TetrametallicD₃-Symmetric Alkoxide Molecules Containing Aluminum

Abstract

A new series of aluminum alkoxide molecules of formula [Al{(µ-OEt) 2 AlR 2 } 3 ], where R ) Me (1), Et (2), i Bu (3), and [Al{(µ-OEt) 2 GaR 2 } 3 ], where R ) Me (4) and Et (5), have been synthesized and fully characterized. In pure form 1, 2, and 4 are crystalline solids. However, in the presence of a small amount of solvent or impurity all of the compounds exist as oils. They were characterized by 1 H NMR, IR, elemental analysis, mp, and single-crystal X-ray diffractometry for compounds 1, 2, and 4.

Ambient‐Condition nano‐Alumina Formation Through Molecular Control

“…1.9 Å ) than for the four-coordinate aluminum atoms (av. 1.8 Å ); this is expected as the atomic radii increase with an increase in coordination number [15,16]. The SiϪO bond distances, ranging from 1.601(5) Å to 1.617(4) Å , are comparable to those observed in several related compounds [20,21].…”

“…Preparation of [Al{µ-OEt) 2 where R ϭ Me (1), Et and i Bu have been previously synthesized and fully characterized in our laboratory [15,16]. To explore the stability of the Al 4 O 6 core, 1 was combined with 6 equivalents of tri(phenyl)silanol (Scheme 1).…”

“…Compounds 2 and 3 were characterized by 1 H NMR, 27 Al NMR, elemental analysis, IR and mass spectrometry (MALDI). The mass spectrum (EI, positive) of compound 3 contains two important peaks: [Al{µ-OEt) 2 AlR 2 } 3 ] (R ϭ Me (1), Et) which also exhibit a tetrametallic tri-diamond structural motif [15,16]. Compound 2 contains one central six-coordinate aluminum and three four-coordinate aluminum atoms connected to the central atom through six bridging oxygen atoms.…”

“…To a suspension of Ph 3 SiOH (3.540 g, 12.8 mmol) in toluene (25 mL) at room temperature was added a toluene solution (15 mL) of [Al{(µ-OEt) 2 AlMe 2 } 3 ] (1.000 g, 2.13 mmol) (prepared according to the literature) [15]. After the solution was stirred for 3 days, a white precipitate formed which was isolated by filtration.…”

“…Recently, our group reported a series of tetrametallic molecules [Al{µ-OEt) 2 AlR 2 } 3 ] (R ϭ Me (1), Et, i Bu) with a tri-diamond or "Mitsubishi" structure [15,16]. These molecules were designed for creating corrosion resistant coatings on metal substrates [17].…”