The regularities in stability constants of some rare earth complexes

Fidelis, I.; Siekierski, S.

doi:10.1016/0022-1902(66)80243-9

Cited by 123 publications

(36 citation statements)

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“…Tetrad effects appear as subtle zig-zag variations in their chondrite-nor malized abundance patterns (Masuda and Ikeuchi, 1979;Masuda et al, 1987;Masuda and Akagi, 1989;Kawabe et al, 1991;Akagi et al, 1993;Lee et al, 1944). The tetrad effect (or double-double effect) itself has originally been proposed for the characteristic variations of logarithmic distribution coefficients of trivalent lanthanide ions (Ln3+) in experimental studies of mutual separation of Ln3+ by phase partition chromatography (Fidelis and Siekierski, 1966) and liquid-liquid extraction of lanthanide and actinide ions (Peppard et al, 1969(Peppard et al, , 1970. This experimental proposal has been interpreted im mediately by the refined spin-pairing energy theory (RSPET) for (4f)q electronic configurations of Ln3+ (Jorgensen, 1970;Nugent, 1970).…”

Section: Introductionmentioning

confidence: 99%

Tetrad effects and fine structures of REE abundance patterns of granitic and rhyolitic rocks: ICP-AES determinations of REE and Y in eight GSJ reference rocks.

Kawabe

1995

Geochem. J.

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All fourteen REE and Y have been determined for eight GSJ reference rocks including granitic and rhyolitic samples by ICP-AES with a preconcentration method. The two rhyolites (JR-1 and JR-2) and one granite (JG-2) exhibit convex tetrad effects of the M-type even in their chondrite-normalized REE patterns. Their tetrad effects, however, are modified from ideal ones by some step-like variations in their abundances from Tm to Lu. Similar step-like irregularities are seen commonly in chondrite-normalized patterns of other samples: granodiorites (JG-1, JG-la, and JG-3), a fresh water lake sediment (JLk-1), and an alkali basalt (JB-1). We normalized the REE analyses for JR-1, JR-2, and JG-2 by those for JB-1, and then found that they clearly indicate quite regular convex tetrad effects of the M-type without apparent irregu larities in heavy REE. The other samples, when similarly normalized by JB-1, also display analogous but less marked convex tetrad effects except for JG-3. Our present results are strong evidence for the tetrad effect in magmatic processes relevant to granitic and rhyolitic rocks formations. There are common chemical characteristics among JG-2, JR-l, and JR-2: (1) large negative Eu anomalies, and (2) rather high F contents of about 1,000 ppm. The chemical characteristics and the theoretical basis of tetrad effects may suggest that the granitic and rhyolitic rocks with the convex tetrad effects of the M-type are residual silicate melts having partitioned REE with fluids in late stages of differentiation processes. The basalt-normalization appears to be so effective for extracting tetrad effects of granitic and rhyolitic rocks. It filters off the REE characteristics common in magmatic products like the step-like irregularities in heavy REE abundances when normalized by chondrite. This makes it easier to identify lanthanide tetrad effects in magmatic rocks.

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Section: Introductionmentioning

confidence: 99%

Tetrad effects and fine structures of REE abundance patterns of granitic and rhyolitic rocks: ICP-AES determinations of REE and Y in eight GSJ reference rocks.

Kawabe

1995

Geochem. J.

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“…This effect was first pointed out by Fidelis and Siekierski (1966) based on their ex perimental data for the phase partition chroma tography. Peppard et al (1969) experimentally disclosed it in liquid-liquid solvent extraction.…”

Section: Introductionmentioning

confidence: 99%

Approximate estimation of the degree of lanthanide tetrad effect from the data potentially involving all lanthanides.

Minami

Masuda

1997

Geochem. J.

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Here is presented a mathematical method which enables us to evaluate the degrees of lanthanide tetrad effects from the data involving all of REE. Each of the four spans corresponding to four subgroups, La Nd, Pm-Gd, Gd-Ho, and Er-Lu, is approximately fitted to a quadratic function and the resultant quadratic coefficient is employed as a numerical indicator for the tetrad effect. For the purpose of approximation by a quadratic function, the least-squares method is used under the constraint that the first and second quadratic curves intersect at the middle point between Pm and Sm, and that the third and fourth ones intersect at the middle point between Ho and Er. Since, mathematically, the subject is a problem on the conditional extremum, the method of Lagrange undetermined multipliers should be used. It is noted that the degrees of four tetrad effects can be evaluated simultaneously. This method can lead us to the mathematically well-defined estimation of the tetrad effect.

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“…In analogy with the difference in ion exchange properties described by FIDELIS (1970), and FIDELIS and SIEKIERSKI (1965, 1966, 1967, we suggested that orbital splitting and crystal field relations influence the distributions of the lanthanoid elements between minerals under a wide variety of geologic conditions (ROALDSET and CHRISTIE, 1975).…”

Section: Introductionmentioning

confidence: 87%