Hexakis(urea-O)iron Complex Salts as a Versatile Material Family: Overview of Their Properties and Applications

Kende Attila Béres; Zoltán Homonnay; László Kótai

doi:10.1021/acsomega.3c09635

Hexakis(urea-O)iron Complex Salts as a Versatile Material Family: Overview of Their Properties and Applications

ACS Omega. 2024 Mar 4;9(10):11148-11167. doi: 10.1021/acsomega.3c09635. eCollection 2024 Mar 12.

Authors

Kende Attila Béres^{1

2}, Zoltán Homonnay², László Kótai¹

Affiliations

¹ Institute of Materials and Environmental Chemistry, HUN-REN Research Centre for Natural Sciences, Magyar Tudósok krt. 2., H-1117 Budapest, Hungary.
² Institute of Chemistry, ELTE Eötvös Loránd University, Pázmány Péter s. 1/A, H-1117 Budapest, Hungary.

Abstract

Due to their Fe- and N-containing reactive urea ligand content, the hexakis(urea-O)iron(II) and hexakis(urea-O)iron(III) complexes were found to be versatile materials in various application fields of industry and environmental protection. In our present work, we have comprehensively reviewed the synthesis, structural and spectroscopic details, and thermal properties of hexakis(urea-O)iron(II) and hexakis(urea-O)iron(III) salts with different anions (NO₃^-, Cl^-, Br^- I^-, I₃^-, ClO₄^-, MnO₄^-, SO₄^2-, Cr₂O₇^2-, and S₂O₈^2-). We compared and evaluated the structural, spectroscopic (IR, Raman, UV-vis, Mössbauer, EPR, and X-ray), and thermogravimetric data. Based on the thermal behavior of these complexes, we evaluated the solid-phase quasi-intramolecular redox reactions of anions and urea ligands in these complexes and summarized the available information on the properties of the resulting simple and mixed iron-containing oxides. Furthermore, we give a complete overview of the application of these complexes as catalysts, reagents, absorbers, or agricultural raw materials.

Publication types

Review