Isomeric forms of tris-Schiff base complexes of iron(II): structure of the complex derived from 2-acetyl pyridine and methylamine

The structure of the tetrahydrate of the nitroprusside salt of the tris-ligand-FeII complex of the Schiff base derived from 2-acetyl pyridine and methylamine has been established by x-ray diffraction methods. The cation has themer-configuration in this salt in the solid phase. Kinetic and spectroscopic, particularly1H n.m.r., results indicate that bothmer-andfac-isomers of this, and of related complexes, have to be considered in solution. Kinetics of base hydrolysis of the title cation, and its solvation, in MeOH-H2O mixtures are described and compared with those for other low-spin FeII-diimine complexes.