Synthesis, characterization and electrochemical recognition of metal ions of three new ferrocenyl derivatives containing pyridyl moiety

TIAN Hong-ju(田洪菊), TANG Rui-ren(唐瑞仁), LI Shi-feng(李石凤), LUO Yi-ming(罗一鸣)

(School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China)

Abstract:Three new ferrocene (Fc) based receptors with pyridyl moiety, named methyl-6- ferrocenoylacetyl-2-pyridine carboxylate (FcL₁), 1,1′-(2,6-bispyridyl)bis-3-ferrocenyl-1,3-propanedione (FcL₂), ferrocenecarboxaldehyde-2,6-dipicolinoyhydrazone (FcL₃) were synthesized, and further characterized by elemental analysis, IR spectra, UV-Vis spectra, ¹H and ¹³C NMR. The electrochemical properties and ion sensing properties of FcL₁, FcL₂ and FcL₃ were also investigated by means of cyclic voltammetry in ethanol solution with 0.1 mol/L LiClO₄ as the supporting electrolyte. The E⁰ values of the receptors increase with the scanning rate increasing at high scanning rate, and I_pa/I_pc approaches unity, indicating that the redox reaction is basically reversible. Their recognition performances to different metal cations such as Cd(II), Co(II), Cu(II), Hg(II), Mn(II), Ni(II), Zn(II) show that the FcL₁ is responsive to Cu(II) with the maximum electrochemical shift of the FcL₁ for Cu(II) of about 72.0 mV, whereas the FcL₂ is responsive to Cu(II) and Mn(II) with shift of 102 mV and 109 mV, respectively, and the FcL₃ is responsive to Hg(II) and Mn(II) with the shift of 53.0 mV and 54.0 mV, respectively. All the results show that these receptors may have potential applications in electrochemical sensor technology, material science, and molecular devices.

Key words:synthesis; receptor; characterization; electrochemical recognition