Uranyl hydroxide
Uranyl hydroxide is a hydroxide of uranium with the chemical formula UO(OH) in the monomeric form and (UO)(OH) in the dimeric; both forms may exist in normal aqueous media. Uranyl hydroxide hydrate is precipitated as a colloidal yellowcake from oxidized uranium liquors near neutral pH.
Osmium tetroxide
Osmium(VIII) oxide forms monoclinic crystals. It has a characteristic acrid chlorine-like odor. The element name osmium is derived from "osme", Greek for "odor". OsO is volatile: it sublimes at room temperature. It is soluble in a wide range of organic solvents. It is also moderately soluble in water, with which it reacts reversibly to form osmic acid (see below). "Pure" osmium(VIII) oxide is probably colourless and it has been suggested that its yellow hue is due to osmium dioxide (OsO) impurities. The osmium tetroxide molecule is tetrahedral and therefore non-polar. This nonpolarity helps OsO penetrate charged cell membranes. OsO is 518 times more soluble in carbon tetrachloride than in water.