Asymmetrically substituted triazenes as poor electron donor ligands in the precursor chemistry of iron(II) for iron-based metallic and intermetallic nanocrystals

摘要

Triazene ligands are introduced, for the first time, in the precursor chemistry for their ability to afford oxygen-free molecular precursors of Fe-0 nanoparticles. For this purpose, we synthesized new asymmetric triazene ligands t-BuNvN-NHR (R = Et, i-Pr, n-Bu) featuring different alkyl substituents at 1,3-N centers, as well as a symmetric ligand t-BuNvN-NHt-Bu and used them to develop novel heteroleptic monomeric FeII triazenide derivatives [Fe(t-BuN3R)(2)(TMEDA)] (where TMEDA = tetramethylethylenediamine). A range of physico-chemical studies such as FT-IR, TG-DTA, H-1 & C-13 NMR, mass spectrometry, single crystal X-ray structure analysis, cyclic voltammetry and Mssbauer spectroscopy were used to characterize these newly synthesized ligands and Fe-II derivatives. One representative derivative [Fe(tBuN(3)Et)(2)(TMEDA)] was evaluated as a precursor for the synthesis of metallic Fe-0 and intermetallic Al13Fe4 nanoparticles by the chemical solution deposition method.