774167-08-7Relevant academic research and scientific papers
Further Attempts to Rationalise the Co-ordination Chemistry of Manganese with Schiff Base Ligands and Supplementary Carboxylate Donors
Watkinson, Michael,Fondo, Matilde,Bermejo, Manuel R.,Sousa, Antonio,McAuliffe, Charles A.,et al.
, p. 31 - 42 (2007/10/03)
Some manganese(III) complexes of Schiff base ligands with ancillary carboxylate donors have been found to exhibit structural diversity, although some pattern emerged. Thus, when the ligands 3CH3O-salen and 3CH3O-salpn are used in conjunction with carboxylates RCO2- (R = Me, Et, nPr or CH2Ph) unidentate carboxylate bonding occurs as in the crystallographically observed *2H2O 1, *H2O 4, and 5. On the other hand, employing the more sterically encumbered carboxylates tBuCO2- and iPrCO2-, bidentate chelating binding of the carboxylate occurs, as in 2 and 3. The reactivity of (acac = acetylacetonate) with Me3SiCl and aliphatic carboxylic acids, RCO2H (R = Me, Et, nPr, nBu, iPr or tBu), has also been investigated. A dimer species 2>*CH3CN 6 was isolated from the reaction of Me3SiCl with while the carboxylic acids seem to lead to the isolation of monomers, such as 7. This synthetic route has also been applied to the preparation of related complexes, in which the manganese(III) centre is not attainable with reliability via the aerobic oxidation of a manganese(II) precursor, although some rare examples have been obtained by the latter method, such as , 8, . Single crystals were grown from a dimethylformamide solution of the material of stoichiometry Mn(3Br,5NO2-salpn)(O2CMe)*H2O , isolated from this route and found to consist of the unexpected 2>*3DMF 9, apparently containing a manganese(IV) species, in spite of the electron withdrawing nature of the substituents on the aromatic rings of the ligand.
