The impact of tripodal chelates on water exchange kinetics and mechanisms: A variable temperature and pressure 17O NMR study to clarify the structure-reactivity relationship in [FeII(L)(H2O)2]− complexes

2008 ◽  
Vol 46 (S1) ◽  
pp. S94-S99 ◽  
Author(s):  
Joachim Maigut ◽  
Roland Meier ◽  
Achim Zahl ◽  
Rudi van Eldik
Keyword(s):  
Water Exchange ◽  
Variable Temperature ◽  
17O Nmr ◽  
Nmr Study ◽  
Exchange Kinetics ◽  
Temperature And Pressure ◽  
Structure Reactivity Relationship ◽  
The Impact

Rates of Water Exchange in 2,2′-Bipyridine and 1,10-Phenanthroline Complexes of CoII and MnII

2017 ◽  
Vol 70 (6) ◽  
pp. 751 ◽  
Author(s):  
Shravan S. Acharya ◽  
Bjorn Winther-Jensen ◽  
Leone Spiccia ◽  
C. André Ohlin
Keyword(s):  
Nmr Spectroscopy ◽  
Water Exchange ◽  
Variable Temperature ◽  
Activation Parameters ◽  
Cobalt Complexes ◽  
Degree Of Substitution ◽  
Manganese Complexes ◽  
17O Nmr ◽  
17O Nmr Spectroscopy

The rates and activation parameters of water exchange at pH 3.0 have been determined using variable temperature 17O NMR spectroscopy for four CoII complexes and one MnII complex: [Co(bpy)(H2O)4]2+, [Co(bpy)2 (H2O)2]2+, [Co(phen)-(H2O)4]2+, [Co(phen)2 (H2O)2]2+, and [Mn(bpy)(H2O)4]2+ (bpy = 2,2′-bipyridyl and phen = 1,10-phenanthroline). Substitution of aquo ligands with 1,10-phenanthroline or 2,2′-bipyridyl leads to an increase in the rate of exchange in the manganese complexes, from k298 (1.8 ± 0.1) × 107 s−1 for [Mn(H2O)6]2+ to (7.2 ± 0.3) × 107 s−1 for [Mn(phen)2 (H2O)2]2+, whereas the trends are more complex for the cobalt complexes. We have used the new data in conjunction with literature data for similar complexes to analyse the effect of M–OH2 distance and degree of substitution.

Variable-Temperature and Variable-Pressure17O-NMR Study of Water Exchange of Hexaaquaaluminium(III)

1985 ◽  
Vol 68 (3) ◽  
pp. 545-554 ◽  
Author(s):  
Deirdre Hugi-Cleary ◽  
Lothar Helm ◽  
Andr� E. Merbach
Keyword(s):  
Water Exchange ◽  
Variable Temperature ◽  
Nmr Study
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