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Jean-Pierre Daudey

Publications and source records attributed to Jean-Pierre Daudey.

2 recordsLinked to original sources

Using effective group potential methodology for predicting organometallic complex properties.

Using the Effective Group Potentials (EGP) method, optimal geometries, harmonic vibrational frequencies, and relative energies of different sets of metal complexes are calculated. All of the systems under consideration contain the cyclopentadienyl (Cp) ligand. They are as follows: (i). Group V metal Atom complexes showing one Cp ligand, (ii). a tetrameric Al-Cp compound with four Cp ligands, (iii). homometallic lutetium hydrides containing six cyclopentadienyl rings. Various electron correlation treatments have been carried out. All of the results compare very satisfactorily with available experimental data and with all-electron ab initio calculations performed for this work or published in the literature. Furthermore, the performance of the EGP method was tested on a rather large complex for which experimental evidence exists, but no all-electron calculation has been reported so far.

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Ab Initio Calculations of the Magnetic Coupling between a Ni(II) Ion and Two Nitroxide Radicals in cis and trans Positions.

The magnetic couplings between a Ni(II) center in an octahedral environment and two nitroxides in its coordination sphere are calculated by ab initio methods. The system is well described by a Heisenberg model. Fully variational calculations (DDCI2) give results similar to those of combined variational/perturbative calculations (CASPT2), and some DFT results are obtained. The effect of some structural parameters is studied: the cis and trans positions and the angles and the distances of the nitroxides with respect to the nickel center. We show that the magnetic couplings are almost the same in the cis and in the trans complexes; thus, the only relevant geometric parameters for ferromagnetic or antiferromagnetic couplings are the orientations and the distances of the nitroxide ligands with respect to the Ni(II) center. Direct exchange between the magnetic centers is calculated: it depends neither on the angles nor on the cis or trans conformations, showing that the superexchange contribution is the only angle-dependent one.

Journal Article↗