Homo- and heteroleptic lanthanide-iron alkoxides as precursors in materials synthesis

Bimetallic iron-lanthanide alkoxides were synthesized by reacting [Ln{N(SiMe₃)₂}₃] (Ln ?= ?Pr, Nd, Er) with [Fe₂(O^tBu)₆] in excess tert-butyl alcohol that triggered in-situ ligand exchange and Lewis acid-base interactions to form heterometallic compounds. Single crystal X-ray diffraction analyses of new compounds demonstrated that both Nd and Er containing compounds resulted in the formation of a hetero-bimetallic framework based on 1:1 Ln:Fe ratio, whereas higher Fe ratio (1:2) was observed when Pr was used as the rare earth metal, possibly due to its larger ionic radius (Pr(III): 0.99 ?Å). When the reaction was performed in the presence of chelating ligands (L: H-tfb-mea ?= ?N-(4,4,4-trifluorobut-1-en-3-on)-methoxyethyleneamine; H₂-tfb-en ?= ?N–N′-bis-(4,4,4-trifluorobut-1-en-3-on)-ethylenediamine), heteroleptic Ln-Fe derivatives were formed that were used in a representative case ([NdFe(L)(O^tBu)_m(HO^tBu)]) as efficient precursor to synthesize nanocrystalline NdFeO₃ ceramic.