 Basic hydroxides, whether solids or in solution, are stored in airtight plastic containers.The hydroxide ion can function as a typical electron-pair donor ligand, forming such complexes as tetrahydroxoaluminate/tetrahydroxidoaluminate [Al(OH)4]−.It is also often found in mixed-ligand complexes of the type [ML"x"(OH)"y"]"z"+, where L is a ligand.