Potassium Separation from S-Block and Other Elements Using a Polymeric Crown Ether

Abstract

A very simple column chromatographic separation method has been developed for potassium. The separation of potassium was carried out using poly(dibenz0-18-crown-6) with hydrobromic acid medium. Large amounts of sodium and rubidium were separated from trace level potassium. Potassium was separated from a number of associated elements in tertiary and four-component systems. The proposed method was extended to the analysis of potassium in various rocks and biological and medicinal samples. The method is very simple, rapid, selective, and reproducible. The reproducibility of the method is f2%.Crown compounds are applied in liquid chromatography. However, relatively little information is available1-5 concerning the use of crown ethers, crown ether-modified silicas, and polymeric crown ethers for column chromatographic separation of potassium from other elements. One area of thecation separations field in which almost all present systems have difficulty is that of separations from acidic matrices. Polymeric crown ethers provide the means for selective cation separations from acidic matrices because they possess special features such as high resistance to chemicals, to temperature, and also to polar solvents such as acetone, alcohols, etc. Taking advantage of these attractive properties of poly(dibenz0-18-crown-6) (P(dbl8c6)), we have reported column chromatographic separation studies of molybdenum(VI),6 uranium-(VI),7 and lead8 from hydrochloric acid medium. This paper describes in detail the separation of potassium from a number of other elements using poly(dibenz0-18-crown-6) in hydrobromic acid medium. EXPERIMENTAL SECTIONInstrumentation, Column Material, and Reagents. The instruments and chemicals used were similar to those reportedProcedure. An aqueous sample solution containing 100 pg of potassium was mixed with HBr to get a concentration (1) Fernando, L. A.; Miles, M. L.; Bowen, L. H. Radiochem. Radionanal. Lerr. 1919, 38, 387-394. (2) Nakajima, M.; Kimura, K.; Hayata, E.; Shono, T. J. Liq. Chromarogr. 1984, 7,2115-2125. (3) Kimure, K.; Nakajima, M.; Shono, T. J. Polym. Sci. Polym. Chem. Ed. 1985, (4) Yagi, K.; Sanchez, M. C. Makromol. Chem. Rapid Commun. 1981,2,311-( 5 ) Igawe, M.; Ito, I.; Tanaka, M. Bunseki Kagaku 1980.29, 58G584; Chem. (6) Mohite, B . S.; Patil, J. M.; Zambare, D. N. Talanra 1993, 40, 1511-1518.(7) Mohite, B. S.; Patil, J. M.; Zambare, D. N.; Mali, U. G . Bull. Chem. Soc. (8) Mohite, B. S.; Patil, J. M.; Zambare, D. N. J. Indian Chem. SOC. 1994, 71, (9) Mohite, B. S.; Khopkar, S . M. Indian J. Chem. 1983, 2 2 4 962-964.of 0.5-8.0 M in a total volume of 10 mL. The solution was passed through a P(db18c6) column, preconditioned with HBr of the same acidity as that of the sample solution, at a flow rate of 0.5 mL/min. The column was then washed with HBr of the same acidity to remove unadsorbed cations. The adsorbed potassium was eluted with different eluting agents (described latter) at a flow rate of 0.5 mL/min. Fractions of 5 mL each were collected, and, after evaporation, the effluent residue...

Preparation, characterization and crystal structures of copper(II) hexaazamacrotetracyclic complexes with organic ligands

“…230243 for (1) and 230244 for (2). Copies of this information may be obtained free of charge from the Director, CCDC, 12 Union Road, Cambridge, CB2,1EZ, UK (fax: +44-1223-336033; email: deposit@ccdc.cam.uk or http://www.ccdc.cam.ac.…”

“…The first-row transition metal(II) complexes with polyaza macrocyclic ligands have attracted considerable interest due to their importance as metal ion-selective reagents [1][2][3] and models for metalloenzyme active sites [4][5][6]. It has been widely observed that the structures and chemical properties of metal complexes with these ligands are influenced by several factors, including the metal ion size, anionic groups and ligand topology, such as the cavity size, type and number of donor atoms, and stereochemical rigidity [7][8][9][10][11][12][13][14][15][16][17].…”

Template-directed synthesis of macrocyclic copper(II) complexes of diazacyclam, 1,3,6,10,12,15-hexaazatricyclo[13.3.1.16,10]eicosane

“…Syntheses of macrocycles were sometimes limited due to side reactions and polymerization, but metal template synthesis offers an alternative high yielding and often selective route to macrocyclic ligands with a range of geometries and potential uses [1,2]. Macrocyclic complexes of transition metal ions have a number of unique properties offered by the macrocyclic environment, such as extremely high thermodynamic stability, the ability to access unusual oxidation states of the metal [3], metal ion-selective reagents [4][5][6], models for metalloenzyme active sites [7,8], applications in biology and medicine and also as catalysts for conversion of various organic substrates [9][10][11].…”

Synthesis and characterization of cobalt(III) tetraaza macrocyclic complexes containing chloro and azido ligands

“…The application of polyaza macrocycle precursors in the synthesis of transition metal(II) macrocyclic complexes stems mainly from their use as models for protein-metal binding sites in biological systems [1][2][3][4], and as selective complexing agents for metal ions [5][6][7][8]. Recently, the cyclam and modified cyclam cobalt(III) complexes have been synthesized and structurally characterized by spectroscopy and X-ray crystallography [9][10][11][12][13][14][15].…”