Subject: re:J.J. Isbell/Austin

From: Patrick Bultinck <[email-masked]>
Date: Tue, 26 Oct 1993 12:12:00 +0100 (MET)

Dear John,

I have read your letter dd. Oct. 25Th. I have to tell you that
we have not yet made a lot of calculations. However I am going
to tell you something about the objectives of my research for
the next four years. I am going to make ab initio calculations
on some complexes formed between the ions of the earth alkaline
metals Mg, Ca and Ba. As ligands I will consider some C2 
and C3 bidentates (Ethylenediamine and O and S analogs, 
1,3-Propanediamine and analogs) The reason to start here is to
try and understand the quantumchemical background of the
macrocyclic effect. Later on I will study the ligands, and
complexes formed with 12-ane-N4 and 14-ane-N4 (cyclam) and the
O and S analogs. The reason for the choice of the metals is
that we have to take ions with no unpaired electrons before 
complexation (this reduces the computer time needed to perform
calculations involving the ions (I wish to study basissets 
that would stress ionic character of these metals)). I am 
fully aware of the fact that some of these complexes will not 
be very stable, but this is an ab initio exploration to find 
out if we CAN EVEN handle these compounds without going at war 
with computertime etc.. Of course it will be necessary to use 
RECPs for the metals (relativistic electron core potentials, 
based on the Dirac equation) The open-chain ligands will be 
searched for their minimal energy conformations, and the 
energy calculated for every value of the CNNC dihedral angle 
(two dihedral angles for the C3 ligands) For the complexes 
formed we will examine the optimal geometry as well, and will 
examine if the geometry has been altered a lot or not. An 
optimization will be performed for the macrocycles too. (con-
sidering only a number of possible structures due to the very 
big number of dihedral angles) The geometry of the formed 
complexes will be stušdied... Different properties of the bond 
in the complexes will be studied through analysis of the wave 
function (overlap between different atomic orbitals (or better 
basisfunctions)). Also we will try to study the effect of 
relativity on our calculations. As quantum chemical method to 
be used we will perform Hartree-Fock calculations with Moller-
Plesset perturbation for electron correlation. I will do 
no experimental work (but there is a group on this lab that 
does only do experimental work, they have already published in 
Bull. Soc. Chem. Belges and in the Journal of Coordination 
Chemistry (look for the names Goeminne A.M. and Herman G.))
If YOU have information on the structure of different
complexes or on gas-phase stability constants for the complexes
formed, I would enjoy it if you could help me out.
You have referred to your calculations, might I
know what calculations you are doing ? 
I hope to have helped you with this information, 
If any questions do not hesitate to contact me,  

Greetings,
Patrick Bultinck  
Universty of Ghent  
Laboratory for General and Inorganic chemistry  
Krijgslaan 281 (S3)  
B-9000 Gent  
Belgium 

E-mail : [email-masked]