Premium
Quantitative 2D EXSY and Dynamic 19 F‐NMR Studies of the Dynamic Behaviour of the Bidentate Chelate Complex Ga(fox) 3 (fox = 5‐fluoro‐8‐hydroxyquinoline)
Author(s) -
Gromova Marina,
Jarjayes Olivier,
Hamman Sylvain,
Nardin Robert,
Béguin Claude,
Willem Rudolph
Publication year - 2000
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/(sici)1099-0682(200003)2000:3<545::aid-ejic545>3.0.co;2-2
Subject(s) - chemistry , chelation , 8 hydroxyquinoline , intramolecular force , denticity , nmr spectra database , metal , nuclear magnetic resonance spectroscopy , tris , proton nmr , crystallography , stereochemistry , spectral line , inorganic chemistry , organic chemistry , biochemistry , physics , astronomy
The rates of intramolecular rearrangement of the meridional isomer of the metal tris ‐chelate complex [Ga(fox) 3 , fox = 5‐fluoro‐8‐hydroxyquinoline] in DMF solution were measured using 1D NMR line shape analysis and 2D EXSY spectra. The rates of exchange k ab , k bc and k ac between the three non‐equivalent ligands a , b and c were determined. The values of the activation parameters were obtained. ΔH ‡ was 70.6 kJ mol –1 for all the rate constants. ΔS ‡ was different in each of the three cases: ΔS ‡ ab , ΔS ‡ bcand ΔS ‡ acwere 27.7, 28.5 and 34.6 J K –1 mol –1 respectively. The interpretation of these data was related to the discrimination of different twist processes (Bailar and Rây–Dutt) for intramolecular rearrangement of the tris ‐chelate complex.