Structure, optical transition analysis and magnetic study of lanthanide based metal-organic framework: holmium bi-tartrate trihydrate

Abstract

Abstract This study presents the hydrothermal synthesis of holmium bi-tartrate trihydrate single crystals. The crystal structure and morphology were determined using single crystal x-ray analysis and field emission scanning electron microscopy, respectively. Fourier transform infrared spectroscopy was employed to identify the ligand phase. The thermal stability was assessed through differential scanning calorimetry. The effect of ligand on the incorporated paramagnetic center is discerned by reckoning the magnetic moment of the same. Judd-Ofelt theory was utilized to analyze optical transitions and calculate excited state properties. The complex exhibited violet and red emissions, attributed to ligand-based and metal-based luminescence , respectively. The absence of antenna effect was due to a significant energy gap between the resonance energy state, 5 S 2 of the Ho(III) ion and the triplet state of the coordinated tartrate ligand. The synthesized MOF's prolonged radiative lifetime holds promise for laser technologies and environmental monitoring applications.