Uncharged encapsulated iron(II) complexes: transfer chemical potentials and solvation in water-methanol and water-t-butanol mixtures

Kinetic, solvation and reactivity studies of iron(II) complexes of monoxime and dioxime ligands

“…A phenyl group is considerably more hydrophobic than a methyl group or a proton for iron(II)-oxime complex cation, thus the results show preferential solvation by methanol as ligand size and hydrophobicity increase. Figure 4 includes plots for earlier-established trends for two hexadentate dioximatoiron(II) cations [10], for an encapsulated iron(II) complex of a borate-capped Tris-dioxime cage [ Figure 1(c) with R ¼ O n Bu, [31]], and for the most hydrophilic and most hydrophobic iron(II)-tris-diimine cations [10,32], to put the trends for the present oxime complexes in context. This Figure also includes the transfer chemical potential trend [33] for the uncharged binuclear bis-dioxime complex [(Hdapd)ClFe(l-Cl) 2 FeCl(dapd)], whose relatively hydrophilic chloride ligands partially compensate the hydrophobicity of the dapd moities.…”

Solvation of iron(II) complexes of hexadentate tris-diimine Schiff base tripod ligands in alcohol?water and DMSO?water mixtures

“…Iron(II) complexes of linear [6] and encapsulating [7] hexadentate tris-diimine ligands tend to be exceptionally inert to substitution -cage complexes such as (1) and complexes of linear hexadentate ligands such as (2) have half-lives with respect to base hydrolysis of several hours in 0.33 mol dm À3 hydroxide [8,9], while aquation in acidic media is even slower. Such inertness to substitution makes this type of complex extremely useful for kinetic studies, especially of oxidation by such slow oxidants as peroxodisulphate [10] or thallium(III) [11], where often rate-limiting dissociation, with subsequent oxidation of iron(II) intermediates, occurs in parallel with, or faster than, direct oxidation [12], thus making kinetic studies difficult or impossible.…”