I noticed some transition metals such as Co2+, Ni2+, Cu2+, Zn2+ will form complexes in 1M NaOH but when in 1M NH3, there is some interference and don't form give the same result. So far I've deduced that NH3 interferes by displacing OH2 and OH ligands and thus oxidises Co(II) to Co(III), and making insoluble Ni(II), Cu(II) and Zn(II) hexaqua complexes become soluble hexamine complexes. Is there anything wrong in saying this?
However for other transition metals such as Fe(II), Fe(III), and Mn(II); there is no interference by NH3 and I can't explain why these metals are not affected. Any leads?