistry
KW - Ion exchange
KW - Liquid-liquid extraction
KW - Sulfates
UR - https://www.scopus.com/pages/publications/85027928038
U2 - 10.1002/ejic.201402139
DO - 10.1002/ejic.201402139
M3 - Article
AN - SCOPUS:85027928038
SN - 1434-1948
VL - 2014
SP - 4134
EP - 4143
JO - European Journal of Inorganic Chemistry
JF - European Journal of Inorganic Chemistry
IS - 25
ER -