Synthesis, Spectroscopic Characterization and DFT Calculations of a Novel Lanthanum Complex of Ferrocenyl Dithiophosphonate

Abstract

In this study, a novel lanthanum complex based on ferrocenyl (Fc) dithiophosphonate was synthesized and characterized, and quantum   chemical   calculations   were   performed.  The   reaction  of     2,4-diferrocenyl-1,3-dithiadiphosphetane      disulfide     dimer  [FcP(µ-S)S]₂ (ferrocenyl Lawesson reagent: FcLR) with iso-propyl alcohol (ⁱPr) gave the O-alkyl ester ([FcPS(OR)SH], R = ⁱPr), and the ester was converted to its ammonium salt, [NH₄L] (1), where L was the ferrocenyl phosphonodithioate anion. A novel lanthanum complex was prepared by the reaction  of  [NH₄L] with the salt  of  La(NO₃)₃  ·  6H₂O   in   tetrahydrofuran   solvent,   thus   giving   [[LaL₂]NO₃ · 4H₂O] (2). The synthesized compounds were characterized using (¹H, ³¹P) nuclear magnetic resonance, Fourier transform infrared, thermal, and elemental analysis. Density functional calculations of both compounds were performed in order to obtain valuable information about the electronic structures, properties, and reactivity of the synthesized molecules.  Optimized  geometries, molecular   electrostatic   potential   surface,  and  HOMO–LUMO orbitals of the compounds 1 and 2 were calculated with a 6-311G(d,p) basis set using density functional theory and B3LYP functional. LanL2DZ with an effective core potential for the Fe and La atoms was used.