Thèse présentée pour obtenir le grade de

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Thèse présentée pour obtenir le grade de Docteur de l'Université Louis Pasteur Strasbourg I par Pierre KUHN Discipline : Chimie Modulation des Propriétés Electroniques et Stériques de Nouvelles Phosphines Chélatantes. Applications en Oligomérisation et Polymérisation de l'Ethylène. Soutenue publiquement le 01. 06. 2006 Membres du jury Directeur de Thèse : Dominique Matt, Directeur de Recherche au CNRS, ULP, Strasbourg Directeur de Thèse : Pierre Lutz, Directeur de Recherche au CNRS, ICS, Strasbourg Rapporteur Interne : Patrick Pale, Professeur, ULP, Strasbourg Rapporteur Externe : Jean-François Carpentier, Professeur, Université de Rennes I Rapporteur Externe : Klaus Müllen, Professeur, Max Planck Institüt, Mainz Laboratoire de Chimie Inorganique Moléculaire, LC 3 CNRS-ULP Institut Charles Sadron, UPR 22 CNRS

  • electronic effects

  • modulation des propriétés electroniques

  • stériques de nouvelles phosphines

  • strasbourg rapporteur

  • membres du jury directeur de thèse

  • structure-reactivity relationships

  • directeur de la recherche


Publié le : mercredi 20 juin 2012
Lecture(s) : 238
Source : scd-theses.u-strasbg.fr
Nombre de pages : 182
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Thèse présentée pour obtenir le grade de
Docteur de l’Université Louis Pasteur Strasbourg I

par
Pierre KUHN


Discipline : Chimie



Modulation des Propriétés Electroniques et Stériques de
Nouvelles Phosphines Chélatantes.
Applications en Oligomérisation et Polymérisation de
l’Ethylène.




Soutenue publiquement le 01. 06. 2006



Membres du jury

Directeur de Thèse : Dominique Matt, Directeur de Recherche au CNRS, ULP, Strasbourg
Pierre Lutz, Directeur de Recherche au CNRS, ICS, Strasbourg

Rapporteur Interne : Patrick Pale, Professeur, ULP, Strasbourg

Rapporteur Externe : Jean-François Carpentier, Professeur, Université de Rennes I
Klaus Müllen, Professeur, Max Planck Institüt, Mainz





Laboratoire de Chimie Inorganique Moléculaire, LC 3 CNRS-ULP
Institut Charles Sadron, UPR 22 CNRS























La pensée ne doit jamais se soumettre, ni à un dogme, ni à un parti, ni à une
passion, ni à un intérêt, ni à une idée préconçue, ni à quoi que ce soit, si ce
n’est aux faits eux-mêmes, parce que, pour elle se soumettre, ce serait cesser
d’exister.

Henri Poincaré






























Un grand Merci à tous celles et ceux qui ont rendu possible ce travail, ou qui
ont, directement ou indirectement, continuellement ou sporadiquement,
contribué à sa réalisation.

Je tiens également à remercier les Professeurs Jean-François Carpentier, Klaus
Müllen et Patrick Pale pour m’avoir fait l’honneur d’évaluer ce travail.



Contents


General Introduction and objectives..................................................................................... 9
General Introduction ................................................................................................................. 9
Objectives................................................................................................................................ 12
References.......... 14


CHAPTER 1:
Structure-Reactivity Relationships for [Ni(P,O)R(L)] Complexes, a Class of Versatile
Catalysts for the Oligomerisation and Polymerisation of Ethylene ................................. 17
I. Introduction.................................................................................................................... 18
II. General properties of [Ni(P,O)R(L)] complexes ........................................................... 19
A. Description of the catalytic cycle ............................................................................. 19
B. Synthesis of the active species ................................................................................. 20
C. Deactivation pathways.............................................................................................22
III. Influence of the L ligand ................................................................................................ 23
A. Influences of the nature of L. ................................................................................... 23
B. Influence of the L:Ni ratio........................................................................................ 26
IV. Variation of the P,O chelate part.................................................................................... 27
A. Variation of the P -substituents.......................................................................... 27 chelate
1. In the absence of L ligand. 27
2. In the presence of L............................................................................................... 28
B. Variation of the P,O backbone ................................................................................. 30
1. Electronic effects of substituents positioned on the C and C atoms ............. 31 α-P β-P
2. Steric effects of substituents positioned on the C and C atoms .................... 35 α-P β-P
3. Bimetallic catalysts36
4. Changing the length of the chelate backbone........................................................ 38
5. Neutral vs. anionic P,O chelators .......................................................................... 40 V. Conclusion...................................................................................................................... 42
References ............................................................................................................................... 44


CHAPTER 2:
An Efficient Keim-Type Catalyst Based on an Electron-Poor P,O-Chelate; Tuning the
Selectivity of Ethylene Oligomerisation towards Short α-Olefins.................................... 48
Introduction ............................................................................................................................. 49
Results and discussion............................................................................................................. 50
Synthesis............................................................................................................................ 50
Catalytic study................................................................................................................... 52
Experimental section............................................................................................................... 54
References ............................................................................................................................... 62


CHAPTER 3:
Can Weak Interactions Modify the Binding Properties of a Strong Nitrogen Donor?
Unusual N-Coordination of a Phosphoranylidene-Substituted Pyrazolone Unit Towards
Palladium(II) Centres: an Experimental and Theoretical Study ..................................... 63
Introduction ............................................................................................................................. 64
Results and discussion............................................................................................................. 65
Synthesis............................................................................................................................ 65
Theoretical study............................................................................................................... 69
Experimental section............................................................................................................... 75
References ............................................................................................................................... 79

CHAPTER 4:
Ethylene oligomerisation and polymerisation with nickel phosphanylenolates bearing
electron-withdrawing substituents. Structure-reactivity relationships............................ 82
Introduction ............................................................................................................................. 83
Results ..................................................................................................................................... 85
Synthesis of the complexes ............................................................................................... 85
Ethylene oligomerisation................................................................................................... 89
Ethylene polymerisation.................................................................................................... 91
Discussion ............................................................................................................................... 93
Conclusion.......... 97
Experimental section............................................................................................................... 98
References........ 105


CHAPTER 5:
Catalytic applications of keto-stabilised phosphorus ylides based on a macrocyclic
scaffold: calixarenes with one or two pendant Ni(P,O)-subunits as ethylene
oligomerisation and polymerisation catalysts................................................................... 108
Introduction ........................................................................................................................... 109
Results and discussion........................................................................................................... 111
Ligand synthesis.............................................................................................................. 111
Synthesis of catalytic precursors ..................................................................................... 116
Ethylene polymerisation.................................................................................................. 118
Ethylene oligomerisation................................................................................................. 120
Possible deactivation pathway of the bis-nickel complexes ........................................... 121
Conclusion............................................................................................................................. 123
Experimental section............................................................................................................. 124
References........ 141

CHAPTER 6:
Coordination Chemistry of Large Diphosphanes - Directional Properties of a
Calix[4]arene Proximally Substituted by Two -OCH PPh Podand Arms ................... 144 2 2
Introduction ........................................................................................................................... 145
Results and discussion........................................................................................................... 146
Synthesis.......................................................................................................................... 146
Ethylene oligomerisation................................................................................................. 151
Conclusion............................................................................................................................. 152
Experimental section............................................................................................................. 153
References........ 157


CHAPTER 7:
Phosphorus-phosphorus coupling in a diphosphine with a ten bond P•••P separation.160
Introduction ........................................................................................................................... 160
Results and discussion........................................................................................................... 161
Experimental section............................................................................................................. 166
References ............................................................................................................................. 170

General Conclusion............................................................................................................. 171
Conclusion générale ............................................................................................................ 174
Annex.....................................................................................................................................178 General Introduction and objectives


General Introduction

[1]Transition metals are at the core of a wide range of catalyst systems. In comparison to
main group metals, they possess more orbitals available for interactions, and with different
symmetry. Additionally, transition metals can combine specific functions, e.g. Lewis acidity,
substrate activation, red/ox chemistry and polar bonds. This diversity is a key factor in
imparting catalytic properties to transition metals and their complexes. The ability to bind
inert spectator ligands in addition to reactive moieties forms the basis for innovative transition
metal catalyst design. These ancillary ligands primarily control the configuration and
conformation of reactive coordinated substrates, and thus catalyst reactivity. Variation of the
properties, either electronic or steric or both, of such ligands offers the opportunity to tune
catalyst properties. The wide range of possible spectator ligands, metal oxidation states and
coordination numbers provides a near infinite array of potential catalysts.
The unique character of the metal-carbon bond is another important element of
(transition) metal-based catalysts that has been exploited in many catalytic (and
[2]stoichiometric) metal-mediated transformations. The wide range of available organometallic
metal-alkyl species offers a broad spectrum of reactivity with various substrates to allow
interesting opportunities for C-C, C-H, C-O, C-N and C-X bond formation. A very important
application of C-C bond formation with organometallic catalysts is the polymerisation and
copolymerisation of olefins and the closely related oligomerization of olefins.
The production of polyolefins is one of the most important area of chemical industry,
which estimated worldwide annual production of 80 million tons (in 2000) has witnessed a
[3]100% increase in production volume over the past decade only.
The first oligomerisation process was developed by Ziegler (Alfen process) in the early
50’s. During extensive studies on organoaluminium compounds, Ziegler discovered the
[4]Aufbaureaktion, a series of sequential repetitive olefin insertions into the Al-C bond (Fig. 1,
Eq. 1), which takes place under high ethylene pressure (100-400 bar) and moderate
temperatures (100-150°C). Relevant for the production of linear α-olefins was the observation
[5]that the insertion of ethylene into an Al-H bond is reversible (Fig1, Eq. 2), indicating that
olefin elimination can occur.

9 General Introduction and objectives
Eq. 1AlEt + 3n CH =CH3 2 2 Al n
3
R Eq. 2Al-H + RCH=CH Al2
Eq. 3AlEt + 3Al 3+ 3 CH =CHn 2 2 n-13
Figure 1.

Upon variation of the pressure, temperature and reaction time, it was possible to induce the
displacement of olefins (Verdrängung) affording triethylaluminum and three equivalents of α-
olefins (Fig. 1, Eq. 3), achieved at high temperature (250-400°C) and low ethylene pressure
[6](10 bar).
Several processes still involve alkyl-aluminum compounds for the production of α-olefins
[7,8] [9](Gulf/Chevron, Ethyl Corporation ).
The most important discovery made by Ziegler in 1952 was that in the presence of
nickel salts, the alkyl-aluminum catalysed Aufbaureaktion is directed to yield mainly butenes.
[4a,6] [10] This phenomenon is often referred to as the “nickel effect”. These findings initiated an
[11]intensive investigation into organo-nickel chemistry. Wilke was the first to observe ligand
[12]effects on selectivity in nickel-catalyzed reactions. Most of the nickel complexes that were
used were called “bare” or “naked” as the nickel atom is coordinated to ligands that could be
[12]quantitatively displaced by substrates or bind to only a few ligands.
During the late 60’s, upon extension of the ligand variations to bidentate [P,O]
chelators, Keim discovered highly active ethylene oligomerisation catalysts that produce
[13,14]linear α-olefins with excellent selectivity (Fig. 2).

P R
Ni
O L

Figure 2.

This type of catalysts forms the basis of the SHOP-process (Shell Higher Olefin Process),
which accounts for about 35% of the annual worldwide production of α-olefins made through
[15,16]ethylene oligomerisation. With an annual production of about 1 million tons, the SHOP
[15,16]is the largest single feed industrial application of homogeneous catalysis.
10

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