Mercuric amidochloride is an inorganic compound with the formula HgNH2Cl. It consists of a zig-zag 1-dimensional polymer (HgNH2)n with chloride counterions. It arises from the reaction of ammonia and mercuric chloride. Addition of base converts it into "Millon's base," which has the formula [Hg2N]OH(H2O)x. A variety of related amido and nitrido materials with chloride, bromide, and hydroxide are known.