TEMPERATURE EFFECT IN SYNTHESIS OF FE(ATRZ)3SO4 COMPLEX COMPOUND

• Main Author: Vanessa, Maura
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/75385
• Institution: Institut Teknologi Bandung

Fe(Atrz)3SO4 complex is stable at room temperature. The color of the complex is purple and diamagnetic, but when the complex is heated it turns white and paramagnetic. The Fe(II) ion in the complex has d? outer electron configuration so it can form into two spin states, which are low spin (LS) with t2g? configuration and high spin (HS) with t2g?eg² configuration. The LS ? HS transition in this complex occurs reversibly when the complex is heated and cooled. It’s very simple to gain this complex, by reacting FeSO4.7H2O salt in demineralized water solvent and Atrz (4-amino-1,2,4-triazole) ligand in methanol solvent. In this research, the synthesis of the complex was carried out at three temperature variations, which at 70°C, 26°C, and -10°C to see the temperature effect on the synthesis of the complex. At 70°C, the complex suspension is white which indicates a high spin state, while at 26oC and -10oC the complex suspension is purple which indicates a low spin state. But after the products were dried, all of them turned a purple colour. The EDS (Energy Dispersive Spectroscopy) data shows that the Fe : C ratio is 1:6 which proves the existence of 3 Atrz ligands that coordinated to the Fe(II) ion. FTIR (Fourier Transform InfraRed) data proves that the existence of coordinated Atrz ligands to Fe(II) ion is at 618 Cm-1 . The purple colour of this complex is indicated by the absorption peak at a wavelength of 535 nm, which is green and produces purple as the complementary colour. X-ray diffraction data shows that this complex has a fairly high crystallinity. At room temperature, the effective magnetic moment value of this complex is 1,94 BM which indicates that 90% of this complex fraction is in a low spin state. The purple colour of this complex turns white when heated to 87oC and when cooled to room temperature, it turns purple at 39oC. This observation shows that the SCO (Spin Cross Over) phenomena in Fe(Atrz)3SO4 complex is above room temperature with hysteresis effects