Hydroxyaluminium(I), also known as Aluminium(I) hydroxide, is an inorganic chemical with molecular formula AlOH. It consists of aluminium in the +1 oxidation state paired with a single hydroxide. It has been detected as a molecular substance in the envelope of an oxygen-rich red supergiant star, a place where substances containing metals or hydroxides are thought to be rare.[1]
In the laboratory AlOH can be made by heating aluminium, so that it vapourises into low pressure hydrogen peroxide vapour.[2] Another method is to condense a mixture of aluminium vapour, hydrogen and oxygen with argon into a solid at 10K. Along with AlOH, there are also Al(OH)2, Al(OH)3, HAl(OH)2, cyc-AlO2 and AlOAl molecules formed.[3]
The bond lengths are, Al-O 1.682 Å, and for O-H 0.878 Å.[2] The rotational constants are B0=15,740.2476 MHz and D0=0.02481 MHz.[2]