ISSN:
1572-8927
Schlagwort(e):
Nitrogen-15
;
chlorine-35
;
NMR
;
cerium nitrate
;
complexation
;
water acetone mixtures
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
Notizen:
Abstract A study of the complex formation which occurs between cerium(III) and nitrate ions in aqueous solvent mixtures has been carried out by a direct, low-temperature, nitrogen-15 (15N) NMR technique. At temperatures in the range of −95 to −110°C, ligand exchange is slow enough to permit the observation of separate15N NMR signals for bulk nitrate, and this anion in the cerium(III) principal coordination shell. In water-acetone-Freon-12 mixtures, the spectra reveal the nitrato complexes do not form consecutively. Rather, signals are observed for Ce(NO3)2+, Ce(NO3) 2 1+ , and only two other higher order complexes, even at very high NO 3 − to Ce(III) mole ratios. Signal area evaluations were used to identify the possible higher order complexes. At comparable salt concentrations in aqueous-methanol mixtures, only Ce(NO3)2+ and Ce(NO3) 2 1+ are formed, reflecting a decreased tendency for complexation in media of higher dielectric constant.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00650759
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