CHRIS25 - 14-10-2012 at 07:09
I have been reading about Chelates, amongst the many acids mentioned I am interested in only three for the photographic purpose at this moment:
Acetic, Oxalic and Citric. Citric was mentioned as an excellent chelate because it binds with the Iron2 after the light has broken down the Iron3 to
Iron two in the Potassium Ferricyanide and Ammonium Iron3 citrate process. What I am having difficulty finding information about is what, (at a not
too complex level please) is going on between citric acid and Iron, from amongst the complexity that is above my head I have gleaned that the citric
acid prevents a precipitation? or degradation? of the Iron2; and also, please could someone confirm if Acetic acid also acts as a chelate? I only
have found Oxalic and Citric.
sargent1015 - 14-10-2012 at 18:15
I'm pretty sure acetate ions cannot chelate due to the angle constraint. I'm currently in Inorganic Chem and I have only ever seen it behave as a
monodentate ligand.
Malonic acid is another chelating ligand, plus if you can get ethylenediamine, that works too.