Über die Kinetik der Dissoziation und Bildung von Ni‐Chelat‐Komplexen verschiedener zweizähniger Liganden (Hydroxycarboxylaten, Aminocarboxylaten, Dicarboxylaten)

Hoffmann, H.

doi:10.1002/bbpc.19690730503

Ber Bunsenges Phys Chem

1969

DOI: 10.1002/bbpc.19690730503

|View full text |Cite

Über die Kinetik der Dissoziation und Bildung von Ni‐Chelat‐Komplexen verschiedener zweizähniger Liganden (Hydroxycarboxylaten, Aminocarboxylaten, Dicarboxylaten)

H. Hoffmann

Abstract: Die experimentell ermittelten Geschwindigkeitskonstanten für die Komplexbildung und Dissoziation zwischen Ni2+‐Ionen und einer Reihe zweizähniger Liganden, bei denen wenigstens eine Haftstelle eine Carboxylatgruppe ist, werden in die spezifischen Geschwindigkeitskonstanten zerlegt, die bei der Chelatbildung zu berücksichtigen sind. Es zeigt sich, daß die größere Stabilität von 5‐Ringen gegenüber entsprechenden 6‐Ringen hauptsächlich auf der kleineren Geschwindigkeitskonstante für die Ringöfffnung beruht.

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...

Citation Types

Supporting

Mentioning

Contrasting

Year Published

1970

2001

Publication Types

Select...

Article5

Relationship

Self Cite0

Independent5

Authors

Journals

Cited by 15 publications

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

Kinetics of the Interaction of Indium(III) with 8-Quinolinol-5-sulfonic Acid and with Sulfate

et al. 2001

View full text Add to dashboard Cite

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.

show abstract

Kinetics of the Interaction of Indium(III) with 8-Quinolinol-5-sulfonic Acid and with Sulfate

et al. 2001

View full text Add to dashboard Cite

show abstract

The Effect of Various Inner Coordination Sphere Ligands on the Dissociation Rate of Nickel Malonate Complexes

Hoffmann

Yeager

1970

Ber Bunsenges Phys Chem

View full text Add to dashboard Cite

The effects of a number of strongly bonding ligands on the dissociation rates of malonate bidentate nickel complexes have been examined in aqueous nickel malonate solutions using the pressure‐step and shock wave relaxation technique with conductivity readout. The opening of the malonate chelate appears to be the rate controlling step in the dissociation of the malonate. The dissociation rate constant has been compared with the observed shift in the optical absorption peaks for the d – d orbital transitions in the various mixed nickel complexes. On the basis of the comparison the various ligands other than malonate and water in the inner coordination sphere of nickel have been divided into three classes:1. ligands that labilize the malonate chelate with the logarithm of the rate constant increasing as a linear function of the spectral shift to shorter wavelengths (e.g., pyridine, 2‐aminoethyl pyridine, ethylenediamine, 3,3′‐iminopropylamine).2. ligands which produce only a small effect on the dissociation rate of the malonate complex although producing a substantial spectral shift to shorter wavelengths (e.g., α,α′‐bipyridine, phenanthroline, pyridine 2‐aldoxime).3. ligands which labilize the malonate complex but do not produce any appreciable spectral shift (e.g., acetylacetone).These effects are discussed in terms of charge on the ligand, crystal field stabilization energies and σ and π orbital character of the bonding.

show abstract

Eine Stoßwellenapparatur zur Untersuchung von schnellen Reaktionen in Lösungen. Messungen an Magnesiumkomplexen

Platz¹,

Hoffmann²

1972

Ber Bunsenges Phys Chem

View full text Add to dashboard Cite

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

customersupport@researchsolutions.com

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Über die Kinetik der Dissoziation und Bildung von Ni‐Chelat‐Komplexen verschiedener zweizähniger Liganden (Hydroxycarboxylaten, Aminocarboxylaten, Dicarboxylaten)

Cited by 15 publications

References 23 publications

Kinetics of the Interaction of Indium(III) with 8-Quinolinol-5-sulfonic Acid and with Sulfate

Kinetics of the Interaction of Indium(III) with 8-Quinolinol-5-sulfonic Acid and with Sulfate

The Effect of Various Inner Coordination Sphere Ligands on the Dissociation Rate of Nickel Malonate Complexes

Eine Stoßwellenapparatur zur Untersuchung von schnellen Reaktionen in Lösungen. Messungen an Magnesiumkomplexen

Contact Info

Product

Resources

About