Abstract: | Black solid precursors obtained from reactions between MCl5 (M = Nb, Ta) and alkyllithiums, n‐butyllithium (nBuLi) and ethyllithium (EtLi), in tetrahydrofuran (THF) were heat treated under vacuum at 673–973 K to form nano‐sized particles (20–100 nm in diameter) of lithium niobate (LiNbO3) and lithium tantalate (LiTaO3). Stoichiometry of the reactants is critical and affects the phases of the products. Based on the volatile byproducts detected, a reaction pathway involving the activation of THF by alkyllithiums is proposed to be important for the formation of LiNbO3 and LiTaO3 precursors. |