The non-stoichiometry of tetracyanocomplexes

Tetracyanocomplexes can be non-stoichiometric in three different ways: 1. The preparation of complexes such as M(NH₃)₂M'(CN)₄.nG and M(en)_m H'(CN)₄.nG can result in a non-stoichiometric product i.e. n is non-integer (refs. 1 and 2). 2. Heating a fully stoichiometric compound such as M(NH₃)₂M'(CN)₄.2G, can result in the loss of some of the guest molecules (ref. 3). 3. A stoichiometric or non-stoichiometric compound can absorb an aromatic molecule of the appropriate size (refs. 4–6) when heated in the presence of the molecule.