1 A Density Functional Study on Activation and Ion-Pair Formation in Group IV Metallocene and Related Olefin Polymerization Catalysts Mary S.W. Chan,

Slides:

Advertisements

Similar presentations

1 Density Functional Theory Examination of the C-H Activation Step of the Catalytica Methane Activation Reaction: Pyrimidine Ligand Protonation, Chloride.

Advertisements

A Valence Bond Analysis of Olefin Polymerization Catalysts Timothy K. Firman and Tom Ziegler.

Towards More Realistic Molecular Modeling of Homogenous Catalysis: Combined QM/MM and ab initio Molecular Dynamics Investigations Tom K. Woo, Peter M.

Bis-amides and Amine Bis-amides as Ligands for Olefin Polymerization Catalysts Based on V(IV), Cr(IV) and Mn(IV). A Density Functional Theory Study Timothy.

A Density Functional Study of the Effect of Counterions and Solvents on the Activation of the Olefin Polymerisation Catalyst (1,2Me 2 Cp) 2 ZrMe + Kumar.

Thermodynamics of Oxygen Defective Magnéli Phases in Rutile: A First Principles Study Leandro Liborio and Nicholas Harrison Department of Chemistry, Imperial.

Ionic Conductivity And Ultrafast Solvation Dynamics Biman Bagchi Indian Institute of Science Bangalore, INDIA.

Effect of supra thermal electrons on particle charge in RF sheath A.A.Samarian and S.V. Vladimirov School of Physics, University of Sydney, NSW 2006, Australia.

Chem 388: Molecular Dynamics and Molecular Modeling Continuum Electrostatics And MM-PBSA.

An image-based reaction field method for electrostatic interactions in molecular dynamics simulations Presented By: Yuchun Lin Department of Mathematics.

SOLVENT EFFECTS ON IR MODES OF (R)-3-METHYLCYCLOPENTANONE CONFORMERS: A COMPUTATIONAL INVESTIGATION Watheq Al-Basheer Physics Department - King Fahd University.

1 Density Functional Study of Neutral Salicylaldiminato Ni(II) Complexes as Olefin Polymerization Catalysts Mary Chan, Liqun Deng and Tom Ziegler Department.

Macromolecular Science and Engineering Tuesday June 1 PM MA3 Regatta Advances In Olefin Polymerization Organizer - H. Zahalka Chair - H. Zahalka 13:30-14:00.

1 Bis-amides and Amine Bis-amides as Ligands for Olefin Polymerization Catalysts Based on V(IV), Cr(IV) and Mn(IV). A Density Functional Theory Study Timothy.

Investigations on the Structures Present in a Solution of (1) 'Pure', (2) TMA (Trimethylaluminum) Containing and (3) Dimethylzirconocene (Cp 2 ZrMe 2 )

Prof. Tom Ziegler - Department of Chemistry University of Calgary-Calgary,Alberta,Canada T2N 1N4 Density Functional Theory. Approaching Chemistry from.

ACS Meeting, Chicago August 28, 2001

1 M(XCHX) 2 R + and M(XCHCHCHX) 2 R + (M=Ti,Zr ; X= NH, O, S) as olefin polymerization catalysts and the role of ligand conjugation: A Density Functional.

DFT and stochastic studies on the influence of the catalyst structure and the reaction conditions on the polyolefin microstructure Artur Michalak a,b and.

1 A Combined Quantum Mechanical and Statistical Mechanical Study of the Equilibrium of Trimethylaluminum (TMA) and Oligomers of (AlOCH 3 ) n Found in Methylaluminoxane.

First-principle MD studies on the reaction pathways at T=0K and at finite temperatures Artur Michalak a,b and Tom Ziegler a a Department of Chemistry,

A Density Functional Study of the Insertion Mechanism in MAO (Methylaluminoxane)- Activated, Cp 2 ZrMe 2 -Catalyzed Olefin Polymerization Eva Zurek, Tom.

Modeling MAO (Methylalumoxane ) Eva Zurek, Tom Woo, Tim Firman, Tom Ziegler University of Calgary, Department of Chemistry, Alberta, Canada, T2N-1N4.

A density functional study on polymerization processes catalyzed by Pd(II) complexes Artur Michalak and Tom Ziegler* University of Calgary; Calgary, Alberta,

Theoretical studies on the polymerization and copolymerization processes catalyzed by the late transition metal complexes Artur Michalak a,b and Tom Ziegler.

1 A Combined Density Functional Theory and Molecular Mechanics Study of Iron(II)- and Cobalt(II)- Based Catalysts for the Polymerization of Ethylene Liqun.

1 [Ni 0 L]-catalyzed cyclodimerization of butadiene: A computational study based on the generic [Ni 0 (butadiene) 2 PH 3 ] catalyst. Sven Tobisch and Tom.

Stochastic Simulations of Polymer Growth and Isomerization in Ethylene/  -Olefin Polymerization Catalyzed by Late Transition Metal Complexes - - From.

1 A Density Functional Study of the Competing Processes Occuring in Solution during Ethylene Polymerisation by the Catalyst (1,2Me 2 Cp) 2 ZrMe + Kumar.

Polymerization-Catalysts with d n -Electrons (n = 1 – 4): A possible promising Cr-d 2 Catalyst Rochus Schmid and Tom Ziegler University of Calgary, Department.

A Theoretical Investigation of the Dormant & Active Species in MAO (Methylaluminoxane)- Activated, Cp 2 ZrMe 2 -Catalyzed Olefin Polymerization Eva Zurek,

A Theoretical Investigation of the Structure and Function of MAO (Methylaluminoxane) Eva Zurek, University of Calgary.

KINETICS OF THE SELF-REACTION OF NEOPENTYL RADICALS Ksenia A. Loginova and Vadim D. Knyazev Department of Chemistry, The Catholic University of America,

Chain Propagation for Polyethylene and Polypropylene Polymerization with Late Metal Homogeneous Catalysts Dean M. Philipp, Richard P. Muller, and William.

More Realistic Molecular Modelling of Catalytic Processes with the Combined QM/MM and ab initio Molecular Dynamics Method Tom Woo §, Tom Ziegler Department.

A Static and Dynamic Density Functional Theory Study of Methanol Carbonylation Minserk Cheong, a Rochus Schmid, b and Tom Ziegler c a Department of Chemistry,

Density Functional Theory Study of the Polymerization of Ethylene on the Classical TiCl 4 /MgCl 2 Ziegler-Natta Catalyst Michael Seth and Tom Ziegler University.

1 Macromolecular Science and Engineering Wednesday June 2 MA3 Regatta Advances In Olefin Polymerization Organizer - H. Zahalka Chair - J. Soares 14:00-14:30.

Covalent Bonding Skeleton Diagrams Edward A. Mottel Department of Chemistry Rose-Hulman Institute of Technology.

Infrared spectroscopy of Li(methylamine) n (NH 3 ) m clusters Nitika Bhalla, Luigi Varriale, Nicola Tonge and Andrew Ellis Department of Chemistry University.

Conclusions The spin density surfaces of the antiferromagnetic ground states demonstrate opposite spins at the ends, and alternating spins along the length.

Main-Group Cocatalysts for Olefin Polymerization

A method to rapidly predict the injection rate in Dye Sensitized Solar Cells Daniel R. Jones and Alessandro Troisi PG Symposium 2009.

Reorientation of ions in contact ion pairs as a factor increasing the intensity of outer-sphere charge transfer bands Tolstykh, MV; Birin, KP ; Nelyubina,

Chapter 1 An Introduction to Organic Reactions Nabila Al- Jaber

1 Li Xiao and Lichang Wang Department of Chemistry & Biochemistry Southern Illinois University Carbondale The Structure Effect of Pt Clusters on the Vibrational.

Effect of Aromatic Interactions on Flavin's Redox Potential: A Theoretical Study Michael A. North and Sudeep Bhattacharyya Department of Chemistry, University.

Modelling Metal Foam Formation in Helium Nanodroplets David McDonagh, The Centre for Interdisciplinary Science Project Supervisor: Professor Andrew Ellis,

Electrostatic Effects in Organic Chemistry A guest lecture given in CHM 425 by Jack B. Levy March, 2003 University of North Carolina at Wilmington (subsequently.

Water layer Protein Layer Copper center: QM Layer Computing Redox Potentials of Type-1 Copper Sites Using Combined Quantum Mechanical/Molecular Mechanical.

Photoelectron Spectroscopy Study of Ta 2 B 6 − : A Hexagonal Bipyramidal Cluster Tian Jian, Wei-Li Li, Constantin Romanescu, Lai-Sheng Wang Department.

2 Outline Background Objective Quantum Chemical Analysis Combinatorial Study and Data Mining Conclusion.

Substitution reactions at octahedral complexes:

Theoretical Investigation of the M + –RG 2 (M = Alkaline Earth Metal; RG = Rare Gas) Complexes Adrian M. Gardner, Richard J. Plowright, Jack Graneek, Timothy.

TURBOMOLE Lee woong jae.

Role of Theory Model and understand catalytic processes at the electronic/atomistic level. This involves proposing atomic structures, suggesting reaction.

Metallocene based Polymerization

The Search for an Observable Helium Complex Adrian M. Gardner, Timothy G. Wright and Corey J. Evans.

1 Modeling of the Counterion, B(C 6 F 5 ) 3 CH 3 -, with the QM/MM Method and its Application to Olefin Polymerization Kumar Vanka and Tom Ziegler University.

Main Title Manori Perera 1 and Ricardo Metz University of Massachusetts Amherst 64 th International Symposium on Molecular Spectroscopy June 25th, 2009.

Studies on DMSOR. A Theoretical Approach Elizabeth Hernandez-Marin October 2, 2009.

Applications of ETS-NOCV method in description of various types of chemical bonds Mariusz P. Mitoraj Jagiellonian University Cracow, Poland Department.

These are at 326 cm -1 and 620 cm -1 which are respectively assigned to the ν(C1N1N2) and imidazole ring deformation mode. The phenyl ring breathing mode.

The National Centre for Sensor Research Density functional theory investigation of ruthenium polypyridyl complexes incorporating 1,2,4-triazole Introduction.

Carbon Nanotube with Square Cross-section: An Ab Initio Investigation

Structure of Presentation

Carbon Nanotube Diode Design

A theoretical investigation to evaluate structural and conformational effects of ligands in transition metal complexes useful for the preparation of ultra-high.

A Computational Study of the Solvation Chemistry of Zr4+ Cation

Wang and Truhlar – NSF research, Feb. 2011

Presentation transcript:

1 A Density Functional Study on Activation and Ion-Pair Formation in Group IV Metallocene and Related Olefin Polymerization Catalysts Mary S.W. Chan, Kumar Vanka, Cory C. Pye and Tom Ziegler Department of Chemistry, University of Calgary Calgary, Alberta Canada T2N 1N4

2Introduction Activation of the Precatalyst by B(C 6 F 5 ) 3 Yang, X.; Stern, C.L.; Marks, T. J. J.Am. Chem. Soc. 1994, 116, Metallocenes are not very effective as polymerization catalysts by themselves. They require activation by a Lewis acid such as B(C 6 F 5 ) 3. The product of this reaction was characterized experimentally and crystal structures like the one shown on the right was used as model geometry for computational studies

3Introduction Possible Reactions of the Contact Ion-Pair A: activation of the precatalyst B:dissociation into infinitely separated ions C:insertion of a solvent molecule in the contact ion-pair D:insertion of an olefin molecule in the contact ion-pair E:dissociation of solvent separated ion-pair F: dissociation of olefin separated ion-pair

4 Major Sections Mono- cyclopentadienyl Constrained Geometry Bis- cyclopentadienyl M = Ti or Zr R = methyl group à Reactions of the contact ion-pair à Activation of various catalyst precursors by the co-catalyst B(C 6 F 5 ) 3 Areas for In-depth Study Catalyst Systems for In-depth Study

5 Computational Details The density functional theory calculations were carried out using the Amsterdam Density Functional (ADF) program version Geometry optimizations were carried out using the local exchange-correlation potential of Vosko et al. 2 A triple-zeta basis set was used to describe the outer most valence orbitals for the titanium and zirconium whereas a double- zeta basis set was used for the non-metals. The frozen-core approximation was used to treat the core orbtials for all atoms. The gas phase energy differences between stationary points were calculated by augmenting the LDA energy with Predew and Wang’s non-local correlations and exchange corrections. 3 The energy differences in solution was corrected from the gas phase energies by accounting for the solvation energy calculated by the Conductor-like Screening Model (COSMO). 4 The solvation energy calculations were carried out with a dielectric constant of 2.38 to represent toluene as the solvent. The charge distribution study was carried out by the Hirshfeld analysis (a) Baerends, E.J.; Ellis, D.E.; Ros, P. Chem. Phys. 1973, 2, 41. (b) Baerends, E.J.; Ros, P. Chem. Phys. 1973, 2, Vosko, S.H.; Wilk, L.; Nusair, M. Can. J. Phys. 1980, 58, Perdew, J. P. Phys. Rev. B 1992, 46, Pye, C.C.; Zielger T. Theor. Chem. Acc (DOI /s m184, in press pulbished online March 16, 1999). 5. Hirshfeld, F.L. Theoret. Chim. Act. 1977, 44, 129.

6 Enthalpy Change of Methide Abstraction ∆H M = Ti kcal/mol M = Zr kcal/mol ∆H M = Ti kcal/mol M = Zr kcal/mol ∆H M = Ti kcal/mol M = Zr kcal/mol Activation by a -catalyst Activation by a Co-catalyst

7 Activation by a Co-catalyst Charge Analysis of Ligands and Functional Groups in the Neutral Precursor and Ion-Pair + cyclopentadienyl 0.02 Ti 0.41 methyl-0.15 methyl-0.13 B 0.11 C 6 F C 6 F C 6 F cyclopentadienyl 0.13 Ti 0.43 methyl-0.07 Methyl-0.07  -methyl-0.03 B-0.01 C 6 F C 6 F C 6 F Flow of electron density from cyclopentadienyl and methyl ligand to the boron and pentafluorophenyl groups is observed.

8 Activation by a Co-catalyst Effect of Alkyl Substitution on the Constrained Geometry Catalyst ∆H ∆HTotalTotalChange in R gas phase COSMOCharge inCharge inCharge (kcal/mol)(kcal/mol)NeutralIon-PairDensity H Methyl Isopropyl tert-Butyl

9 Activation by a Co-catalyst Effect of Methyl Substitution on Cp Rings ∆H (kcal/mol) Substitution on Cp gas phase COSMOExperimental a H ,2-Dimethyl Pentamethyl a Obtained from: Deck, P.A.; Beswick, C.L.; Marks, T.J. J. Chem. Soc. 1998, 120, 1772.

10 Reactions of the Contact Ion-Pair Toluene Complexed Ions and Ion-Pairs from the CpZrMe 3 Precursor

11 Reactions of the Contact Ion-Pair Toluene Complexed Ions and Ion-Pairs from the H 2 SiCp(NH)ZrMe 2 Precursor

12 Reactions of the Contact Ion-Pair Toluene Complexed Ions and Ion-Pairs from the Cp 2 ZrMe 2 Precursor

13 Reactions of the Contact Ion-Pair Olefin Complexed Ions and Ion-Pairs from the CpZrMe 3 Precursor

14 Reactions of the Contact Ion-Pair Olefin Complexed Ions and Ion-Pairs from the H 2 SiCp(NH)ZrMe 2 Precursor

15 Reactions of the Contact Ion-Pair Olefin Complexed Ions and Ion-Pairs from the Cp 2 ZrMe 2 Precursor

16 Reactions of the Contact Ion-Pair Initial Stages of Polymerization for CpMMe 3 and H 2 SiCp(NH)MMe 2 Systems

17 Reactions of the Contact Ion-Pair Initial Stages of Polymerization for Cp 2 MMe 2 Systems

18 Future Work Search for the structure of resting state(s) incorporating the counter ion Molecular dynamics simulation of olefin uptake and insertion from the contact ion-pair

19 Electronic factors play a predominant role in determining the enthalpy change of methide abstraction to form a contact ion-pair. Mechanism of olefin complexation dependant on the structure of the catalyst precursor and solvent. Mono-cyclopentadienyl and constrained geometry catalysts show a strong tendency to co-ordinate with toluene The steric bulk of the bis-cyclopentadienyl catalysts prevent optimal co- ordination with toluene and makes olefin complexation more favorable. Conclusions Acknowledgement This investigation was supported by the Natural Science and Engineering Research Council of Canada (NSERC) and by Novacor Research and Technology of Calgary.