Electrochemical behavior and conversion to Fe₂O₃ nano particles of a neutral seven coordinated iron(III) complex with dipicolinic acid

Abstract

An iron complex of dipicolinic acid (dipicH₂), formulated as [Fe(dipic)(NO₃)(H₂O)₂]·2H₂O (1), was prepared and characterized. Cyclic voltammetric response of bare carbon paste electrode surface in 0.10 mol L⁻¹ phosphate buffer containing 1 at pH = 7 and at various scan rates (10–70 mVs⁻¹) was studied. The apparent charge transfer rate constant, ks, and transfer coefficient, a, for electron transfer [Fe(dipic)(NO₃)(H₂O)₂]·2H₂O were calculated as 1/1 ± 0.10 s⁻¹ and 0.49, respectively. Thermal decomposition of 1 in the presence of polyethylene glycol led to the formation of Fe₂O₃.

Keywords:

• Electrochemical behavior
• dipicolinic acid
• seven-coordinated iron(III)
• crystal structure
• nano Fe₂O₃

Acknowledgments

This research was supported by Science and Research Branch, Islamic Azad University. The crystallographic part was supported by the project 15-12719S of the Czech Science Foundation using instruments of the ASTRA lab established within the Operation program Prague Competitiveness - project CZ.2.16/3.1.00/24510.