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Cobalt(III) complexes derived from thio-and selenosemicarbazone ligands have been studied to elucidate the nature and consequences of S to Se substitution on their possible biological activity. Solid state structures of cobalt(III) complexes with bis-tridentate coordinated 2-quinolinecarboxaldehyde thio-and selenosemicarbazone were determined by single crystal X-ray diffraction analysis. The complexes were also characterized by spectroscopic methods and cyclic voltammetry. Electronic properties of the complexes were studied using DFT and TD-DFT methods. Finally, evident in vitro antioxidant activity of the complexes was demonstrated.

Cobalt(III) complexes derived from thio-and selenosemicarbazone ligands have been studied to elucidate the nature and consequences of S to Se substitution on their possible biological activity. Solid state structures of cobalt(III) complexes with bis-tridentate coordinated 2-quinolinecarboxaldehyde thio-and selenosemicarbazone were determined by single crystal X-ray diffraction analysis. The complexes were also characterized by spectroscopic methods and cyclic voltammetry. Electronic properties of the complexes were studied using DFT and TD-DFT methods. Finally, evident in vitro antioxidant activity of the complexes was demonstrated.

An approach to model the trans-influence using partial atomic charges derived from the molecular electrostatic potential by means of the restrained electrostatic potential (RESP) fitting method is exemplified on a series of halogenido-ammine octahedral chromium(III) complexes. RESP charges incorporated in the present vibrationally optimized consistent force field account for second-order phenomena, improve the modeling and assignment of skeletal vibrations, and reproduce the trends in frequency shifts along the F, Cl, Br, I series. In addition, a supplementary statistical analysis is given for the Cr-halogen bonds in the crystal structures from the CSD.

An approach to model the trans-influence using partial atomic charges derived from the molecular electrostatic potential by means of the restrained electrostatic potential (RESP) fitting method is exemplified on a series of halogenido-ammine octahedral chromium(III) complexes. RESP charges incorporated in the present vibrationally optimized consistent force field account for second-order phenomena, improve the modeling and assignment of skeletal vibrations, and reproduce the trends in frequency shifts along the F, Cl, Br, I series. In addition, a supplementary statistical analysis is given for the Cr-halogen bonds in the crystal structures from the CSD.

Molecular mechanics (MM) calculations to analyze the puckering of metalloporphyrins isolated and adsorbed on a graphite layer (0001) as a function of metal ion size and the peripheral substitution are presented. The Consistent Force Field (CFF) program was used with new parameters for metalloporphyrins, which included an out-of-plane bending function. Normal-coordinate structural decomposition (NSD) analysis was performed on the equilibrium structures obtained by the MM calculations. The conformers were also stereo-chemically characterized and compared with available experimental data and with conformers obtained in a previous MM study., Konzistentno polje sila (CFF) za molekulsko modeliranje metaloporfirina, koje uključuje novouvedenu out-of-plane funkciju, parametrizovano je na osnovu kristalnih struktura Ni(II)-porfirina, nikal(II)-mono-tercbutilporfirina, nikal(II)-di-tercbutilporfirina, nikal(II)-tetrafenilporfirina i nikal(II)-oktaetil-tetrafenilporfirina. Ono je upotrebljeno za proučavanje uticaja veličine centralnog metalnog jona, periferne supstitucije kao i uticaja prisutnog supstrata na konformacije porfirinskog jezgra kod okta- i tetrahalogeno-tetrafenilporfirina sa Ni(II) i Tb(III). Jedinstvene ravnotežne strukture, dobijene na osnovu molekulsko-mehaničkih proračuna velikog broja početnih struktura, pokazuju dobro slaganje sa kristalnim strukturama, kao i sa prethodno publikovanim rezultatima, ne samo u metričkim podacima, već i u načinu nabiranja porfirinskog jezgra. Metod normalne-koordinatne strukturne dekompozicije (NSD) omogućava da se na jednoznačan način opiše svaka optimizovana konformacija dobijena molekulsko-mehaničkim proračunima.