[chrisso80b]

Hi, Im having a lot of trouble understanding how to assign ground state terms? I dont really know where to begin.
I am meant to be assigning the ground state terms for Co(acac)₃ and Co(acac-NO₂)₃ (assuming weak field ligand)
How do I go about doing this? Any help/ links/ pdf's showing this would be really useful!
Thanks!

[dipesh747]

Hi.

Firstly you need to know the structure of the compounds, here is a link for the first one. http://www.google.co.uk/imgres?imgurl=http://img.skitch.com/20100919-ckikqtfpsf9sf5f2sn6qah8t6i.jpg&imgrefurl=http://www.chemicalforums.com/index.php%3Ftopic%3D43629.0&h=441&w=1364&sz=58&tbnid=mmUHNj_RoK4DLM:&tbnh=44&tbnw=135&prev=/search%3Fq%3DCo(acac)3%26tbm%3Disch%26tbo%3Du&zoom=1&q=Co(acac)3&docid=CTs8FbOXq9gsYM&sa=X&ei=i9glT4CzJMix0QXQzLDOCg&ved=0CFUQ9QEwBQ&dur=3286

You then need to assign the d electron count.
After you have done this, by looking at the structure you need to determine the shape of the complex (octahedral, tetrahedral etc). The using crystal field theory, determine the splitting of the degenerate d orbitals upon complexation. For octahedral you will get T2g and Eg.

Then fill up these orbitals according to the number of d electrons.

Depending on the populations of these orbitals there may be some jahn teller distortion (generally if there are unsymmetrical populated energy levels this distortion will occur.)

Check out Inorganic chemistry by Housecroft if you are still having trouble with this topic.