𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Kinetics and equilibrium study of nickel(II) complexation by pterin

✍ Scribed by Víctor D. Monópoli; Andrés H. Thomas; Alberto L. Capparelli

Publisher
John Wiley and Sons
Year
2000
Tongue
English
Weight
142 KB
Volume
32
Category
Article
ISSN
0538-8066

No coin nor oath required. For personal study only.

✦ Synopsis

The kinetics of complexation of Ni(II) by pterin was studied in aqueous solutions with a stopped-flow apparatus under conditions of pseudo-first order in the temperature range 5-45ЊC, pH between 4.0 and 6.5, and ionic strength 0.4 M. The equilibrium constants, stoichiometry, and pK a of the ligand and complex were also determined using a spectrophotometric technique. The results are consistent with the formation of a 1 : 1 complex between the metal ion and pterin. The first-order experimental rate constant k app is pH independent and shows the following dependence with the ion metal concentration at 25ЊC: k app /s Ϫ1 ϭ 3.8 ϫ 10 Ϫ3 ϩ 1.6 ϫ 10 Ϫ4 ϫ [Ni(II)] Ϫ1 . A global activation energy of 57 Ϯ 2 kJ/mol associated with the formation of a 1 : 1 chelate was measured.

📜 SIMILAR VOLUMES

Nickel(II) Tetraazamacrocyclic Complexes
Nickel(II) Tetraazamacrocyclic Complexes with Two Pendant Amino Groups: Electrochemical and Kinetic Studies
✍ Bohdan Korybut-Daszkiewicz; Joanna Taraszewska; Bohdan Kamieński 📂 Article 📅 2001 🏛 John Wiley and Sons 🌐 English ⚖ 349 KB

7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecanenickel(II) and -4,11-dienenickel(II) complexes (1-4) were studied by cyclic voltammetry. The thermodynamic stability of Ni III was the greatest in complex 4 with a trans configuration of the pendant amino groups. On acidification, the Ni II /Ni

Kinetics and equilibrium constants of so
Kinetics and equilibrium constants of some pentacyanoferrate(II) complexes of nitrogen and sulfur containing heterocycles
✍ Yakup Baran; Ahmet Ülgen 📂 Article 📅 1998 🏛 John Wiley and Sons 🌐 English ⚖ 127 KB 👁 2 views

The kinetics of the substitution reactions of ion with a series of 3Ϫ Fe(CN) H O 5 2 nitrogen and sulfur containing heterocycles were studied in aqueous media. In the presence of excess ligand, varied over a large range of concentrations, second-order rate constants were calculated at Activation par

Structural Study of Nickel(II), Copper(I
Structural Study of Nickel(II), Copper(II), and Palladium(II) Complexes of 2-Pyridineformamide 3-Hexamethyleneiminylthiosemicarbazone
✍ Karen A. Ketcham; Isabel Garcia; Elena Bermejo; John K. Swearingen; Alfonso Cast 📂 Article 📅 2002 🏛 John Wiley and Sons 🌐 German ⚖ 262 KB 👁 2 views

Reduction of 2-cyanopyridine by sodium in the presence of 3-hexamethyleneiminylthiosemicarbazide produces 2-pyridineformamide 3-hexamethyleneiminylthiosemicarbazone, HAmhexim. Complexes with nickel(II), copper(II) and palladium(II) have been prepared and the following complexes structurally characte

Equilibrium and kinetic studies of the c
Equilibrium and kinetic studies of the cooperative I ⇌ II transition in poly-L-proline
✍ Jürgen Engel 📂 Article 📅 1966 🏛 Wiley (John Wiley & Sons) 🌐 English ⚖ 240 KB 👁 1 views

The synthetic polymer poly-L-proline exists in two conformational forms, I and 11, the structures of which have been elucidated by x-ray crystallography.'-3 Form I is a right-handed helix with all peptide bonds in the cis configuration, and is stable in pyridine and aliphatic alcohols. Form I1 is a