Abstract In this comprehensive experiment, potassium ferrioxalate was prepared by ferric chloride and potassium oxalate as raw materials and its structure was characterized. The composition and ion charge of the complexes was measured. The electronic spectra and infrared spectra of the ligands and complexes were mainly studied. The magnetic distance, XRD crystal structure, and thermal stability of the complex were measured. The experimental results show that the composition of the complex is K3[Fe(C2O4)3]·3H2O with a yield of 90.0%. The value of the absorption peak of the electronic spectrum is in the range less than 350~400 nm, which is caused by the electronic transition from the ligand to the central ion. The infrared spectrum infers the presence of bidentate or chelated oxalate in the complex. The magnetic moment of the complex is 5.16 B.M.. The hybrid state of the central ion Fe3+ is sp3d2. And the complex is a high-spin outer-orbital complex with an octahedral structure. Through this experiment, students can understand the principles of complex preparation, composition determination and structural characterization, and be familiar with various modern testing techniques. It can stimulate students' interests in scientific research, and cultivate students” comprehensive experimental and innovative abilities.
DAI Xiao-Min, FENG Ling-Zhu, LI Jia-Xin. University Chemistry Comprehensive Experiment: Preparation and Structural Characterization of Potassium Ferrioxalate[J]. Chinese Journal of Chemical Education, 2021, 42(4): 56-61.
