Tetra-μ4-oxo-tris(2-propanol)tetrakis[tetrakis(2-propanolato)titanium]tetrabarium

Abstract

The title compound, [Ba4{/z3-OTi(C3H70)4}4(C3H7-OH)3], is a BaTiO3 molecular precursor. The structure is based on a Ban tetrahedral cluster with all faces capped by OTi(Oipr)4 groups. Two of the faces are symmetrically capped (three #2-0 atoms) and two are unsymmetrically capped (two /z2-O atoms and one ~3-O atom). CommentThe thermal transformation of organometallic compounds is of interest in the sol-gel production of ceramics. Two areas of current interest are the formation of ferroelectric ceramics, e.g. BaTiO3, and hightemperature superconductors, e.g. YBa2Cu3OT. Sol-gel

Structure, photochemistry and applications of metal-doped polyoxotitanium alkoxide cages

“…The series of cages 1 and 2 illustrate one important feature of these species, that different Ti : M cage stoichiometries can often be obtained for a given metal ion for the same RO-ligand (e.g., Co II , Fe II ), simply by altering the stoichiometry of the reactions of Ti(OR) 4 : MX w . In other cases, mixtures of cages with different, Ti : M ratios have [38][39][40][41][42][43][44] The best fit line (in red) has been drawn so that it tends to zero as the condensation number tends to zero and tends to 2.0 as the cage nuclearity tends to infinity.…”

“…These metal-doped polyoxotitanium (M-POT), of the form [Ti x O y (OR) z M n X m ] (M = the dopant metal ion; X = an inorganic anion), are of interest as well-defined models for the way in which metal ions are incorporated into bulk titania (but, unlike metal-doped titania, are amenable to single-crystal X-ray crystallography). [37][38][39][40][41][42][43][44] In addition, they are potential organicallysoluble redox catalysts for a range of organic transformations, and have been shown to be highly effective single source precursor materials for the deposition of metal-doped TiO 2 and metal titanates. [45][46][47] This short review focuses on M-POTs as a structural class, their electronic structures and their applications as singlesource materials for materials deposition (especially in respect to anti-pollution and water splitting).…”

“…Fig.2Graph of number of metal atoms (x + n) in structurally characterised M-POT cages [Ti x O y (OR) z M n X m ] vs. the modified condensation number (y/(x + n)) [38][39][40][41][42][43][44]. The best fit line (in red) has been drawn so that it tends to zero as the condensation number tends to zero and tends to 2.0 as the cage nuclearity tends to infinity.…”

A self-assembled octanuclear complex bearing the uncommon close-packed {Fe4Mn4(μ4-O)4(μ-O)4} molecular core

“…The presence of such additional bridges is essential for the com- octanuclear compounds with this MST show the same geometrical configuration (b1) (Fig. 3) is observed only in three Ti 4 Ba 4 crystal structures [23][24][25] and it is the most complex one since it is formed using 16 bridging atoms. Obviously, the formation of complexes with the same MST but with a different geometrical configuration, at the least (b2), is also possible.…”

“…The MST {M 8 (µ 4 -X) 4 (µ 3 -X) 2 (µ-X) 10 } (d) (Fig. 3) is observed only in three Ti 4 Ba 4 crystal structures [23][24][25] and it is the most complex one since it is formed using 16 bridging atoms. A determining role in the formation of such structures conceivably is the ability of Ti and Ba to show high coordination numbers, supported by the small size of coordinated isopropanol ligands.…”