Identifying monodentate ligands

Moderators: Chem_Mod, Chem_Admin

Connie Liang 3L
Posts: 59
Joined: Wed Sep 30, 2020 10:00 pm
Been upvoted: 1 time

Identifying monodentate ligands

Postby Connie Liang 3L » Sun Dec 06, 2020 1:51 pm

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
Posts: 90
Joined: Wed Sep 30, 2020 9:40 pm
Been upvoted: 1 time

Re: Identifying monodentate ligands

Postby shevanti_kumar_1E » Sun Dec 06, 2020 1:59 pm

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
Posts: 77
Joined: Wed Sep 30, 2020 9:35 pm

Re: Identifying monodentate ligands

Postby Sedge Greenlee » Sun Dec 06, 2020 4:03 pm

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
Posts: 85
Joined: Fri Mar 06, 2020 12:15 am

Re: Identifying monodentate ligands

Postby AlyssaMaynard1C » Sun Dec 06, 2020 4:06 pm

shevanti_kumar_2I wrote: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
Posts: 85
Joined: Wed Sep 30, 2020 9:59 pm

Re: Identifying monodentate ligands

Postby AndrewNguyen_2H » Sun Dec 06, 2020 4:10 pm

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
Posts: 59
Joined: Wed Sep 30, 2020 10:00 pm
Been upvoted: 1 time

Re: Identifying monodentate ligands

Postby Connie Liang 3L » Thu Dec 10, 2020 9:26 pm

Understood, thanks for the replies everyone!


Return to “Shape, Structure, Coordination Number, Ligands”

Who is online

Users browsing this forum: No registered users and 1 guest