<Dl> <Dd> (PdCl) + 2n CH CN → n PdCl (CH CN) </Dd> </Dl> <Dd> (PdCl) + 2n CH CN → n PdCl (CH CN) </Dd> <P> The tetrahedral tetrahalides of the first - row transition metals are prepared by addition of a quaternary ammonium chloride to the metal halide in a similar manner: </P> <Dl> <Dd> MCl + 2 Et NCl → (Et N) MCl (M = Mn, Fe, Co, Ni, Cu) </Dd> </Dl>

Combinations of metals and halides - like nacl - are known as