Solvent effects on solubility, reactivity and spectroscopy of inorganic complexes
Transfer chemical potential trends have been determined from solubility measurements for uncharged encapsulated and semi-encapsulated iron(II) complexes, and for series of ?-diketonate metal complexes, in water-alcohol and water- dimethyl sulphoxide mixtures. These solubilities were obtained by spectrophotometry and atomic absorption spectrometry. The transfer chemical potentials are discussed in terms of ligand periphery and solvent nature. Reactivities for base hydrolysis of series of iron(II) diimine complexes, containing diazabutadiene, pyridine- derived Schiff base, terdentate, linear hexadentate, tripod and encapsulating cage ligands, in aqueous and aqueous-dimethyl sulphoxide mixtures have been determined, in order to examine second-order rate constants for base hydrolysis and their relation to ligand structure. Correlations between rate constants and respective electrode potentials have been considered for a series of diazabutadiene and pyridine-containing Schiff base complexes. Solvent effects on second-order rate constants for base hydrolysis of two iron (II) diimine complexes have been analysed in terms of initial state and transition state contributions. The effects of a2+ fluoro-substituted cosolvent on reactivity of [Fe (gei) 3] is reported and compared with those of analogous alcohols. Dependences of wavenumbers of maximum absorption for the lowest energy metal to ligand charge-transfer band of ternary iron (II) cyanide diimine complexes have been reported in series of binary aqueous solvent mixtures. The v max values for Fe (CN)2 ( phen) in non-aqueous solvents have examined in relation to Reichardt ET(30) values and solvent acceptor numbers, and the versatility of the complex as a probe of solvent polarity discussed. The v max values for Fe (CN) 2 (bipy) 2 in various hydroxylic media and hydroxylic-aqueous mixtures have been reported, and the usefulness of this complex as a probe for solvation trends for these media examined. The solvatochromic behaviour for Ti(Cp)2 (NCS)2, [W(CN) 6 (bipy)]2- and [W0(CN)3(bipy)2] in various non-aqueous solvents is reported, and the solvent sensitivities of these are complexes compared with those of ternary iron(II) cyanide diimine complexes.