Selectivity for La3+ ion by synthesized 4-((5-methylfuran-2-yl) methylene)hydrazono)methyl)phenol receptor and its spectral analysis

The functionalized molecules with specific molecular sites appear to be a promising approach for detection of cation in UV-visible and fluorescence spectroscopy. The synthesized receptor 4-((5-methylfuran-2-yl)methylene) hydrazono)methyl)phenol MFMHMP was found selective for La3+ among Ag+, K+, Na+, Be2+, Mg2+, Ca2+, Eu3+, Al3+, La3+, Zr4+, Th4+, UO22+, Fe3+, Fe2+, Co3+, Ni2+, Cu2+, Zn2+, Cd2+ and Hg2+ metal ions used as their nitrates by UV-visible spectroscopy and fluorescence spectroscopy. The binding nature of MFMHMP with La3+ ion was analyzed by UV-visible, fluorescence, IR, mass spectroscopy and cyclic voltammetric studies. The stoichiometry was established to be 1:1 by Benesi-Hildebrand, mole-ratio method and method of continuous variation (Job's method) with good association affinity K = 6245 x 10(4)M(-1). Computational studies and Density functional theory (DFT) calculation gives the proof of electron transfer during excitation and emission. Binding energy of complex through Density Function Theory -62.387 kcal/mol has also indication of strong binding. The electron transfer energy of Higher occupied molecular orbital (HOMO) to Lower unoccupied molecular orbital (LUMO) is about 4.662 eV for MFMHMP+La3+ Complex. Among that all transitions HOMO -> LUMO + 8 and HOMO -> LUMO + 9 play a key role for the blue shift transition during complexation. (C) 2018 Elsevier B.V. All rights reserved.