Anthony KERMAGORET - THESES ET MEMOIRES DE L'UDS

Abstract
Chapitre V
The N,P,N type ligands bis(2-oxazoline-2-ylmethyl)phenylphosphine 1, bis(2-
oxazolin-2,5,5-trimethyl)phenylphosphine 2, phenyl-bis(2-picolyl)phosphine 3 and
bis((pyridin-2-yl)methyl) phenylphosphonite 4 were synthesized and characterized by 1 H, 13 C
{ 1 H} and 31 P{ 1 H} NMR. They were used to synthesize the corresponding Ni(II) complexes
[Ni{bis(2-oxazoline-2-ylmethyl)phenylphosphine}Cl2] 6, [Ni{bis(2-oxazolin-2,5,5-
trimethyl)phenylphosphine}Cl2] 7, [Ni{phenyl-bis(2-picolyl)phosphine}Cl2] 8 and
[Ni{bis((pyridin-2-yl)methyl) phenylphosphonite}Cl2] 9, respectively. The iron complexes
[Fe{phenyl-bis(2-picolyl)phosphine}2{FeCl3OFeCl3}] 10, [Fe{bis(2-oxazoline-2-
ylmethyl)phenylphosphine}2{FeCl3OFeCl3}] 11 and [Fe{bis(2-oxazolin-2,5,5-
trimethyl)phenylphosphine}Cl2] 12, synthesized by reaction of FeCl2·4H2O with ligands 1-3,
respectively, have been characterized by X-ray diffraction. The crystal structures of the
octahedral complexes 10 and 11 show that two tridentate ligands are facially coordinated to
the metal centre and the dianion (µ-oxo)bis[trichloroferrate(III)] compensates the doubly
positive charge. In contrast to 10 and 11, the crystal structure of 12 revealed a tetrahedral
geometry with the N,N coordination of one ligand and the P-Fe distance of 4.336(1) Å
establishes that of the phosphorus atom is not coordinated to the metal centre. The complexes
[Pd(Me){Bis(2-oxazolin-2,5,5-trimethyl)phenylphosphine}Cl] 13, [Pd{Bis(2-oxazolin-2,5,5-
trimethyl)phenylphosphine}Cl2] 14 and [Pd(NCCH3){bis(2-oxazolin-2,5,5-
trimethyl)phenylphosphine}(BF4)2] 15 were prepared by reaction of ligand 2 with
[Pd(Me)Cl(COD)] (COD = cyclooctadiene), [PdCl2(NCPh)2] or [Pd(MeCN)4(BF4)2],
respectively. In contrast to complex 11, the IR and NMR studies of complexes 13 and 14
established the coordination of the phosphorus atom and of one of the two oxazoline moieties
to the metal centre and the tridentate coordination of 3 in complex 15. The cobalt complexes
[Co{bis[1-(4,4-dimethyl-4,5-dihydrooxazol-2-yl)-1-ethylethyl]phenylphosphonite}Cl2] 16,
[Co{Bis(2-oxazoline-2-ylmethyl)phenylphosphine}Cl2] 17, [Co{Bis(2-oxazolin-2,5,5-
trimethyl)phenylphosphine}Cl2] 18 and [Co{phenyl-bis(2-picolyl)phosphine}Cl2] 19 were
prepared by reaction of anhydrous CoCl2 with the ligands NOPON Me2
(bis(oxazolinyl)phenylphosphonite), 1, 2 or 3, respectively. The crystal structure of 16 has
been determined by X-ray diffraction and showed a distorted tetrahedral coordination
geometry involving the phosphorus atom and one of the two oxazoline functions. In contrast
2