Synthesis, spectroscopic (FT-IR, UV–visible) study, and HOMO-LUMO analysis of adenosine triphosphate (ATP) doped trivalent terbium

Abstract

The lanthanides and nucleotides can form attractive organic coordination polymers. The ligand complex adenosine-5′-triphosphate (ATP) with metal Terbium (Tb3+) has been successfully synthesized. The complexes were characterized by FT-IR spectroscopy and UV–vis spectroscopy. The results showed that the metal Tb(III) coordinates with adenosine-5′-triphosphate (ATP) through the electrons in the oxygen atom from the phosphate group and the electrons on the nitrogen atom in the adenine ring. FT-IR proved the existence of ATP-Tb with a vibration band of 908 cm−1 and 349 cm−1 to form a P-O-Tb bond and a vibration band of 1635 cm−1 showing the coordination of Nitrogen N1 and N7 atoms as electron donors in terbium metal. The absorption bands at λ = 318.5 nm and 485.5 nm represent the electronic transitions of 7F6 → 5H7 and 7F5 → 5D4 and the redshift occurs after the addition of Tb3+ to ATP with the mole ratio of ATP: Tb [1: 2]. The direct band gap obtained from 4.19 to 4.7 eV as a wide band gap semiconductor material and the indirect band gap obtained from the 5.5–6.0 eV range is an insulator. The HOMO-LUMO energy band gap of the ATP-Tb complex is 3.721 eV. This value is similar to that obtained from experiments using the UV–visible spectrum. Calculations of band gap energies, interactions, and spectral properties of complex compounds can provide the basis for the design of wide band gap semiconductor materials for rare earth complexes with organic ligands. The electronic properties of ATP-Tb have been calculated Ionization potential (I), electron affinity (A), chemical hardness (η), chemical softness (ζ), chemical potential (μ), electronegativity (Х), dan electrophilicity index (ω).