Jump to content

your opinion about the geometry


Recommended Posts

Hey everyone,


I was just wondering in the VO(acac)2 which is a Vandium (IV) complex the V=O bond length is significantly shorter than V-O bond length so the discription that it has a square-pyramidal geometry is somewhat misleading. what do you guys thing?


I know that in books and at various places it is stated to be square-pyramidal. I am also suspecting some distortion because of the Jahn-teller effect?


your opinion on that is welcome.


PS. I just realised I said Jahn-teller distortion which is obviuosly not possible for this complex.

Edited by ChemSiddiqui
Link to comment
Share on other sites

acac is shorthand for a 2,4-Pentanedione ligand--common name ACetylACetone. This ligand is bidentate and has two donor atoms--the two oxygens. This suggests two points of attachment and you have placed two acac groups on the V central atom--accounting for all four of the equatorial bonds. I'm fairly certain both acac ligands take on an aromatic character when bonding to the metal as well--I have the proton NMR's for a Co(acac)3 which has a singlet integrating to 1, shifted down to just shy of 6. The lone oxygen will occupy an axial position and it leaves room for a sixth ligand to come in from the bottom... square pyramidal is actually quite a common geometry for this type of molecule.


Wikipedia has a pretty decent picture of it where you can more clearly see the square-pyramidal structure:


Edited by aeontide
Link to comment
Share on other sites

Thanks aeontde for that but that is what I already know. I merely wanted opinion on the geometry, because in this complex vanadium can adopt the 5 or 6 coordination. but anyway, you are right acac- do have the aromatic character. I got the bond length data and similar bond lengths suggest delocalisiation.


thanks again.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.