Structural characterisation of silica gel anchored, biomimetic, mixed-ligand Co(II)–amino acid complexes

In this work the syntheses of covalently grafted N-protected Co(II)-mixed amino acid (N-protected l-histidine and N-protected l-tyrosine) complexes onto a surface-modified silica gel are described. Conditions of the syntheses were varied and the obtained structures were studied by classical analytical (titration) as well as spectroscopic (infrared, atomic absorption) methods. It was found that the structures obtained and the coordinating groups substantially varied upon changing the conditions of the synthesis.