guanidiniumchlorid

Guanidinium chloride, also called guanidinium hydrochloride, is a salt composed of the guanidinium cation [C(NH2)3]+ and the chloride anion Cl−. It crystallizes as a white, hygroscopic solid and is highly soluble in water. The compound is typically prepared by reacting guanidine with hydrochloric acid.

In aqueous solution the guanidinium cation is the conjugate acid of guanidine; as the salt of a weak base with a strong acid, the solution is typically mildly acidic. The salt is stable under ordinary conditions but can decompose on strong heating. It is stored in a dry place away from light and oxidizers.

Guanidinium chloride has several practical uses in chemistry and biochemistry. It is widely used as a denaturant for proteins at high concentrations because the guanidinium ion disrupts hydrogen bonding and hydrophobic interactions, promoting protein unfolding. It can also serve as a source of guanidinium ions in buffers and as a reagent in organic synthesis for introducing guanidine functionality or in various extraction and purification protocols.

Safety: Guanidinium chloride is corrosive and can be harmful if swallowed or inhaled; it may irritate skin and eyes. Appropriate personal protective equipment should be used, and work should be conducted in a well-ventilated area. Store sealed in a dry location away from oxidizers, and rinse thoroughly with water if contact occurs.