Pyridinedicarboxylic acids (H2L) contg. a carboxylic group in position 2 react with Cr(III) in aq. soln. at pH < 3.5 giving sol. red-violet chelates. Only mononuclear complexes in the M/L mole ratio 1:1 and 1:2 are formed. The spectrophotometric properties and the formation consts. ([MHL]/[M][HL-] and [M(HL)2]/[M][HL-]2) of the individual complexes were calcd. at 25° in 0.5 M NaClO4. The spectrophotometric properties and the acid dissocn. consts. of the pyridinedicarboxylic acids themselves are also reported. Stability consts. decrease in the order 2,6-H2L > 3,4-H2L > 2,4-H2L > 2,3-H2L > 2,5-H2L .simeq. 3,5-H2L for 1:1 and 1:2 complexes
The reaction of chromium(III) with 2,x-pyridinedicarboxylic acids / Chiacchierini, E.; D'Ascenzo, G.; De Angelis, G.; Magri', Antonio; Petrone, V.. - In: ANNALI DI CHIMICA. - ISSN 0003-4592. - STAMPA. - 67:3-4(1977), pp. 195-210.
The reaction of chromium(III) with 2,x-pyridinedicarboxylic acids
MAGRI', Antonio;
1977
Abstract
Pyridinedicarboxylic acids (H2L) contg. a carboxylic group in position 2 react with Cr(III) in aq. soln. at pH < 3.5 giving sol. red-violet chelates. Only mononuclear complexes in the M/L mole ratio 1:1 and 1:2 are formed. The spectrophotometric properties and the formation consts. ([MHL]/[M][HL-] and [M(HL)2]/[M][HL-]2) of the individual complexes were calcd. at 25° in 0.5 M NaClO4. The spectrophotometric properties and the acid dissocn. consts. of the pyridinedicarboxylic acids themselves are also reported. Stability consts. decrease in the order 2,6-H2L > 3,4-H2L > 2,4-H2L > 2,3-H2L > 2,5-H2L .simeq. 3,5-H2L for 1:1 and 1:2 complexesI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
