Monodentate vs Bidentate etc. [ENDORSED]

[kaitlindaugherty3L]

How do you tell if something is monodentate, bidentate, or some other form of dentate? I asked one of the UA's and they said that we should memorize which ones are bidentate, and other forms cause the others will just be monodenate. However, I cannot find the information on which ligands are which dentates.

[MichelleT_1L]

I am also wondering about this. In my Peer Review Session, the UA mentioned something about the number of bonds that the central atom can make being the indicator?

[Christine Wastila 1H]

Monodentate ligands only have one electron donor atom that binds with the central atom/ion. Thus, they are only attached at one point. Polydentate ligands are able to attach to the central atom/ion multiple times due to the presence of multiple electron donor atoms. In many cases, ligands are monodentate. From what I've gathered through the homework, common bidentate ligands include ethylenediamine (en) and the oxalate ion. A common polydentate ligand would be EDTA.

[Sandhya Rajkumar 1C]

I saw a chart in the textbook that specified some of the polydentate ligands, it's in chapter 17, table 17.4.

[Kaelie Blanes-Ronda 2L]

Monodentate can be translated as "one tooth," referring to the ligand binding to the center through only one atom. Bidentate ligands have two donor atoms which allow them to bind to a central metal atom or ion at two points. Polydentate ligands range in the number of atoms used to bond to a central metal atom or ion.

[Veronica Rasmusen 2B]

Monodentate refers to a ligand that bonds to the central transition metal at one point. A bidentate is a ligand that can bond at two points to the transition metal. So basically you would look for how many atoms in the ligand are electron donors and could make bonds to the central TM.

[Alex Nechaev 1I]

At the TA review session on Monday, they mentioned that the best way to determine whether a ligand is a polydentate is to try to draw the Lewis structure. This way, you can actually see the bonding sites in order to know.

[Adrian Lim 1G]

Also, to look at what kind of dentate it would be, you could look for nitrogen. Usually, nitrogen would have a lone pair of elections that would want to form a bond. Also, you could look for atoms that have a negative charge, for those are the ones that would want to form bonds. Otherwise, it would be more convenient to draw the Lewis structure.