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http://hdl.handle.net/2445/127695
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DC Field | Value | Language |
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dc.contributor.author | Pérez de Benito, Joaquín F. | - |
dc.contributor.author | Martínez Cereza, Guillem | - |
dc.date.accessioned | 2019-01-29T11:17:41Z | - |
dc.date.issued | 2018-09-17 | - |
dc.identifier.issn | 1089-5639 | - |
dc.identifier.uri | http://hdl.handle.net/2445/127695 | - |
dc.description.abstract | The ligand sequential replacement on chromium(III)-aqua complexes by L-alanine in slightly acidic aqueous solutions (pH range: 3.55-5.61) has been kinetically followed by means of UV-Vis spectrophotometry. A two rate constant model has been applied to fit the absorbance-time data, corresponding to the formation (k1) and decay (k2) of an intermediate not reactive enough to be in steady state (long-lived intermediate). The kinetic orders of the amino acid were fractional (0.40 ± 0.03 for k1 and 0.40 ± 0.02 for k2). The two steps showed base catalysis, and the activation energies were 60 ± 3 (for k1) and 83 ± 6 (for k2) kJ mol-1. The rate constants for the coordination of the first L-alanine ligand followed the sequence CrOH2+ < Cr(OH)2+ < Cr(OH)3, Cr3+ being almost inactive. This suggests that the increase in the reaction rate with increasing pH was caused by the enhancement of the lability of the Cr(III)-aqua bonds induced by the presence of hydroxo ligands. The activation parameters for a series of ligand substitution on Cr(III)-aqua complexes by organic molecules yielded a statistically significant enthalpy-entropy linear plot with an isokinetic temperature of 296 ± 21 K. | - |
dc.format.extent | 49 p. | - |
dc.format.mimetype | application/pdf | - |
dc.language.iso | eng | - |
dc.publisher | American Chemical Society | - |
dc.relation.isformatof | Versió postprint del document publicat a: https://doi.org/10.1021/acs.jpca.8b07824 | - |
dc.relation.ispartof | Journal of Physical Chemistry A, 2018, vol. 122, num. 40, p. 7962-7973 | - |
dc.relation.uri | https://doi.org/10.1021/acs.jpca.8b07824 | - |
dc.rights | (c) American Chemical Society , 2018 | - |
dc.source | Articles publicats en revistes (Ciència dels Materials i Química Física) | - |
dc.subject.classification | Crom | - |
dc.subject.classification | Cinètica química | - |
dc.subject.classification | Aminoàcids | - |
dc.subject.other | Chromium | - |
dc.subject.other | Chemical kinetics | - |
dc.subject.other | Amino acids | - |
dc.title | Ligand sequential replacement on chromium(III)-aqua complexes by L-alanine and other biological amino acids: a kinetic perspective | - |
dc.type | info:eu-repo/semantics/article | - |
dc.type | info:eu-repo/semantics/acceptedVersion | - |
dc.identifier.idgrec | 684982 | - |
dc.date.updated | 2019-01-29T11:17:41Z | - |
dc.rights.accessRights | info:eu-repo/semantics/openAccess | - |
dc.identifier.pmid | 30222935 | - |
Appears in Collections: | Articles publicats en revistes (Ciència dels Materials i Química Física) |
Files in This Item:
File | Description | Size | Format | |
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684982.pdf | 811.25 kB | Adobe PDF | View/Open |
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