Heterobimetallic peroxo-titanium(iv) nitrilotriacetate complexes as single source precursors for preparation of MTiO3 (M = Co, Ni and Zn)

Abstract

Three isostructural heterobimetallic nitrilotriacetatoperoxotitanate complexes of general formula [M(H₂O)₅]₂[Ti₂(O₂)₂O(nta)₂]·7H₂O [M = Co (1), Ni (2) and Zn (3)] have been isolated in pure crystals directly from the quaternary system of M²⁺–Ti(OC₄H₉)₄–H₂O₂–H₃nta (H₃nta = nitrilotriacetic acid) at pH = 4.0 and have been characterized by elemental analyses, IR, thermal analysis (TGA), and single-crystal X-ray diffraction. Single crystal X-ray analysis reveals that the titanium atom in these complexes features seven-fold-coordination, each surrounded by six oxygen atoms and one nitrogen atom. The divalent transition metal ions in these compounds are hexa coordinated, surrounded by five water molecules and one bridged carboxylato oxygen atom. The TGA and XRD results prove that complexes 1–3 undergo facile thermal decomposition to form pure CoTiO₃, NiTiO₃ and ZnTiO₃ at 700 °C respectively. The morphologies, microstructures, and crystallinity of the residues obtained after pyrolysis were characterized by transmission electron microscopy and powder X-ray diffraction.