ACTA FAC MED NAISS 2018;35(1):37-48

Original article

UDC: 546.732+547.458

DOI: 10.2478/afmnai-2018-0004

Spectroscopic Characterization of Cobalt (II) Complexes with Reduced Low-Molar Dextran Derivatives

Žarko Mitić¹, Goran M. Nikolić¹, Milorad Cakić², Sanja Mitić², Goran S. Nikolić², Stevo Najman¹

¹University of Niš, Faculty of Medicine, Niš, Serbia
²University of Niš, Faculty of Technology, Leskovac, Serbia

summary

The formation of Co(II) ion complexes with reduced low-molar dextran (RLMD, Mw 5000 g/mol) was studied at the pH range from 7.0 to 13.5. The cobalt content in synthesized Co(II)-RLMD complexes was ~3–12% (AAS) and it generally increases with pH. Co(II)-RLMD complexes were characterized by UV-Vis spectrophotometry and FTIR spectroscopy. UV-Vis data for synthesized complexes indicate tetragonally distorted Oh coordination of Co(II) ions with O atoms from ligand. The presence of IR bands at 765cm^-1 and 910cm^-1 in Co(II)-RLMD complexes indicates the existence of α(1→6)O-glycosidic bonds. The similarities in the γ(C–H) range of the IR spectra indicate that there is no difference in the conformation of the glucopyranose units in RLMD and Co(II)-RLMD complexes. The occurrence of water molecules in Co(II)-RLMD complexes was confirmed by FTIR spectroscopy of deuterated samples.

Key words: Co(II)-dextran, AAS, UV-Vis, FTIR