Anthony KERMAGORET - THESES ET MEMOIRES DE L'UDS

Chapitre V
cyclic voltammograms of 10 and 11 showed two reversible redox couples attributed to the
reduction of the dianion (Fe2OCl6) 2- (-0.237 mV for 10 and -0.198 mV for 11 vs. SCE) and to
the oxidation of the Fe(II) ion of the complex (0.668 mV for 10 and 0.521 mV for 11 vs.
SCE). The cyclic voltammogram of 12 showed a reversible redox couple at -0.168 mV vs.
SCE assigned to the oxidation of Fe(II) atom and an irreversible process at 0.65 mV. The
complexes 10-12 did not show significant activities in ethylene oligomerization with AlEtCl2
or MAO as cocatalyst.
Complexes 13 and 14 were synthesized by reaction of 3 with [Pd(Me)Cl(COD)] or
[PdCl2(NCPh)2], respectively. The presence of coordinated oxazoline function and
uncoordinated oxazoline functions was confirmed by 13 C{ 1 H} and 1 H NMR spectroscopy and
IR spectroscopy. Complex 15, synthesized by reaction of 3 with [Pd(MeNC)4(BF4)2] , showed
the tridentate coordination of 3 to the metal center.
The cobalt complexes 16-19 have been synthesized by reaction of anhydrous CoCl2 with the
ligands (NOPON Me2 ), 1, 2 and 3, respectively. The crystal structure of 16 showed a distorted
tetrahedral geometry with the coordination of the phosphorus and one of the two oxazoline
functions of the ligand. The presence of a coordinated and uncoordinated oxazoline ligand
was still confirmed by the presence of two C=N vibration bands in its IR spectrum. In contrast
to 16, the IR spectrum of the green complex 17 showed only the presence of coordinated
pyridine functions. Precatalyst 16 has been evaluated in oligomerization of ethylene with
MAO or AlEtCl2 as cocatalyst but it did not present significant activity with 400 equiv of
MAO. However, at 80 °C and under a pressure of 30 bar, 16 showed an activity of 17700 mol
C2H4/(mol Co·h) with 6 equiv of AlEtCl2.
5. Experimental section
General consideration: All reactions were performed under purified nitrogen. Solvents were
purified and dried under nitrogen by conventional methods. The 1 H NMR spectra were
recorded at 300 MHz, 31 P{ 1 H} NMR spectra were recorded at 121.5 MHz, and 13 C{ 1 H} NMR
spectra were recorded at 75.5 MHz on a FT Bruker AC300 instrument. IR spectra in the range
of 4000-400 cm -1 were recorded on a Bruker IFS28FT. Gas chromatographic analyses were
performed on a Thermoquest GC8000 Top Series gas chromatograph using a HP Pona
column (50 m, 0.2 mm diameter, 0.5 µm film thickness). Magnetic moments were determined
by the Evans method in CD2Cl2 using a solution of CH3NO2 in CD2Cl2 (20:80, v/v) as
reference. Mass spectra were recorded with a Bruker Daltonics microTOF (ESI; positive
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