Figuring Out monodentate, bidentate, etc

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Elena Chen 2E
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Joined: Wed Sep 30, 2020 10:09 pm

Figuring Out monodentate, bidentate, etc

Postby Elena Chen 2E » Sun Dec 06, 2020 7:14 pm

Hi, I still don't really understand what it means when a ligand is monodentate, bidentate, tridentate, etc. How do we determine the -dentate state of a ligand?

Lillian Ma 1I
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Re: Figuring Out monodentate, bidentate, etc

Postby Lillian Ma 1I » Sun Dec 06, 2020 7:20 pm

The -dentate state represents how many lone pair of electrons it can contribute to a metal atom. In order to calculate it, you would have to draw it out to see how many lone pairs are able to bind to one center metal atom and that would be the number for the prefix of the dentate state.

Megan Lu 3D
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Joined: Wed Sep 30, 2020 9:49 pm

Re: Figuring Out monodentate, bidentate, etc

Postby Megan Lu 3D » Sun Dec 06, 2020 7:23 pm

Hi! To my understanding, a monodentate ligand describes a ligand that binds at one site of a central metal atom, donating one electron pair. A bidentate would be a ligand that binds at two sites, donating two electron pairs, and so on. To determine what kind of dentate a ligand is, we can consider the number of lone pairs there are on different atoms after drawing a Lewis structure. For example, if the ligand has three lone pairs, each on different atoms, it could be a tridentate. Hope this helps!

IshanModiDis2L
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Re: Figuring Out monodentate, bidentate, etc

Postby IshanModiDis2L » Sun Dec 06, 2020 7:24 pm

Like mentioned above, The -dentate state represents how many lone pair of electrons it can give or how many bonds can be formed with a central atom. For instance, polydentates are ligands that can form more than one bond with the same central atom, whether it be two bonds (bidentate), three bonds (tridentate), four bonds, (tetradentate) and etc. Polydentates can also form chelates which are complexes with 1 or more polydentates attached to it.

Carolina 3E
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Re: Figuring Out monodentate, bidentate, etc

Postby Carolina 3E » Sun Dec 06, 2020 7:25 pm

A ligand is a species bound to the metal ion which means it can be an atom or a molecule. If a ligand is a molecule that has multiple sites with lone pairs and single bonds that allow it to rotate in a way where multiple sites can bind to the metal ion simultaneously, then it is polydentate.

Katherine_Douglas_1F
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Re: Figuring Out monodentate, bidentate, etc

Postby Katherine_Douglas_1F » Sun Dec 06, 2020 7:26 pm

It is essentially how many bonds the ligand can form with the atom. In the case of H20, it is monodentate because the O is the donor atom and there is just one Oxygen. In the case of CH2CH2, though, the donor atom is the Carbon and, since there are two, it is bidentate.


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