TRIS-4-AMINO-1,2,4-TRIAZOLE IRON (II) COMPLEX COMPOUNDS WITH OXOBELERANG ANION

• Main Author: Y. Simorangkir, Anris
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/67653
• Institution: Institut Teknologi Bandung

Spin Cross Over (SCO) phemomenon describes a spin state transition of a complex compound due to external pertubation such as temperature, pressure, and light. The spin transition reversibly from high spin state (HS) to a low spin state (LS) has the potential to be utilized as memory and sensor materials. One of the compound that shows this phenomenon is [Fe(Atrz)3]SO4 (Atrz = 4-amino-1,2,4-triazole). This complex exhibit hysteresis effect with ????? =27???? (???????? ? =346 ???? and ????????? =319 ????) and a reversible purple ? white color change. However, iron(II)-4-amino-1,2,4-triazol with other oxosulfur such as anion (thiosulfate (S2O32-), metabisulfite (S2O52-), and tetrathionate (S4O62-)) have not been reported. In this study, these complex compounds have been successfully synthesized. Fe(Atrz)3S2O3 is white powder and has a paramagnetic characteristic with magnetic momen value of 4,8 – 5,1 BM. This compound changed to a brownish yellow color after three days. The color changed was not accompanied by a significant change in elemental mass percentage. Through SEM imaging, Fe(Atrz)3S2O3 has a cubical shape with 2,3 ????m side length. Meanwhile, Fe(Atrz)3S2O5 compound is a paramagnetic purple-powder which is a mixture of low spin (LS) and high spin (HS) state. This compound has rod-like shape with particle length of 1,1 ????m. These two compounds are thermally unstable which is indicated by mass loss start from 30?. On a contratory, Fe(Atrz)3S4O6 is a stable and paramagnetic white powder compound with magnetic moment value about 5 BM. This complex changes its color to purple while being cooled. Through TGA analysis, Fe(Atrz)3S4O6 does not contain any water molecule. DSC test shows two different transitions in the thermogram which describe the spin state change. In the cooling process, the HS to LS transition occurs at ????????? =282,7 ???? (????????=?16 ???????? ?????????????1,????????=?57 ???? ?????????????1?????1) and reverse spin state transition, in heating process, occurs at ????????? =296,1 ???? (????????=12 ???????? ?????????????1,????????=39 ???? ?????????????1?????1). These entalphy and entropy values are in the same range with other iron(II) SCO complex compounds. Therefore, Fe(Atrz)3S4O6 has the potential to be developed as advanced materials.