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 (<b>3a–3d</b>) 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 (<b>3a</b> and <b>3d</b>) 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 <b>3a–3d</b> 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 –CSN<b><i>H</i></b> and –CON<b><i>H</i></b> groups induce same level of free radical scavenging ability in these compounds.