[{"from": "human", "value": "Provide a description of this molecule. [Al][Branch1][C][Cl][Branch1][C][Cl][Cl]"}, {"from": "gpt", "value": "The molecule is a chloride of aluminum. It is probably the most commonly used Lewis acid and also one of the most powerful. It finds widespread application in the chemical industry as the classic catalyst for Friedel-Crafts reactions, both acylations and alkylations. It also finds use in polymerization and isomerization reactions of hydrocarbons. Aluminium chloride, often in the form of derivatives such as aluminium chlorohydrate, is a common component in antiperspirants at low concentrations. Aluminum is the most abundant metal in the earth's crust and is always found combined with other elements such as oxygen, silicon, and fluorine.  (L739, L740, L751)"}]