Subject: Any (Pyrrolyl)Mn(CO)3 calculations.

From: "Michael Nolan (WannaBe Quantum Chemist)" <[email-masked]>
Date: Tue, 10 Jun 1997 12:29:01 +0100 (BST)

Hi CCL.

I've got a question I would like to ask.

Firstly some background.

I finished my BSc. project work this week; bound and handed up my report
this morning. It involved calculations on CpMn(CO)3, BzCr(CO)3 and, most 
importantly of all (Pyrrolyl)Mn(CO)3. The reason (Pyrrolyl)Mn(CO)3 is
important is because my supervisor is running photochemical experiments on
this complex. He believes that it will undergo ring slip, at short to
medium wavelengths and at long wavelengths CO loss.

 So the idea of the calculations was to work out the MOs of this complex
in order to perhaps predict the photochemical behaviour. WE also wanted to
run calculations on CpMn(CO)3 and BzCr(CO)3; the photchemical behaviour of
these is well known - exclusively CO loss. The question is, is this due to
reducing the symmetry of the arene ring, from D5h to C2v?. Our strategy
was to examine the composition of the virtual MOs - are they CO
anti-bonding or Arene anti-bonding.We had no success in the calculations 
on the three complexes (I have a previous post detailing this). So we
carried out a fragment analysis and allowed them to interact. We obtained
MO diagrams that are similar to previous work, e.g. that of Hoffmann and
co-workers from the late 1970s and early 1980s, M. B. Hall etc. We also
obtained an MO diagram for (Pyrrolyl)Mn(CO)3. To my knowledge, this was
the first calculation on this complex. I have predicted that it has a
pyrrolyl anti-bonding orbital that lies at short to medium wavelength from
the HOMO. Naturally I do not have any numbers

What I would like to know is do there exist any recent calculations on any
of these complexes, or has anyone done any work that was unpublished;
in particular using MP, CI, CC, DFT etc - as I was only able to use RHF.
This is in order that I may compare my (admittadly not-so-hot) results to
previous work.

Sorry for bothering you and thanking anyone in advance who replies.

Der Kobold hat gesprochen

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Michael Nolan (nearly BSc.;15 days to go)Dublin City University
41 Woodview				Chemistry (Quantum)
Lucan
Co. Dublin

IRELAND

Tel: + 353 1 6283035 (home)
Email: [email-masked]

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