Room temperature perovskite production from bimetallic alkoxides by ketone assisted oxo supplementation (KAOS)

Abstract

Barium titanate has been prepared at room temperature from a well-characterized crystalline barium titanium oxo alkoxide by reaction with acetone. An aldol condensation apparently supplies oxygen to condensing oxo alkoxide clusters. Transmission electron microscopy confirms that the crystallites so formed are dense and perfect with an average size of approximately 85 Å. Characterization of reactants and products provides a tentative understanding of structural evolution and the intermediates of the transformation. Crystalline SrTiO3 and BaZrO3 were also formed at room temperature by this same method.

Organic Reaction Pathways in the Nonaqueous Synthesis of Metal Oxide Nanoparticles

“…[169] Also the preparation of BaTiO 3 nanocrystals 6-15 nm in size was achieved at room temperature by the long-time stirring of solutions of a pre-synthesized mixed barium/titanium oxoalkoxide in acetone. [170] In some cases, a side mechanism closely related to the Meerwein-Ponndorf-Verley reaction was observed, as first described to occur upon heating of aluminum alkoxides in acetone. [229][230][231] This pathway has also been observed as side reaction in the formation of BaTiO 3 in cyclohexanone, [170] in which the ligand is oxidized to the respective ketone through a hydride transfer from the alkoxide ligand to a coordinated solvent molecule, whilst the solvent is reduced to an alkoxy group.…”

“…[170] In some cases, a side mechanism closely related to the Meerwein-Ponndorf-Verley reaction was observed, as first described to occur upon heating of aluminum alkoxides in acetone. [229][230][231] This pathway has also been observed as side reaction in the formation of BaTiO 3 in cyclohexanone, [170] in which the ligand is oxidized to the respective ketone through a hydride transfer from the alkoxide ligand to a coordinated solvent molecule, whilst the solvent is reduced to an alkoxy group. In this particular case starting from A C H T U N G T R E N N U N G TiA C H T U N G T R E N N U N G (OiPr) 4 in cyclohexanone, acetone and cyclohexanol are formed.…”

“…[169] Crystalline BaTiO 3 was obtained by transformation of the bimetallic alkoxide complex [(BaTiO) 4 16 ]·3 iPrOH in acetone under stirring at room temperature for 21 days. [170] BaTiO 3 was also synthesized in acetophenone starting from metallic barium and titanium isopropoxide. [171] In comparison to BaTiO 3 prepared by the benzyl alcohol route, these nanoparticles are larger, namely in the size range of 10-15 nm.…”

Fabrication of high concentration barium titanate/polyvinylpyrrolidone nano-composite thin films and their dielectric properties

“…29 and 338 besides the main peaks for the method B, they could not be assigned to other BT phases. The crystal sizes of the BT particles, which were calculated with the Scherrer equation from the (2 0 0) peak, were 6.3 nm for the method A and 7.3 nm for the method B. Gaskins and Lannutti prepared perovskite BT particles with particle sizes of 6-15 nm and a crystal size of 8.5 nm at room temperature starting from barium titanium oxo-isopropoxide [20]. The particle size and crystal size in the present paper were comparable to those in Gaskins and Lannutti' work.…”

Flexo printed sol-gel derived vanadium oxide films as an interfacial hole-transporting layer for organic solar cells

“…This methodology, aldolate formation, has already been utilized for some perovskites. 23 Interestingly in that study ketones were used to facilitate the alkoxide to oxide conversion.…”