Irving–Williams series

The Irving–Williams series refers to the relative stabilities of complexes formed by <a href="/facts/Transition_metal/0slGWoLQ">transition metals</a>. In 1953 <a href="/facts/Harry_Irving_(chemist)/3RC6nn17">Harry Irving</a> and <a href="/facts/Robert_Williams_(English_chemist)/ARnn6dqW">Robert Williams</a> observed that the <a href="/facts/Stability_constants_of_complexes/7b2VkVb2">stability</a> of complexes formed by <a href="/facts/Divalent/ck7cHByj">divalent</a> first-row transition metal <a href="/facts/Ion/3bePpDna">ions</a> generally increase across the period to a maximum stability at copper: Mn(II) < Fe(II) < Co(II) < Ni(II) < Cu(II) > Zn(II).
Specifically, the Irving–Williams series refers to the exchange of <a href="/facts/Transition_metal_aquo_complex/eKudHVQy">aqua (H2O) ligands</a> for any other <a href="/facts/Ligand/6etB3qeW">ligand</a> (L) within a metal complex. In other words, the Irving–Williams series is almost exclusively independent of the nature of the incoming ligand, L.
The main application of the series is to empirically suggest an order of stability within first row transition metal complexes (where the transition metal is in oxidation state II).
Another application of the Irving–Williams series is to use it as a correlation "ruler" in comparing the first stability constant for replacement of water in the aqueous ion by a ligand.

Irving–Williams series open-in-new

Irving–Williams series