Structural, Electronic, Thermodynamic and Nonlinear Optical Properties of a Novel Ce(III) Complex with Ferrocenyl Dithiophosphonate

Abstract

In this study, a novel cerium(III) complex featuring a ferrocenyl dithiophosphonate ligand was synthesized and comprehensively characterized using a range of spectroscopic and analytical techniques. The  synthetic  route  involves  the  esterification  of 2,4-diferrocenyl-1,3-dithiadiphosphetane disulfide (ferrocenyl Lawesson's reagent) with isopropyl alcohol, followed by conversion to its ammonium salt and subsequent complexation with Ce(NO₃)₃ · 6H₂O in tetrahydrofuran. The structure of the complex was elucidated using Fourier transform infrared spectroscopy, ¹H- and ³¹P-nuclear magnetic resonance spectroscopy, thermal analysis, and elemental analysis. Spectroscopic results indicated successful coordination of Ce(III) through the dithiophosphonate moieties. Quantum mechanical  calculations  at  the  density  functional  theory/Becke, 3-parameter, Lee–Yang–Parr level provided insight into the geometric, electronic, and thermodynamic properties of the Ce(III) complex. The total density of states and frontier molecular orbital analyses revealed an energy gap of ΔE = 9.042 eV of the singly occupied–lowest unoccupied molecular orbitals, indicating high electronic stability. Theoretical calculations highlighted the significant nonlinear optical properties of a Ce(III) complex, demonstrating its potential for enhanced nonlinear optical performance due to the synergistic effects of the ferrocenyl dithiophosphonate ligand and Ce(III) ion. Additionally, thermodynamic parameters such as zero-point energy, entropy, and heat capacity were calculated, confirming the structural stability and potential functional applications of the synthesized Ce(III) complex in photophysical or catalytic systems.