STABILITY CONSTANTS OF SOME RARE-EARTH-METAL CHELATES

Journal Article · Sun Apr 01 04:00:00 EST 1962 · Dissertation Abstr.

OSTI ID:4820778

Karraker, R H

The first three successive formation or stability constants of the rare- earth complexes with glycolic and lactic acids were measured at an ionic strength of 0.1 and at 20 plus or minus 0.02 deg C. The method used involved a potentiometric measurement of pH with a glass electrode. With both ligands, the first stability constants increased in value with increasing atomic number of the central ion across the series from lanthanum to europium, and again from gadolinium to lutetium. There was, however, a decrease between europium and gadolinium which caused an overlap between the two halves of the series. This overlap was more pronounced with glycolate than with lactate. The lactate stability constants were stronger than the corresponding glycolate constants, and both were much stronger than the rare-earth acetate constants. The glycolate constants were found to be over twice as strong as had been previously reported at 2.0 ionic strength. It was postulated that the complexing agents were bidentate ligands with the aydroxyl group participating in the chelate formation. The stability consthnts of the rare-earth chelates with 1,2diaminocyclohexane- N,N,N ,N -tetraacetic acid were determinined by polarographic comparison with cadmium, zinc, and europium complexes at 0.1 ionic strength and 20 plus or minus 0.02 deg C. These constants were found to increase linearily with atomic number across the complete series with the exception of gadolinium and possibly lanthanum. Both the gadolinium and lanthanum constants were low, but the margin of error in the lanthanum constant determination was relatively large.

• Research Organization: Iowa State Univ. of Science and Tech., Ames
• NSA Number: NSA-16-023684
• OSTI ID: 4820778
• Journal Information: Dissertation Abstr., Journal Name: Dissertation Abstr. Vol. Vol: 22
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ACETATES
ACETIC ACID
ACIDITY
AMINES
ATOMS
BINDING ENERGY
CADMIUM COMPLEXES
CHELATES
CHEMISTRY
COMPLEXES
CYCLOALKANES
ELECTRIC CHARGES
ELECTRIC POTENTIAL
ELECTRODES
ELECTROLYTES
ERRORS
EUROPIUM COMPLEXES
GLASS
GLYCOLIC ACID
HEXANE
IONIC STRENGTH
IONS
LACTIC ACID
LIGANDS
MEASURED VALUES
NUMERICALS
ORGANIC ACIDS
QUALITATIVE ANALYSIS
QUANTITATIVE ANALYSIS
RARE EARTHS
STABILITY
ZINC COMPLEXES