Aluminium phenolate is the metalloorganic compound with the formula [Al(OC6H5)3]n. It is a white solid. 27AlNMR studies suggest that aluminium phenolate exists in benzene solution as a mixture of dimer and trimer.[2] The compound is can be prepared by the reaction of elemental aluminium with phenol:[3]
Al + 3 HOC6H5 → Al(OC6H5)3 + 1.5 H2
The compound is used as a catalyst for the alkylation of phenols with various alkenes. For example, the ethylphenols are generated commercially by treating phenol with ethylene in the presence of a catalytic amount of aluminium phenolate.[4]
^Kolka, Alfred J.; Napolitano, John P.; Filbey, Allen H.; Ecke, George G. (1957). "The ortho-Alkylation of Phenols". The Journal of Organic Chemistry. 22 (6): 644. doi:10.1021/jo01357a014. The aluminum phenoxide catalyst was prepared by adding 4.5 g. (1⁄6 formula wt.) of aluminum turnings in small amounts and with vigorous stirring to 300 g. of phenol at 165° under a nitrogen atmosphere.
^Fiege, Helmut; Voges, Heinz-Werner; Hamamoto, Toshikazu; Umemura, Sumio; Iwata, Tadao; Miki, Hisaya; Fujita, Yasuhiro; Buysch, Hans-Josef; Garbe, Dorothea; Paulus, Wilfried (2000). "Phenol Derivatives". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. p. 533. doi:10.1002/14356007.a19_313. ISBN3527306730. 2‑Ethylphenol and 2,6‑diethylphenol are produced industrially by ortho-alkylation of phenol with ethylene in high pressure autoclaves at 320‑340 °C and 20 MPa in the presence of 1‑2% aluminum phenolate.