Research output: Contribution to journal › Article › peer-review
Complexation of polyethylene glycol with Sr2+ and Ba 2+ cations in extracts containing chlorinated cobalt dicarbollide. / Stoyanov, E. S.; Smirnov, I. V.; Babain, V. A.; Antonov, N. G.; Peterman, D.; Herbst, R. S.; Todd, T. A.; Luther, T. A.
In: Radiochemistry, Vol. 46, No. 6, 01.11.2004, p. 587-592.Research output: Contribution to journal › Article › peer-review
}
TY - JOUR
T1 - Complexation of polyethylene glycol with Sr2+ and Ba 2+ cations in extracts containing chlorinated cobalt dicarbollide
AU - Stoyanov, E. S.
AU - Smirnov, I. V.
AU - Babain, V. A.
AU - Antonov, N. G.
AU - Peterman, D.
AU - Herbst, R. S.
AU - Todd, T. A.
AU - Luther, T. A.
PY - 2004/11/1
Y1 - 2004/11/1
N2 - The composition and structure of complexes that are formed in the system consisting of chlorinated cobalt dicarbollide (CCD), polyethylene glycol (PEG), and Sr2+ or Ba2+ in a polar diluent, dichloroethane or phenyl trifluoromethyl sulfone, were studied by IR and NMR spectroscopy. In extraction of Sr2+ and Ba2+ with solutions of [H 5O 2 +·PEG]CCD-, the organic phase contains the ionic associates [M2+·PEG]CCD 2 - . The Sr2+ and Ba2+ complexes have similar composition and structure: The oxygen atoms of two OH groups and six COC groups of a PEG molecule fill the first coordination sphere of the metal ions. Also, no more than two water molecules can be coordinated in the second sphere, forming hydrogen bonds with the hydrogen atoms of two OH groups of PEG. The coordination of the OH groups of PEG with the Sr2+ and Ba2+ ions is preferable over the coordination of the COC groups, as follows from the fact that the extraction of Sr2+ and Ba2+ with CCD-PEG mixtures gets worse on replacement of the OH groups of PEG by other substituents. A considerable increase in the efficiency of Sr2+ and Ba2+ extraction with H-CCD solutions in the presence of PEG is due to the fact that all the H2O molecules in the first coordination spheres of the M 2+ ions are replaced by the COC and OH groups of PEG with the formation of a hydrophobic complex [M2+·PEG](H 2O)2.
AB - The composition and structure of complexes that are formed in the system consisting of chlorinated cobalt dicarbollide (CCD), polyethylene glycol (PEG), and Sr2+ or Ba2+ in a polar diluent, dichloroethane or phenyl trifluoromethyl sulfone, were studied by IR and NMR spectroscopy. In extraction of Sr2+ and Ba2+ with solutions of [H 5O 2 +·PEG]CCD-, the organic phase contains the ionic associates [M2+·PEG]CCD 2 - . The Sr2+ and Ba2+ complexes have similar composition and structure: The oxygen atoms of two OH groups and six COC groups of a PEG molecule fill the first coordination sphere of the metal ions. Also, no more than two water molecules can be coordinated in the second sphere, forming hydrogen bonds with the hydrogen atoms of two OH groups of PEG. The coordination of the OH groups of PEG with the Sr2+ and Ba2+ ions is preferable over the coordination of the COC groups, as follows from the fact that the extraction of Sr2+ and Ba2+ with CCD-PEG mixtures gets worse on replacement of the OH groups of PEG by other substituents. A considerable increase in the efficiency of Sr2+ and Ba2+ extraction with H-CCD solutions in the presence of PEG is due to the fact that all the H2O molecules in the first coordination spheres of the M 2+ ions are replaced by the COC and OH groups of PEG with the formation of a hydrophobic complex [M2+·PEG](H 2O)2.
UR - http://www.scopus.com/inward/record.url?scp=17844409106&partnerID=8YFLogxK
U2 - 10.1007/s11137-005-0033-6
DO - 10.1007/s11137-005-0033-6
M3 - Article
AN - SCOPUS:17844409106
VL - 46
SP - 587
EP - 592
JO - Radiochemistry
JF - Radiochemistry
SN - 1066-3622
IS - 6
ER -
ID: 53580259