Ferrocene-modified pyrimidinyl acyl-thiourea derivatives: Synthesis, structures and electrochemistry

Abstract

Two ferrocene-modified pyrimidinyl acyl-thiourea derivatives, N-ferrocenoyl- N′-(2-pyrimidinyl) thiourea 1 and N-ferrocenoyl- N′-(5-pyrimidinyl) thiourea 2 were prepared from the reactions of ferrocenoyl isothiocyanate with 2-aminopyrimidine or 5-aminopyrimidine, respectively. Both of the new compounds were characterized by 1H NMR, 13C NMR, IR, elemental analyses and single-crystal X-ray diffraction. Comparing with ferrocene, compounds 1 and 2 show red-shift in the absorption peaks and increasing anodic peak potentials ( E pa ) values in the cyclic voltammetry studies. Furthermore, the electrochemical data of compounds 1 and 2 correspondingly exhibit one-electron quasi-reversible and reversible electrochemical redox behaviors. In the solid-state, compound 1 forms a ladder-like assembly by hydrogen-bonding, whereas, compound 2 is assembled into two-dimensional network structure through hydrogen-bonding and unusual intermolecular O⋯π interactions between O-atoms of the carbonyl units and the cyclopentadienyl rings.