tekkado
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Metal Complex Reaction Equations
Hi guys,
Im struggling a little bit with my reaction equations.
For our lab practical we prepared different metal complexes and now have to provide the reaction equations for them in our report.
As an example we prepared [NiCl2(PPh3)2]
This was done by refluxing triphenylphosphine in isopropanol, to which was added a solution of NiCl2.6H2O in ethanol that was prepared prior. This was
refluxed and the precipitate collected.
I understand writing them out as their species and balancing them but how do i write out the first part that consisted of two seperate solutions?
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Boffis
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I am not sure I quite understand your problem. The making of the two separate solutions do not involve reactions. The alcohols are just the medium and
can be ignored in the equation. It is just possible that some of the nickel chlorides coordinated water may be lost to the ethanol and in part
replaced by the latter but this sort of interaction with the solvent is generally ignored unless it has bearing on the outcome of the reaction.
Your example is unusual in that there is no real reaction, no ions or electrons exchanged, no hard bonds broken. You are merely exchanging
co-ordinated water molecules for triphenylphosphine molecules. It forms a coordination complex with the nickel by sharing its free electron pair with
the nickel. The water simply goes into the solution.
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Hegi
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Quote: Originally posted by tekkado  | Hi guys,
Im struggling a little bit with my reaction equations.
For our lab practical we prepared different metal complexes and now have to provide the reaction equations for them in our report.
As an example we prepared [NiCl2(PPh3)2]
This was done by refluxing triphenylphosphine in isopropanol, to which was added a solution of NiCl2.6H2O in ethanol that was prepared prior. This was
refluxed and the precipitate collected.
I understand writing them out as their species and balancing them but how do i write out the first part that consisted of two separate solutions?
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This question sounds very strange for the person who is already in the lab preparing coordination compounds. You should be already familiar with
theoretical aspects of coordination chemistry. The first step is just dissolution of your ligand in a hot solvent - no need to write anything. The
second step is the reaction where coordination bonds are formed and the old ones are broken down. So yes simply said it is substitution. You get a
low-spin diamagnetic square planar complex according to literature.
Our webpage has been shut down forever cause nobody was willing to contribute. Shame on you all!!!
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