Methaneselenol

Methaneselenol (also known as methylselenol and selenomethane) is a organoselenium compound with the formula CH3SeH. It is the simplest selenium analog of methanol. Methaneselenol is a key intermediate in the metabolic processing of selenium in the body, and is a critical compound in the understanding of selenium biochemistry.

Structure and Bonding

Methaneselenol is a molecule with a tetrahedral geometry around the selenium atom. The Se-H bond length is 146 pm, and the C-Se bond length is 192 pm. The bond angles are close to the ideal tetrahedral angle of 109.5°.

Synthesis

Methaneselenol can be synthesized by the reaction of dimethyl diselenide with a reducing agent such as sodium borohydride. The reaction proceeds via the intermediate sodium selenide, which is then protonated to give methaneselenol.

Biological Importance

Methaneselenol is a key intermediate in the metabolic processing of selenium in the body. It is produced from selenomethionine and selenocysteine by the action of selenocysteine lyase. Methaneselenol is then further metabolized to give methylseleninic acid and dimethylselenide, which are excreted in the breath and urine.

Safety

Methaneselenol is a highly toxic and volatile compound. It is a strong reducing agent and can react violently with oxidizing agents. It is also a potent lachrymator, causing severe eye and respiratory irritation.