using bis, tris, tetrakis

[Silvia Huang 3D]

Can someone please explain when to use bis, tris and tetrakis and give a few examples.
I thought you would only use it if the ligand's name had di etc in it, for example 2dien ligands would be biethlyenetriaminetetraacetato??

HW Q11.31
sodium bisoxalato (diaqua) ferrate(III)
Why did the solution put bis in front of oxalate?? and Why is diaqua in brackets?

Thank you very much!

[anne_kleinaitis_3B]

Oxalato is bidentate which is a type of polydentate; if a ligand is polydentate, then bis, tris, tetrakis, etc are used.

[EPerez1B]

When naming coordination compounds, prefixes mono-. di-, tri-, tetra-, penta-, and hexa- are used to indicate the number of ligands present. If a ligand already has a prefix or is polydentate, the prefixes bis-, tris-, or tetrakis- are used.

[Anne Cam 3A]

You would use bis-, tris-, and tetrakis- when the ligand already has prefixes like di- and tri- in its name, or if you know for sure it is polydentate (includes bidentate, tridentate, hexadentate or generally anything over monodentate).

If you were naming 2 dien ligands, you would write bis(dien) or bis-diethylenetriamine, but the shorter form would probably be easier. If you had three en ligands, you would write tris(en) or tris-ethylenediamine. If you had 2 carbonate ligands that are bidentate (though they are usually monodentate) you would write biscarbonato.

Oxalate is bidentate, even though it doesn't have a prefix like di- in it, so you would still add bis- as a prefix. Diaqua was probably put in parentheses to distinguish it from the other ligands.

[Vanessa A 3F]

The complex ligands that are in our course reader are oxalato, (en), and (dien). These and other complex ones are the only ligands you would need to use bis, tris, and tetrakis for. For all other ligands, use the usual prefixes of bi, tri, tetra.