Sciencemadness Discussion Board

Chlorate as a Ligand

12AX7 - 13-5-2007 at 11:56

- Any thoughts? It has a lone pair.

JohnWW - 13-5-2007 at 15:17

Unlikely, - for (a) steric reasons, (b) the electron-drawing power of the three O atoms, and (c) its lone pair being quite tightly bonded. BH3, which would overcome the steric factor as a ligand, is liable to be explosively oxidized by Cl03-. Another strong Lewis acid is BF3, which would overcome this liability, but it would introduce steric strain.

12AX7 - 13-5-2007 at 16:35

Ah yes, that sounds plausible.

Lewis acids aren't something I've covered in school, FWIW.

How about a strong non-oxidizable Lewis acid like FeCl3 or AlCl3? I don't know how strength compares to BH3/BF3... Meh, Al would probably rather have the oxygen atoms!

Tim

guy - 13-5-2007 at 17:14

Of course it can be a ligand. But whether or not if forms a ligand is relative. For example, should [Fe(H2O)6]3+ lose its water to bond with chlorate? Probably not. But thats only because the H2O is better ligand. But theoretically anything with lone pairs can be a ligand.

For example, nitrates, you would never think of as a ligand but in some certain, very hard lewis acids like Ce4+, it will form a nitrato complex.
http://en.wikipedia.org/wiki/Ammonium_cerium(IV)_nitrate

DerAlte - 14-5-2007 at 20:38

12AX7 - now that rings a bell to an oldie like me! It was a double triode, I believe. Sorry to be off topic...

DerAlte

Dr. Beaker - 15-5-2007 at 10:52

in clorate you can say each oxygen bares 1/3 of the negative charge. the lone pair of clorine, and those of oxygens are expected to be firmly held by their atoms, i.e, clorate is a crapy sigma donor. however, the Cl-O anti bonding pi orbital may accept e- density from an electron reach metal, i.e a good pi acceptor. Cl may also utilize its 3d orbitals for that purpose.
the chlorate however is likely to participate in redox reactions with these electron reach metals...

[Edited on 15-5-2007 by Dr. Beaker]