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Simulation of Plasticity of Copper(II) Coordination Polyhedron: Empirical Force Field Model with Distorsion Coordinate Potential

Jasmina Sabolović ; Institute for Medical Research and Occupational Health; University of Zagreb, 41001 Zagreb, Croatia, Yugoslavia
Nenad Raos ; Institute for Medical Research and Occupational Health; University of Zagreb, 41001 Zagreb, Croatia, Yugoslavia
Kjeld Rasmussen ; Chemistry Department, Technical University of Denmark, DK-2BOO Lyngby, Denmark

Sažetak

In order to reproduce the geometry of tetracoordinated copper
(II) chelates with a »distorted« coordination polyhedron (planar/
/tetrahedral), two new empirical functions for the calculation of
the conformational potential were introduced. The first depends
on the distorsion coordinate (1, defined as an angle between bisectors
of two valence angles around the central atom. The second
function is a two-well valence angle bend ing potential for valence
angles around copper, with minima at 90" and 109.47°.
The new functions were tested on bis-(N,N-dimethylvalinato)-
copper(II). A consistent force field (CFF) calculation with the new
functions yielded the correct geometry of copper coordination, i. e.
a distorted tetrahedron. The valence angles around copper (N-
-Cu-N, O-Cu-N and O-Cu-O) were reproduced fairly well
with root-mean square deviation with respect to the crystal structure
of 3.20° and 3.73° for the model with a two-well and the
model with a quadratic valence angle bending potential, respectively.
The measured diastereoselectivity (Gibbs energy difference
between CU(L-ligand12 and Cu=ligand) (o-ligand)) was reproduced
within 3 kJ mol-1.

Ključne riječi

Hrčak ID:

175809

URI

https://hrcak.srce.hr/175809

Datum izdavanja:

10.10.1989.

Posjeta: 872 *