Interaction Of Indium Research Articles

Kinetics of the interaction of indium(III) with 8-quinolinol-5-sulfonic acid and with sulfate.

The kinetics and equilibria of indium(III) binding to 8-quinolinol-5-sulfonic acid (HQSA) have been investigated in acidic aqueous solution at 0.2 M ionic strength and 25 C by stopped-flow, absorption and fluorescence spectrometric methods. Absorption and fluorescence spectrometry revealed that a monoprotonated MHL3+ complex is formed in addition to the ML2+ chelate. The stability constants of the chelate (log K(ML) 6.53). of the monoprotonated complex (logK(MHL = 3.5l) and its acid dissociation constant (pK(C2) = 1.4) have been determined. Stopped-flow measurements indicate three reaction paths that involve the interaction of M3+ with H2L+ (k1 =(3.21 +/- 0.04) x 10(2) m(-1) s(-1)), M3+ with HL (k2=(6.52 +/- 0.04) x 10(4) M(-1)s(-1)) and MOH2+ with HL (k3 = (1.60 +/- 0.08) x 10(6) M(-1) s(-1)), respectively. The reactivity of In3+ toward the uncharged form of HQSA has been found to be approximately two orders of magnitude less than expected based upon water exchange experiments. This behaviour has been explained with the assumption that the ligand is distributed between two forms (neutral and zwitterion) of which only the neutral form is reactive. The rate of complex formation between In3+ and SO4(2-) ion has been measured by the temperature-jump method with Tropaeolin 00 as the indicator. The second-order rate constant of the binding process is 5.1 x 10(4) M s(-1). This quantity yields a value for the first-order rate constant of 570 s(-1) for ligand penetration into the In3+ coordination shell, approximately two orders of magnitude less than normal. This finding is interpreted by the hypothesis that SO4(2-) forms a chelate with In3+ for which ring closure is the rate-determining step.

Kinetics and Equilibria of the Interaction of Indium(III) with Pyrocathecol Violet by Relaxation Spectrometry

A temperature-jump apparatus with laser light sources was used to investigate the binding mechanism of indium(III) to pyrocathecol violet (3,3‘,4‘- trihydroxyfuchsone-2-sulfonic acid, whose neutral form is denoted as H4L). Spectrophotometric measurements revealed that for [H+] > 0.015 M, the main bound species are MH3L2+ and MH2L+ whereas for [H+] < 0.015 M, the main bound species is M2L2+. Two relaxation effects were observed. The fast relaxation is associated mainly with the reaction steps M3+ + H3L- ↔ MH3L2+ (k2 = 1.2 × 106 M-1 s-1, k-2 = 1.5 × 105 s-1) and MOH2+ + H3L- ↔ MH2L+ (k3 = 4.4 × 107 M-1 s-1, k-3 = 7.4 × 102 s-1). The rate constant k2 decreases, whereas k-2 increases, with increasing ionic strength. Addition of Na2SO4 results in a large reduction of the fast relaxation time that is ascribed to the binding of indium(III) to sulfate. Analysis of the relaxation time dependence on the sulfate concentration provides the binding constant of the indium−sulfate complex (K = 1.5 × 102 M-1). The activation parameters for the step M3+ + H3L- ↔ MH3L2+ were obtained as ΔH1f⧧ = 25.3 kJ mol-1, ΔS1f⧧ = −6.2 J mol-1 K-1, ΔH1d⧧ = 13.4 kJ mol-1, ΔS1d⧧ = −57 J mol-1 K-1. The enthalpy change of the just described reaction step was measured by spectrophotometry at different temperatures and by the relaxation amplitudes, the average value being ΔH10 = 11.9 kJ mol-1. The slow effect is associated with a complexation path leading to formation of M2L+. The amplitude analysis of the slow relaxation gives ΔH20 = 7.6 kJ mol-1. A comparison of this work with other studies on complexation with indium(III) suggests that In(OH)2+ reacts according to the Id mechanism, whereas the mode of activation of In(H2O)63+ seems to be less definite because a clear indication about the dependence (or independence) of the rates on the ligand basicity does not emerge. This observation and the slightly negative value of ΔS1f⧧ hints at the possibility that indium(III) undergoes complexation by a concerted mechanism.

The interaction of indium(III) iodide species with substituted ortho- and para-quinones

The interactions of substituted ortho- and para-quinones with indium(III) halides and the InI4– anion have been studied in non-aqueous solution. para-Quinones and InI3 give rise to stable 1∶1 adducts, which are diamagnetic in the solid state, but which decompose in solution to form (p-sq)InI2 derivatives, where p-sq˙– is the corresponding semiquinonate. With ortho-quinones, the reaction products are (o-sq)InI2 which react with 4-methylpyridine (pic) to form (o-sq)InI2pic2. The electron spin resonance spectra of these products, and their solution chemistry, are discussed. The reactions involve intramolecular one-electron transfer, resulting in oxidation of the iodide ligand. In contrast, the reaction of 3,5-di-tert-butyl-1,2-benzoquinone with InI4– apparently involves intermolecular electron transfer; in this case, the products are I3– and the corresponding catecholate (dbc), isolated as the solid InI(dbc)pic2. The mechanisms of these various processes are discussed.

ChemInform Abstract: Equilibria and Mechanism of the Interaction of Indium(III) with the Indicator 1‐(2‐Pyridylazo)‐2‐naphthol (PAN) (investigations in methanol‐water mixtures, formation of a 1:1 complex.

ChemInform Abstract: Equilibria and Mechanism of the Interaction of Indium(III) with the Indicator 1‐(2‐Pyridylazo)‐2‐naphthol (PAN) (investigations in methanol‐water mixtures, formation of a 1:1 complex.

Equilibria and mechanism of the interaction of indium(III) with the indicator 1-(2-pyridylazo)-2-naphthol (PAN)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEquilibria and mechanism of the interaction of indium(III) with the indicator 1-(2-pyridylazo)-2-naphthol (PAN)Berta Perlmutter-Hayman, Fernando Secco, and Marcella VenturiniCite this: Inorg. Chem. 1985, 24, 23, 3828–3831Publication Date (Print):November 1, 1985Publication History Published online1 May 2002Published inissue 1 November 1985https://doi.org/10.1021/ic00217a026RIGHTS & PERMISSIONSArticle Views86Altmetric-Citations7LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (487 KB) Get e-Alerts Get e-Alerts

Coordination Compounds of Indium. Part XV. The Stability Constants of some Trifluoromethyl-β-diketonate Complexes of Indium (III)

The stability constants K1 and K2 have been measured for the interaction of indium(III) with the ligands R•CO•CH2•CO•CF3 (R = 2-furyl, 2-thienyl, phenyl, 2-naphthyl, i-butyl, and (t-butyl). The pKa values for these compounds, and for R = 3-pyridyl and methyl, are also reported. A conventional potentiometric technique was used; the results refer to 46% aqueous acetone, at an ionic strength of approximately 0.1 M. The results are compared with published values for complexes of these ligands with divalent cations in other solvent systems.