## Alphabetizing Ligands

Rachel Caprini 1E
Posts: 21
Joined: Wed Sep 21, 2016 2:59 pm

### Alphabetizing Ligands

The rule states that you should list your ligands in alphabetical order in the long name and write them in alphabetical order in the chemical formula, so why do some compounds ignore this rule (i.e., [Cr(F)3(I)(H2O)2], Li[Ni(CN)3(en)(NH3) and [FeCl3(H2O)3]-)?

vsyacoubian2A
Posts: 63
Joined: Fri Jul 22, 2016 3:00 am

### Re: Alphabetizing Ligands

I don't think there is a particular order for writing ligands in a chemical formula. Formulas don't follow the alphabetical rule.

Chem_Mod
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Joined: Thu Aug 04, 2011 1:53 pm
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### Re: Alphabetizing Ligands

The IUPAC rule is to write the ligands in alphabetical order unless certain ligands are being emphasized. For example, anionic ligands are sometimes put before neutral ones.

Tara_Hekmati_3B
Posts: 28
Joined: Wed Sep 21, 2016 2:59 pm

### Re: Alphabetizing Ligands

I understand this rule, but for ligands with names that don't match their formulas like ammine and ethylenediamine, do you put the coordination compound formula in alphabetical order based on the name of the ligand or it's formula?

Katherine_Zhuo_3B
Posts: 23
Joined: Wed Sep 21, 2016 2:57 pm

### Re: Alphabetizing Ligands

For the formula, as long as you put the transition metal first, the ligands can be put in any order following the metal.