Synthesis and characterization of two complexes of glycine with lanthanum hexacyanoferrate(III) and hexacyanocobaltate(III)

The synthesis and analytical characterization of two new glycine complexes, La[Fe(CN)₆]3Gly · 2H₂O and La[Co(CN)₆]3Gly · 2H₂O, are reported. Both compounds are isostructural, with similar XRD patterns corresponding to a triclinic crystal structure with almost equal cell parameters. Mössbauer and IR spectra indicated a very asymmetrical environment for the hexacyano anion. Not all CN ligands are coordinated to the lanthanum cation, which is also attached to glycine molecules in the zwitterion form and to one of the water molecules. The second water molecule is labile and does not affect the Mössbauer spectra of the iron cation.