Research focus

Scientific research involves template and non-template synthesis, physicochemical and structural characterization of new transition metal coordination compounds with different classes of commercial, non-commercial, and newly synthesized O-, N-, S- Se-binding organic ligands of different denticity, as well as the design of porous materials, such as metal–organic cross-linked structures MOFs (metal–organic frameworks), and generally coordination polymers of different periodicity. Predominating ligands are Schiff bases of bifunctional carbonyl compounds (salicylaldehyde, pyridoxal, 2-hydroxy-1-naphthaldehyde, 2-acetylpyridine, 2-(diphenylphosphino)benzaldehyde, diketones, etc.) and amines (semi-, thiosemi-, selenosemi-, and isothiosemicarbazide, aminoguanidine etc.), as well as pyrazole derivatives.

The research aims to synthesize potentially applicable novel compounds. The accent is put on the investigation of biological activity or photoluminescence, and also the suitability of coordination polymers for selective adsorption and storage of CO₂. Special care is taken during synthetic procedure optimization to obtain a series of related compounds in the form of single crystals suitable for crystal structure determination utilizing single crystal X-ray crystallography. The comparison of physicochemical, biological, and other selected properties of structurally characterized compounds structure–property correlation are investigated to better understand key structural factors in the mechanism of selected activities.

Hitherto, crystal and molecular structures of a large number of coordination compounds were determined by single crystal X-ray crystallography, leading to the unequivocal determination of precise coordination formula, ligand coordination mode, metal coordination environment, as well as geometrical characterization of packing of structural units which is of prime importance for the understanding of compound’s properties. Particularly important results of structural analyses obtained so far are unusual coordination modes of the ligands, besides interesting and diverse structural characteristics, and coordination polyhedrons.

The research involves the use of the Cambridge Structural Database, which allows a detailed comparison of novel structural parameters with literature data, and determination of structural trends in studied classes of the compounds.

Novel ligands and ligand precursors are designed with an analogy to already known compounds exhibiting proven biological activity or some other interesting property. The influence of metal ion coordination on biological activity is studied. Also, the antioxidative, antimicrobial, and antiproliferative activity of selected compounds are studied. Furthermore, the impact on the reversal of multidrug resistance (MDR) is studied, pertaining to the possible application of the compounds as carriers of standard pharmaceuticals in resistant cell lines, which is one of the major problems in chemotherapy application. In accordance with the achievement of energy efficiency in terms of purification and storage of CO_2, the effectiveness of newly synthesized coordination polymers for the adsorption of this gas is being tested, as well as the possibility of renewability of the used adsorbent.

In cooperation with National Center For Scientific Research – Demokritos (Greece), a study of photoluminescence of the ligands and their metal complexes is investigated, pertaining to a possible application in OLED materials.

It should be emphasized that, besides experimental research, selected compounds are studied by DFT theoretical calculations, the results of which are compared to experimentally obtained data. This is extremely important for understanding structures, properties, and reactivities, which determines the possibility of further applications.