In chemistry, subhalide usually refers to inorganic compounds that have a low ratio of halide to metal, made possible by metal–metal bonding (or element–element bonding for nonmetals), sometimes extensive. Many compounds meet this definition.
The normal halide of boron is . Boron forms many subhalides: several, including ; also BF. Aluminium forms a variety of subhalides. For gallium, adducts of are known. Phosphorus subhalides include ,, and (structurally related to). For bismuth, the compound originally described as bismuth monochloride was later shown to consist of clusters and chloride anions. There are many tellurium subhalides, including , (X = Cl, Br, I), and two forms of TeI.[1]