Identifying monodentate ligands

[Connie Liang 3L]

Is there a way to identify which ligands are monodentate? For example, I know that monodentate ligands contribute one lone pair of electrons to the transition metal. However, are there cases in which there are two lone pairs available in a certain ligand that's considered monodentate but only one of these lone pairs bind? How can we tell in these cases?

[shevanti_kumar_1E]

Lets look at the example of water where O has two lone pairs but it still is mono dentate. Due to the orbital geometry of water only one lone pair can have the correct orientation to bond. Additionally, bidentate ligands most of the time require distinct lone pairs on distinct atoms.

[Sedge Greenlee]

As Shevanti stated, it is the orbital geometry that dictates how what lone pairs can and cannot bind the the transition metal. Essentially, inorder for multiple lone pairs to bind to the transition metals, they need to have a geometry that allows for the lone pairs to be oriented in the same general direction. Agood example of this is of course chelates.

[AlyssaMaynard1C]

Lets look at the example of water where O has two lone pairs but it still is mono dentate. Due to the orbital geometry of water only one lone pair can have the correct orientation to bond. Additionally, bidentate ligands most of the time require distinct lone pairs on distinct atoms.

Is there a list we should know for the final, so it's easy to identify monodentates vs bidentates easily?

[AndrewNguyen_2H]

It's more intuition. You'll have to look at the geometry specifically and see if two bonds can be formed. Usually, they have more intermediate atoms for more flexibility.

[Connie Liang 3L]

Understood, thanks for the replies everyone!