Marttand S. Patel

Solvation of iron and chromium complexes in alcohol-water mixtures

Solubilities are reported for the perchlorates of five iron(II)-diimine complexes in t-BuOH–H2O and one in MeOH–H2O mixtures, for three iron(III)-3-hydroxy-4-pyranonate and three iron(III)-3-hydroxy-4-pyridinonate complexes in MeOH–H2O and t-BuOH–H2O, and for two chromium(III)-3-hydroxy-4-pyranonate complexes in MeOH–H2O. Transfer chemical potentials are thence derived for the various iron(II), iron(III) and chromium(III) complexes, for transfer from H2O into the respective mixed solvents (at 298.2 K). These results are combined with values reported earlier for related complexes, and for other alcohol–H2O mixtures, to give an overall picture of solvation, expressed in the thermodynamic format of transfer chemical potentials, for iron(II)-diimine, iron(III)-3-hydroxy-4-pyridinonate and chromium(III)-3-hydroxy-4-pyranonate complexes in H2O-rich aqueous-alcohol mixtures. Some spectroscopic (1H-n.m.r.; i.r.) and kinetic (aquation rate constants at 298.2 K) data are reported for the chromium(III) complexes.

Solvatochromism and piezochromism of pentacyanoferrate(II) complexes in binary aqueous solvent media

SummaryThe solvatochromic behaviour of a number of pentacyano-ferrates (II), [FeII(CN)5L]n-, is described, for solutions in H2O-alcohol, -Me2CO and -DMSO mixtures. The strong dependence of solvent sensitivity on the nature of the ligand L is particularly fully documented for H2OMeOH mixtures (0–100% MeOH). The piezochromic behaviour of seven pentacyanoferrates(II) has been established, in aqueous solution. The connection between piezochromism and solvatochromism is detailed, and the solvatochromic results discussed in terms of (preferential) solvation.

Solvation of ethylmaltol and of its iron(III) complex

SummarySolubilities of tris(ethylmaltolato)iron(III) (ethylmaltol = 3-hydroxy-2-ethyl-4-pyrone) were measured in MeOH-H2O, t-BuOH-H2O and diol-H2O mixtures, and in several primary alcohols. Solvation of the ethylmaltol ligand and of two 4-pyridinone analogues has been investigated through solubility measurements in MeOH- H2O and in t-BuOH-H2O mixtures, and in a series of primary alcohols. The solvation characteristics of these compounds are compared with those of the parent maltol, its iron(III) complex and a number of other nonelectrolytes.

Self-Indicating Surfactants: Potentially Micellar Solvatochromic Iron(II) Complexes

Abstract The preparation of ternary iron(II) complexes [Fe(CN)2(LL)2] and [Fe(CN)4(LL)]2-, where LL = a Schiff base derived from 2-acetyl pyridine and a long chain amine 1-Me(CH2)nNH2 (n = 11, 15, 17), is described. These complexes exhibit strong solvatochromism and can thus be used to probe solvation in organised aqueous media, as in ternary water - Aerosol OT- hexanol mixtures. They also have a dramatic effect on the micellisation behaviour of the uncharged surfactant Triton X-100.

Solvation of inorganic complexes in octanol-water, hexanol-water, and related microemulsions

Abstract Solubilities of tris(ethylmaltolato)iron(III) have been determined in dry 1-octanol, 1-hexanol and isobutanol and in the limited ranges of alcohol-water binary mixtures accessible for these alcohols. The observed pattern is discussed in terms of particularly favourable synergic solvation in the mixed solvents and is compared with solvation patterns indicated by the solvatochromic iron(II) complex Fe(CN) 2 (bipy) 2 .

Pentacyanoferrates(II): solvatochromism and reactivity in micelles and in reversed micelles

Rate constants for dissociation of pyridine derivatives from pentacyanoferrates(II), [Fe(CN)5(Xpy)]3–, in micelles and in reversed micelles reflect significant interactions between the leaving ligands and the micelle or the water in the interior of the reversed micelle. These interactions can be probed through the solvatochromism of these pentacyanoferrates(II).

SOLVATION OF ALUMINIUM(III) AND IRON(III) COMPLEXES OF HYDROXAMATE LIGANDS IN ALCOHOL-WATER MIXTURES

Abstract Solubilities and derived transfer chemical potential trends are reported for several tris(hydroxamato)-aluminium(III) and iron(III) complexes in methanol-water and in t-butylalcohol-water solvent mixtures. These trends are discussed in terms of hydrophilic and hydrophobic characteristics of the peripheries of these complexes.

Solvation of platinum anti-cancer drugs in methanol-water mixtures

Solubilities and transfer chemical potentials of carboplatin, cisplatin, iproplatin, and several related platinum complexes have been determined in methanol-water mixtures. the range of solvation behaviour is discussed in relation to possible oral administration of complexes of this type.

Enthalpies and entropies of solution of tris(3-hydroxy-1,2-dimethylpyridin-4-onato)aluminium(III) in methanol–water mixtures from temperature dependences of solubilities

Solubilities of tris(3-hydroxy-1,2-dimethylpyridin-4-onato)aluminium(III), AlL3, have been determined in a series of methanol–water solvent mixtures (0, 20, 40, 60, 80 and 100% methanol) over the temperature range 278.2 to 310.2 K. Solubility maxima are independent of temperature. Enthalpies and entropies of solution exhibit compensation. Maxima in thermodynamic solution parameters do not correspond to maximal solvent structural effects and are therefore assignable to solute–solvent rather than to solvent–solvent interactions.