Kinetic studies in aqueous solutions of cobalt(II)-ethylenediamine, -malonate, and -glycinate complexes

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

The dynamics of equilibria in aqueous solutions of cobalt(II)-ethylenediamine (en), -malonate (mal), and -glycinate (glyO) systems have been investigated by measuring the paramagnetic relaxation rate and shift of the CH2 ligand protons over a wide range of complex formation. The formation rate constants (dm3 mol-1 s-1) of the cobalt parent complexes at 25°C and I = 1 mol dm-3 KCl are: k2 en = 3.0 × 107, k3 en = 1.1 × 107, k1 mal = 6.9 × 107, k2 mal = 1.6 × 107, k2 glyO = 2.2 × 106, and k3 glyO = 6.4 × 105. Kinetic evidence is given for the formation of [Co(Hen)]3+, [Co(Hmal)]+, and [Co(mal)3]4- complexes. The 'carboxyl-displacement' mechanism was used to interpret the interaction between [Co(glyO)3]- and the free glyO- ligand. The complex-formation kinetics of some complexes of Co2+ and Fe2+ were compared and the similarities and differences are discussed.

Original languageEnglish
Pages (from-to)2581-2586
Number of pages6
JournalJournal of the Chemical Society, Dalton Transactions
Issue number8
DOIs
Publication statusPublished - 1990

Fingerprint

ethylenediamine
Cobalt
Ligands
Kinetics
Protons
Rate constants
malonic acid

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

@article{fd8dbe1f80e249608d768c52e57dadb9,
title = "Kinetic studies in aqueous solutions of cobalt(II)-ethylenediamine, -malonate, and -glycinate complexes",
abstract = "The dynamics of equilibria in aqueous solutions of cobalt(II)-ethylenediamine (en), -malonate (mal), and -glycinate (glyO) systems have been investigated by measuring the paramagnetic relaxation rate and shift of the CH2 ligand protons over a wide range of complex formation. The formation rate constants (dm3 mol-1 s-1) of the cobalt parent complexes at 25°C and I = 1 mol dm-3 KCl are: k2 en = 3.0 × 107, k3 en = 1.1 × 107, k1 mal = 6.9 × 107, k2 mal = 1.6 × 107, k2 glyO = 2.2 × 106, and k3 glyO = 6.4 × 105. Kinetic evidence is given for the formation of [Co(Hen)]3+, [Co(Hmal)]+, and [Co(mal)3]4- complexes. The 'carboxyl-displacement' mechanism was used to interpret the interaction between [Co(glyO)3]- and the free glyO- ligand. The complex-formation kinetics of some complexes of Co2+ and Fe2+ were compared and the similarities and differences are discussed.",
author = "K. Micskei and I. Nagyp{\'a}l",
year = "1990",
doi = "10.1039/DT9900002581",
language = "English",
pages = "2581--2586",
journal = "Dalton Transactions",
issn = "1472-7773",
publisher = "Royal Society of Chemistry",
number = "8",

}

TY - JOUR

T1 - Kinetic studies in aqueous solutions of cobalt(II)-ethylenediamine, -malonate, and -glycinate complexes

AU - Micskei, K.

AU - Nagypál, I.

PY - 1990

Y1 - 1990

N2 - The dynamics of equilibria in aqueous solutions of cobalt(II)-ethylenediamine (en), -malonate (mal), and -glycinate (glyO) systems have been investigated by measuring the paramagnetic relaxation rate and shift of the CH2 ligand protons over a wide range of complex formation. The formation rate constants (dm3 mol-1 s-1) of the cobalt parent complexes at 25°C and I = 1 mol dm-3 KCl are: k2 en = 3.0 × 107, k3 en = 1.1 × 107, k1 mal = 6.9 × 107, k2 mal = 1.6 × 107, k2 glyO = 2.2 × 106, and k3 glyO = 6.4 × 105. Kinetic evidence is given for the formation of [Co(Hen)]3+, [Co(Hmal)]+, and [Co(mal)3]4- complexes. The 'carboxyl-displacement' mechanism was used to interpret the interaction between [Co(glyO)3]- and the free glyO- ligand. The complex-formation kinetics of some complexes of Co2+ and Fe2+ were compared and the similarities and differences are discussed.

AB - The dynamics of equilibria in aqueous solutions of cobalt(II)-ethylenediamine (en), -malonate (mal), and -glycinate (glyO) systems have been investigated by measuring the paramagnetic relaxation rate and shift of the CH2 ligand protons over a wide range of complex formation. The formation rate constants (dm3 mol-1 s-1) of the cobalt parent complexes at 25°C and I = 1 mol dm-3 KCl are: k2 en = 3.0 × 107, k3 en = 1.1 × 107, k1 mal = 6.9 × 107, k2 mal = 1.6 × 107, k2 glyO = 2.2 × 106, and k3 glyO = 6.4 × 105. Kinetic evidence is given for the formation of [Co(Hen)]3+, [Co(Hmal)]+, and [Co(mal)3]4- complexes. The 'carboxyl-displacement' mechanism was used to interpret the interaction between [Co(glyO)3]- and the free glyO- ligand. The complex-formation kinetics of some complexes of Co2+ and Fe2+ were compared and the similarities and differences are discussed.

UR - http://www.scopus.com/inward/record.url?scp=37049070972&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=37049070972&partnerID=8YFLogxK

U2 - 10.1039/DT9900002581

DO - 10.1039/DT9900002581

M3 - Article

AN - SCOPUS:37049070972

SP - 2581

EP - 2586

JO - Dalton Transactions

JF - Dalton Transactions

SN - 1472-7773

IS - 8

ER -