Organometallic and coordination chemistry of (Tetramethylcyclobutadiene)cobalt sandwich and halfsandwich complexes [Elektronische Ressource] / vorgelegt von Mikhail V. Butovskiy

Mikhail V. Boutovski

Informations

• Publié par: rheinisch-westfalischen_technischen_hochschule_-rwth-_aachen
• Publié le: 01 janvier 2005
• Nombre de lectures: 14
• Langue: English
• Poids de l'ouvrage: 1 Mo

Extrait

Organometallic and Coordination Chemistry of
(Tetramethylcyclobutadiene)cobalt Sandwich and Halfsandwich Complexes




Von der Fakultät für Mathematik, Informatik, und Naturwissenschaften
der Rheinisch-Westfälischen Technischen Hochschule Aachen
zur Erlangung des akademischen Grades eines
Doktors der Naturwissenschaften
genehmigte Dissertation



vorgelegt von


Diplom-Chemiker
Mikhail V. Butovskiy
aus Moskau



Berichter: Professor Dr. U. Kölle
Universitätsprofessor Dr. G. E. Herberich

Tag der mündlichen Prüfung: 2 August 2005



Diese Dissertation ist auf den
Internetseiten der Hochschulbibliothek
online verfügbar















































Meinen Eltern



























































Acknowledgements

I am most grateful to my dear teachers Prof. Dr. G. E. Herberich and Prof. Dr. U. Kölle for
suggesting the interesting topic of this dissertational work and providing the opportunity to work in
their laboratories, for interesting discussions and willingness to communicate knowledge and
experience. I sincerely appreciate their patience and understanding as well as the acceptance of my
not-always-easy way of working.

I also wish to thank:

Prof. Dr. U. Englert for performing many single crystal structure analyses;

T. Gossen for professional recording of 1D and 2D 500 MHz NMR spectra, which led to unequivocal
assignments of all synthesized compounds;

R. Boumahrat for recording routine 200 MHz NMR spectra and teaching me how to operate the NMR
spectrometer;

H. Ressel for outstanding repair and construction of glassware at the state of the art;

I. Dahmen-Regente and M. Lieffertz for their help with organizing many documents and solving
administrational problems;

All people from the electric and mechanical workshops for frequently repairing devices and
apparatus;

Finally all people of the institute for creating a pleasant and constructive working climate.

I am truly grateful to my parents T. Gordon and V. Butovskiy for their patience and understanding
when I was performing violent chemical reactions and explosions in my childhood at home. I
appreciate emotional support from my brother L. Butovskiy and his family and from all my relatives.

I address also my acknowledgements to Dr. A. R. Kudinov for his help with organizing my stay in
Aachen; Dr. D. Muratov, Dr. T. Basu Baul and K. Korczak for their company, good sense of humor,
and interesting conversations; Dr. B. Doumèche for the fun to visit different cities and towns of Germany and Belgium; D. Pankratov and family, Dr. O. Volkov and family for their help; university
friends (MSU 1999): Dr. A. Hvorost, G. Kipiani (crazy c hocolate fan), Dr. I. Taidakov, V.
Meshcheryakov, Dr. S. Minosyanz, A. Zimin, and Dr. A. Grippa for their friendship; A. Kritsina with
her violin for the moments of harmony; DivX Club: V. Karpinchyk, G. Tchvikhovskaia, and V.
Mikhalchenkova for their company and good sense of humor.

I am grateful to lecturers, teachers and all stuff involved in teaching at Moscow State University.
I appreciate all efforts which these people have made to share their knowledge and experience.

Finally, internet friends should not be forgotten: Tutankhamen, Andrew, Asmodey, Frikazoid, KPSS,
Steppenbaer, miv, Peter, Slivun, Vika, Tapochkin, alexela, mdim.























Parts of this work are already published:


M. V. Butovskii, U. Englert, A. A. Fil'chikov, G. E. Herberich, U. Kölle, A. R. Kudinov, Eur. J.
Inorg. Chem. 2002, 2656–2663.


M. V. Butovskii, U. Englert, G. E. Herberich, K. Kirchner, U. Kölle, Organometallics 2003, 22,
1989–1991.


M. V. Butovskii, U. Englert, G. E. Herberich, U. Kölle, Eur. J. Inorg. Chem. 2005, 971–980
























i
Contents

List of Abbreviations v
1. Formation and Ligand Substitution Reactions of (Tetramethylcyclobutadiene)cobalt 1
+ tris(ligand) ions [Cb*CoL ] 3

1.1 Introduction 1
1.1.1 Cyclobutadiene 1
1.1.2 Syntheses of (Cyclobutadiene)cobalt Complexes 3
n+ 1.1.3 Electrophilic Complex Fragments [L M(solv) ] 8 x y
1.1.4 The Aim of the Present Work 10
1.2 Starting Materials 11
* 12 1.3 Ligand Substitution Reactions of [Cb*Co(CO) ]BF [(1)BF ] and of Cb CoI(CO) (4) 3 4 4 2
1.3.1 Photolysis of (1)BF in Acetonitrile 12 4
1.3.2 Thermal and Photolytic Reactions of (1)BF with PMe and P(OMe) 14 4 3 3
1.3.3 Reactions of (1)BF and of 4 with Bipyridine 15 4
1.4 Photolyses and Thermal Reaction of [Cb*Co(C H )]PF [(3)PF ] 16 6 6 6 6
1.4.1 Photolysis in Acetonitrile and Formation of [Cb*Co(MeCN) ]PF [(2)PF ] 16 3 6 6
1.4.2 Photolysis in Liquid Ammonia and Formation of [Cb*Co(NH ) ]PF [(11)PF ] 17 3 3 6 6
1.4.3 Thermal Benzene Displacement in Acetonitrile and Formation of (2)PF 18 6
1.5 Ligand Substitution Reactions of [Cb*Co(MeCN) ]PF [(2)PF ] 19 3 6 6
1.5.1 Synthesis of [Cb*Co(C H N) ]PF [(13)PF ] 19 5 5 3 6 6
1.5.2 Synthesis of [Cb*Co{P(OMe) } ]PF [(9)PF ] 20 3 3 6 6
1.5.3 Reaction of (2)PF with PMe 20 6 3
1.5.4 Synthesis of [Cb*Co(CNtBu) ]PF [(16)PF ] 21 3 6 6
1.5.5 Synthesis of (NEt ) [Cb*Co(CN) ] (17) 22 4 2 3
1.6 NMR Spectroscopic Properties 22
Structures of [Cb*Co(CO) ]BF [(1)BF ] and [Cb*Co(MeCN) ]PF [(2)PF ] 1.7 23 3 4 4 3 6 6
1.8 Electrochemical Studies 25
1.9 Conclusion 26
42. Protonation of CpCoCb*: Ring-opening with Formation of a Novel s,h -Butadienyl 29
4 + Complex Cation [CpCo(s,h -C H Me )] 4 syn 4ii
2.1 Introduction 29
2.2 The Starting Complex CpCoCb* (18) 37
2.3 Protonation of CpCoCb* (18) 38
4 + + 2.3.1 Formation of [CpCo(s,h -C H Me )] (19 ) and Deuteration Experiment 38 4 syn 4
4 2.3.2 Structure of [CpCo(s,h -C H Me )]BF [(19)BF ] 42 4 syn 4 4 4
2.3.3 Stereochemistry of the Ring-opening Process 44
4 + + 47 Thermal Rearrangement of [CpCo(s,h -C H Me )] (19 ) with Formation of a 2.4 4 syn 4
5 + + Half-open Cobaltocenium Ion [CpCo(h -C H Me )] (21 ) 5 4 3
2.4.1 NMR Spectroscopic Observation of the Rearrangement and Deuteration Experiment 47
2.4.2 Kinetics of the Rearrangement 50
2.4.3 Mechanistic Conclusions 51
2.4.4 Preparation of (21)BF 51 4
2.4.5 Reactions of (21)BF with Hydride Donors 52 4
4 + + 54 2.5 Reactions of [CpCo(s,h -C H Me )] (19 ) with Nucleophiles 4 syn 4
5 2.5.1 54 Reaction with CNtBu and Formation of [CpCo{h -C Me (NHtBu)}]Tf [(24)CF SO ] 5 4 3 3
4 2.5.2 Deprotonation by Et N and Formation of CpCo[h -C H Me (CH )] (25) 56 3 4 syn 3 2
4 2.5.3 Structure of CpCo[h -C H Me (CH )] (25) 59 4 syn 3 2
2.5.4 Reaction with Pyridine and Unexpected syn/anti Isomerization 61
2.5.5 Discussion of the Isomerization in the Reaction with Pyridine 70
4 2.5.6 Structure of [CpCo{h -C H Me (NC H )}]Tf [(26)CF SO ] 75 4 anti 4 5 5 3 3
4 + + 2.5.7 Restricted Rotation of Pyridine in [CpCo{h -C H Me (NC H )}] (26 ) 78 4 anti 4 5 5
4 2.5.8 Reaction with PPh and Formation of [CpCo{h -C H Me (PPh )}]BF [(31)BF ] 79 3 4 anti 4 3 4 4
2.5.9 Deprotonation by DMSO and Formation of CpCoCb* (18) 82
4 + + 83 2.6 Nucleophilic Substitution of the Pyridine of [CpCo{h -C H Me (NC H )}] (26 ) 4 anti 4 5 5
2.6.1 A Pyridine/4-Picoline Exchange Reaction 83
5 2.6.2 Substitution with CNtBu and Formation of [CpCo{h -C Me (NHtBu)}]Tf 86 5 4
[(24)CF SO ] 3 3
– 4 88 2.6.3 Substitution with CN and Formation of CpCo(h -C H Me CN) (33) 4 anti 4
2.6.4 Reaction with Allylmagnesium Chloride 90
4 + +Abstraction of Pyridine from [CpCo{h -C H Me (NC H )}] (26 ) And Formation of 90 2.7 4 anti 4 5 5
4 4 + + a New s,h -Butadienyl Complex Cation [CpCo(s,h -C H Me )] (28 ) 4 anti 4
4 + + 90 2.7.1 Generation of [CpCo(s,h -C H Me )] (28 ) 4 anti 4
+ 4 94 2.7.2 Deprotonation of 28 by Et N and Formation of CpCo[h -C H Me (CH )] (35) 3 4 anti 3 2
96 2.8 Reactions of (2–5h)-3,4-Dimethylhexa-1,2,4-triene ? omplexes 25 and 35
2.8.1 Protonation of 25 and 35 with CF CO H 96 3 2
2.8.2 Reaction of 25 and 35 with [C H NH]Tf 98 5 5