Metal complexes

[x10694]

---

Members don't see this ad.

Hi all,
I am a little confused about metal complexes. In a metal complexs, does a ligand actually make a bond with the metal? as in coordinate bond? If it does why do many complexes have a charge identical to the charge of the metal? for instance [Cu(NH3)6]2+ ? Thanks!

 

[Foghorn]

NH3 is a strong field ligand based on the spectrochemical series of ligands. Even though it forms 6 molecular orbital sigma bonds with d9 Cu^2+, each electron pair is energetically closer to NH3. As a consequence the e- pair is localized on NH3 and the formal charge of the complex localized on Cu.

An easier way of calculating the overall charge for a [M(Lx)]^n+ (x = # of ligands) TM complex is to look at the charge of the ligand and metal before TM complex formation. If the ligand has a neutral charge, as in this case, then the complex will have the same overall charge as the metal. If the complex has 6 F- weak field ligands, then the octahedral TM complex [CuF6]^4- forms. Basically, there's conservation of charge.

 

[x10694]

Thanks!!👍