Synthesis, crystal structure, spectral and electrochemical characterization, DNA binding and free radical scavenging studies of ferrocene-based thioureas

Thioureas are important building blocks in medicinal chemistry; ferrocenes as highly hydrophobic moieties induce very interesting qualities in medicinal compounds. In this article, we have synthesized four ferrocene incorporated N,N′-disubstituted benzoyl thioureas (3a–3d) with general formula C5H5-Fe-C5H4C6H4Cl-NH-CS-NH-CO-C6H4(H/CH3). Molecular structures of these compounds were characterized in solid and solution phases. In solution molecular structures were established by 1H and 13C NMR and cyclic voltammetry. In the solid state their structures were characterized by elemental analyses and FTIR spectroscopy. Two of the compounds (3a and 3d) had also been structurally determined by single crystal X-ray diffraction analysis. The electrochemical characterization showed a reversible process with one electron transfer from Fe(II) to Fe(III). The single crystal analysis showed strong intermolecular non-covalent interactions in these compounds. Molecular structures of these compounds were also studied by density functional theory (DFT) calculation . DFT studies showed good correlation between calculated parameters and experimental results of solution phase and solid state characterizations. Compounds 3a–3d were evaluated for DNA interaction and antioxidant activity. These compounds interact with DNA via electrostatic forces and liberate significant binding constants and energies. Antioxidant potential –CSNH and –CONH groups induce same level of free radical scavenging ability in these compounds.