Jaroschik, Florian (2007) Synthesis of organophosphores complexes of di -and trivalent lanthanides and their application in catalysis. PhD thesis DCPH, DCPH, EP/X p.221.

Alternative Locations: http://www.imprimerie.polytechnique.fr/Theses/Files/Jaroschik.pdf

Abstract

Organo!
lanthani
de chemistry has long been dominated by cyclopentadienyl-based ligands whereas phosphorus-containing ligands have attracted interest only recently. In this work we show the influence of organophosphorus ligands on the synthesis and reactivity of organolanthanide compounds in three different areas. The first part is dedicated to the synthesis of “new” divalent organolanthanide complexes using both cyclopentadienyl and phospholyl based ligands. A new synthetic method - the reductive approach - is developed which allows the synthesis of base-free divalent thulocenes and unprecedented divalent dysprosium and neodymium ate-complexes. Small molecule activation with these new divalent compounds reveals their strong reducing nature and some differences between cyclopentadienyl- and phospholyl-containing complexes. The second part describes the synthesis of the first trivalent monophospholyl-bis(o-dimethylaminobenzyl)lanthanide complexes by classical salt-metathesis!
reactions. In addition, a stable 1H phosphole is used for the first time in a σ-bond metathesis reaction. The application of these compounds in styrene polymerization is reported. The third part deals with the synthesis and reactivity of new lanthanide mono-and biscarbene complexes using the dianionic 1,1-dilithio-bis(diphenylthiophosphinoyl) methane as carbene precursor. A discussion on the nature of the Ln-C multiple bonds via structural and reactivity analysis is included.

Table of content

Table of Contents
Introduction 1
Part I: Synthesis and reactivity of “new” divalent organolanthanide
complexes: Exploring the reductive approach 23
1 Introduction 25
2 Development of the reductive approach using samarium chemistry 29
2.1 Attempted preparation of a tris(phospholyl)samarium(III) precursor 29
2.2 Preparation of organosamarium(III) precursors carrying bulky cyclopentadienyl and phospholyl
ligands 31
2.3 Reduction of new organosamarium(III) precursors 34
2.4 Conclusion 35
3 Accessing divalent organothulium compounds by metathesis and reductive approach 36
3.1 Synthesis of [(Cpttt)2Tm] and [(Cp’’’)2Tm(THF)] by the metathesis reaction 36
3.2 Preparation of organothulium(III) precursors with bulky Cp ligands 39
3.3 NMR studies of organothulium(III) complexes with bulky Cp ligands 41
3.4 Reduction of organothulium(III) precursors 44
3.5 Use of other counterions 45
3.5.1 Precursor synthesis 45
3.5.2 Reduction of the borohydride precursor 46
3.6 Use of less bulky ligands 46
3.6.1 Synthesis of trivalent precursors with less bulky Cp ligands 47
3.6.2 Attempted reduction of the trivalent precursor carrying the Cptt ligand 50
3.7 Use of phospholyl ligands in the reductive approach 51
3.7.1 Preparation of trivalent precursors with phospholyl ligands 51
3.7.2 Reduction of trivalent precursors with phospholyl ligands 52
3.8 Synthesis of mixed ligand complexes 54
3.8.1 Preparation of trivalent mixed-ligand precursors 54
3.8.2 Reduction of mixed ligand precursors 56
3.9 Reactivity studies on divalent organothulium complexes 57
3.9.1 Dinitrogen activation 57
3.9.2 Oxidation with I2 and AgI 57
3.9.3 Oxidation with [(Dtp)2Pb] 59
3.9.4 Reaction with Ph3PS and Ph3PO 60
3.9.5 Reaction with pyridine 61
3.9.6 Reaction with nitrile 63
3.9.7 Further observations 64
3.10 Conclusion 64
4 Expanding the reductive approach to divalent organodysprosium chemistry 66
4.1 Preparation of organodysprosium(III) precursors with bulky ligands 66
4.2 Characterization of trivalent organodysprosium complexes by 1H NMR 69
4.3 Reduction of organodysprosium(III) precursors carrying the Cpttt ligand 70
4.4 Attempted reduction of other precursors 77
4.5 Reactivity tests 78
4.5.1 Dinitrogen activation 78
4.5.2 Reaction with diphenylacetylene 78
4.5.3 Reaction with Ph3PS and Ph3PO 79
4.5.4 Reaction with fluorenone 79
4.5.5 Reaction with biphospholes and thalliumphospholide 80
4.6 Conclusion 81
5 Further development of the reductive approach towards divalent organoneodymium
compounds 82
5.1 Preparation of organoneodymium(III) precursors bearing the Cpttt ligand 82
5.2 Reduction of organoneodymium(III) precursors 85
5.3 Reactivity studies 87
5.3.1 Aromatic solvents 87
5.3.2 Dinitrogen activation 87
5.3.3 Reaction with fluorenone 87
5.4 Conclusion 87
6 Conclusion and Outlook 88
References 92
Part II: Synthesis and characterization of mono(phospholyl)lanthanide
complexes and their use in polymerization catalysis 95
1 Introduction 97
2 Synthesis of monophospholyl lanthanide complexes 101
2.1 Synthesis of Sm and Y complexes 101
2.2 Synthesis of Sc complexes 102
2.2.1 Salt metathesis approach 102
2.2.2 σ-bond metathesis approach 103
3 X-ray structure analyses 104
3.1 Monophospholyl dihalide complexes 104
3.2 Monophospholylbis(benzyl)complexes 105
3.3 THF-ring opening with Sc 107
4 Polymerization tests with monophospholylbis(benzyl) complexes 109
5 Conclusion and Outlook 110
References 113
Part III: Synthesis and characterization of new lanthanide mono and
bis-carbene complexes: investigations on the nature of the
Ln-C multiple bond 115
1 Introduction 117
2 Synthesis of mono(carbene) complexes of samarium and thulium 119
3 Synthesis of homoleptic bis(carbene) complexes of samarium and thulium 121
4 Reactivity tests 124
4.1 Reactivity towards electrophiles 124
4.2 Nucleophilic substitution 127
5 Conclusions on the nature of the Ln-C multiple bond 129
6 Conclusion and Outlook 131
References 133
Conclusion and Perspectives 135
Experimental Part 141
Supplementary material 169

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