Aluminum isopropoxide is also called “aluminum triisopropoxide”. Chemical formula Al[OCH(CH3)2]3. Molecular weight 204.23. White solid. The melting point is 119°C and the boiling point is 135°C (1333.28Pa). Soluble in ethanol, isopropyl alcohol, benzene, toluene, carbon tetrachloride and petroleum ether. Decomposes into isopropyl alcohol and aluminum hydroxide in water. It has the general properties of metal alkoxides and is volatile. It exists in trimer or tetramer form. After hydrolysis, the corresponding alcohol is obtained. It reacts with alcohol or ester to exchange the alkoxy group, and reacts with carboxylic acid to generate acyloxy group. Aluminum (metal carboxylate) can reduce carbonyl compounds to alcohols and react with β-diketones and β-keto acid esters to form metal chelates. This product is toxic, LD5011.3g/kg (oral administration to white mice).
physical properties
Aluminum isopropoxide is also called aluminum isopropoxide. White solid powder. Hygroscopic. Relative molecular mass 204.24. Relative density 1.035. Melting point 118℃. Boiling point: 135℃ (1.333×103Pa), 131℃ (0.999×103Pa), 125.5℃ (0.733×103Pa), 113℃ (0.333×103Pa), 106℃ (0.199×103Pa), 94℃ (0.0667×103Pa). Decomposes when exposed to water. Soluble in ethanol, isopropyl alcohol, benzene, toluene, chloroform, carbon tetrachloride and petroleum hydrocarbons.
use
Aluminum isopropoxide is mainly used as a raw material for dehydrating agents, coatings, and waterproofing agents; pharmaceutical raw materials; and catalysts for the Melwein-Poundorf reaction to make carbonyl compounds, aliphatic ketones, and aliphatic aldehydes. Reduction to alcohol; alcoholysis and transesterification catalysts in organic reactions; preparation of aluminum soap; synthesis of overbased oxides, chelates, and acrylates.
Preparation method
It is obtained by reacting anhydrous isopropyl alcohol with aluminum flakes in the presence of mercury chloride or aluminum trichloride catalyst, and then evaporating excess isopropyl alcohol. The newly prepared aluminum isopropoxide exists in the form of trimer or tetramer. Used as a selective reducing agent, it can reduce aliphatic or aromatic carbonyl groups to hydroxyl groups without affecting groups containing olefinic bonds, acetylenic bonds, nitro groups, acetals, carbon-halogen bonds, and nitrile groups in the molecule (see ” Mivin-Pondolf-Whelan reduction method”). Store airtight in a dry place.
Aluminum powder and isopropyl alcohol can be produced by heating and reacting with the catalyst aluminum trichloride (or mercury chloride).
It can be prepared by adding excess isopropanol to the benzene solution of aluminum trichloride and reacting at 6°C.
