1 macromolecular science and engineering wednesday june 2 ma3 regatta advances in olefin...

1

Macromolecular Science and Engineering

Wednesday June 2 MA3 Regatta Advances In Olefin Polymerization

Organizer - H. Zahalka Chair - J. Soares

14:00-14:30 00995 A Density Functional Study on Ion-Pair Formation in Group 4 Metallocene and Related Olefin Polymerization CatalystsZiegler T., Chan M., Vanka K., Pye C.

2

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 CalgaryCalgary, Alberta Canada T2N 1N4

Ion-Pair FormationCH3

Zr

CH3

CH3

CH3

CH3

CH3

B

C6

F5

C6F5

C6F5

CH3

Zr

CH3

CH3

CH3

CH3

CH3

B

C6F5

C6F5

C6F5

Ion-Pair Formation

P.Deck,T.Marks, J.Am.Chem.Soc. 1995,117,6128-6129

ΔH dr . = -23.8 / , calc KCal molΔHdr . = -24.2 /exp KCal mol

F

F

C

F

C

C

C

C

C

F

C

F

F

C

C

F

C

C

F

C

C

B

C

C

C

C

C

Zr

C

C

CC

F

C

C

C

C

C

F

C

C

F

C

C

F

C

C

C

F

F

F

5

Major SectionsMajor Sections

Mono-cyclopentadienyl

ConstrainedGeometry

Bis-cyclopentadienyl

MR R

RNR

RRR2Si M R

RM M = Ti or Zr

R = methyl group

Reactions of the contact ion-pair

Activation of various catalyst precursors by the co-catalyst B(C6F5)3

Areas for In-depth Study

Catalyst Systems for In-depth Study

6

Enthalpy Change of Methide Abstraction

H3C CH3H3C

B

C6F5

C6F5C6F5

H3C

CH3CH3

B

C6F5

C6F5

C6F5+M

N

CH3CH3

H2Si

H

B

C6F5

C6F5C6F5

N

CH3CH3

H2Si

HB

C6F5

C6F5

C6F5+M

M

CH3CH3

B

C6F5

C6F5C6F5 CH3

CH3B

C6F5

C6F5

C6F5+M

M

∆H M = Ti -12.2 kcal/mol M = Zr -14.9 kcal/mol

∆H M = Ti -14.4 kcal/mol M = Zr -17.5 kcal/mol

∆H M = Ti -16.3 kcal/mol M = Zr -19.1 kcal/mol

Activation by a Activation by a Co-catalyst-catalyst

7

Activation by a Co-catalystActivation by a Co-catalyst

Charge Analysis of Ligands and Functional Groups in the Neutral Precursor and Ion-Pair

+

Cyclopentadienyl 0.02Ti 0.41methyl -0.15methyl -0.15methyl -0.13

B 0.11C6F5 -0.04C6F5 -0.03C6F5 -0.04

Cyclopentadienyl 0.13Ti 0.43methyl -0.07Methyl -0.07-methyl -0.03B -0.01C6F5 -0.09C6F5 -0.13C6F5 -0.15

C

C

C

C

Ti

C

CC

C

F

F

C

F

C

C

C

C

F

C

FF

FC

B

CC

C

C

F

F

C

C

C

C

Ti

C

C

C

C

F

C

C

F

C

C

C

C

F

F

C

F

FF

F

C

F

C

C

C

C

F

F

C

F

C

C

B

C

F

C

F

C

C

F

F

C

C

F

F

C

C

F

C

C

F

F

8

Activation by a Co-catalyst

N

CH3

CH3H2Si

R

B

C6F5

C6F5C6F5

N

CH3

CH3H2Si

RB

C6F5

C6F5

C6F5+TiTi

Effect of Alkyl Substitution on the Constrained Geometry Catalyst

∆H ∆H Total Total Change in R gas phase COSMO Charge in Charge in Charge

(kcal/mol) (kcal/mol) Neutral Ion-Pair Density

H -13.9 -14.4 -0.21 -0.17 0.04

Methyl -16.1 -16.4 -0.19 -0.13 0.06

Isopropyl -16.9 -17.0 -0.18 -0.12 0.06

tert-Butyl -18.4 -18.0 -0.19 -0.10 0.09

9

Activation by a Co-catalystActivation by a Co-catalyst

Effect of Methyl Substitution on Cp Rings

CH3

CH3

B

C6F5

C6F5C6F5

CH3

CH3

B

C6F5

C6F5

C6F5+Zr

Zr

∆H (kcal/mol) ∆H (kcal/mol) Substitution on Cp gas phase COSMO Experimentala

H -19.1 -19.1 -23.1

1,2-Dimethyl -23.8 -24.0 -24.3

Pentamethyl -27.5 -27.8 -36.7

aObtained from: Deck, P.A.; Beswick, C.L.; Marks, T.J. J. Chem. Soc. 1998, 120, 1772.

Co-catalyst Engineering

Co-catalyst ΔHdr . calc ΔHdrexp

/ /KCal mol KCal mol (B C6F5)3 -23.8 -24.2 (B C6F5)2(C6H3F2) -21.5 -18.7 (B C6F5)2 (C6H5) -18.3 -14.8 (B C6F5)2{C6H3(CH3)2} -18.0 -10.8 (B C6H5)3 -6.7 -- . . , . . , . . , . . . ,P A Deck C L Beswick T J Marks J Am Chem Soc

1998,120,1772-1784

5

10

15

20

25

-DelHdr

0 4 8 12 16 20

No. Of Fluorine Atoms

Plot Of -DelHdr vs No. of Fluorine Atoms

Charge AnalysisFunctional Group Δ . Hdrcalc Total Charge

/KCal mol C6F5 -23.8 -0.453

C6H3F2 -21.3 -0.3296

C6H5 -18.3 -0.2963

C6H3(CH3)2 -18.0 -0.2894

13

New Cocatalysts

L.Li, T.Marks, Organometallics 1998, 17, 3996-4003

F

F

C

F

C

C

F

C

C

C

C

F

F

C

C

F

C

C

CB

F

C

C

F

F

C

C

C

C

F

C

F

C

C

C

F

F

F

F

C

C

F

C

C

F

C

C

C

F

C

F

F

14

MAO as Co-catalyst

C

C

C

C

C

Al O

AlO

C

C

C

C

Zr

2.158Å

4.598Å Al

O

C

C

C

O

C

AlC

C

C

O

C

Al

C

C

OAl

C

C

C

C.J.Harlan, S.G.Bott, A.R.Barron,

J.Am.Chem.Soc. 1995,117,6465-6474

15

Co-catalyst ΔHdr . calc ΔHdrexp

( / ) ( / )KCal mol KCal mol(B C10F7)3 -25.8 -

-15.2 -10.9MAO -22.3 -MBO

AlMe3 -6.7 -(Al C6F5)3 -30.8 -

16

Ion-Pair DissociationCH3

Zr

CH3

CH3

CH3

CH3

CH3

B

C6F5

C6F5

C6F5

CH3

Zr

CH3

CH3

CH3

CH3

B

C6

F5 C6F5

CH3

C6F5

17

Ion-pair Dissociation Energies

Co-catalyst ΔHdr . -calc ΔHips . -calc ΔHipsexp#

/ / /KCal mol KCal mol KCal mol (B C6F5)3 -23.8 -38.0 -24.0(B C10F7)3 -25.8 -43.6 -

-15.2 -57.0 -MAO -22.2 -46.9 -MBOAlMe3 -6.7 -69.2 - (Al C6F5)3 -30.0 -48.3 -

18

Influence of Solvent

• Implicitly included through Single PointCalculations Using COSMO

• Explicitly included through addition of a singlesolvent molecule coordinated to the cation

19

Ion-Pair Dissociation

C6

F5

CH3

Zr

CH3

CH3

CH3

CH3

CH3

B

C6F5

C6F5

C6F5

CH3

Zr

CH3

CH3

CH3

CH3

B

C6F5

CH3

C6F5

CH3

CH3

Solvent Separated Ion-Pair

20

Influence Of Solvent

η2−Coordinated

F

F

C

C

F

F

C

F

C

F

C

C

C

C

F

F

C

C

C

B

C

C

C

C

C

F

C

C

C

C

CC

CF

F

C

C

F

Zr

C

C

C

C

C

C

C

C

C

F

C

C

CC

C

C

F

C

F

21

Influence Of Solvent

η1coordinated

F

F

C

C

F

C

C

F

C

C

C

C

CC

F

C

C

C

C

F

F

B

C

C

C

F

CZr

F

C

C

C

Cl

C

C

C

F

C

C

C

C

C

CC

F

C

C

F

C

C

F

C

F

C

C

C F

C

22

Solvent -ΔHips . -calc ΔHipsexp#

/ /KCal mol KCal mol (η2)C6H5CH3 -18.7 -24.2 (η2)C6D5 -15.4 -11.0Cl (η1)C6D5 -15.1 -11.0Cl (η2)C6D4Cl2 -13.8 -12.0 (η1)C6D4Cl2 -15.9 -12.0

. . , . . , . . ,P A Deck C L Beswick T J Marks. . . ., 1998,120,1772-1784J Am Chem Soc

23

Competing Reactions

CH3

Zr

CH3

CH3

CH3

Solvent

Precatalyst

Co-catalyst

Monomer

CH3

24

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

Zr

C

C

ZrC

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

25

Species ΔHdr

/KCal mol(1,2-Me2 )Cp 2ZrMe+-- (B C6F5)3 -9.9(1,2-Me2 )Cp 2ZrMe+--C6H5CH3 -10.2(1,2-Me2 )Cp 2ZrMe+--AlMe3 -25.4(1,2-Me2 )Cp 2ZrMe+--(1,2Me2 )Cp 2ZrMe2 -25.8

26

Work In Progress

Search for improved co-catalysts :

(i) Diborane Systems

L.Jia,X.Yang,C.Stern,T.J.Marks,

Organometallics,13,3755-37557

F

F

F

C

C

F

C

F

F

C

C

F

C

C

F

C

C

F

F C

F

F

BB

C

F

C

C

C

C

CC

F

C

C

C

C

F

F

C

C

F

C

F

F

C

C

C

C

F

27

Work In Progress

(ii) Modified MAO/MBO Structures

(iii) New Anionic systems- Carboranes,

M(OTeF5)nm- etc.

C

C

O

Al

Al

O

C

Al

O

O

Al

C

28

Work In Progress

PCH3

CH 3

Zr

CH 3

CH 3

CH 3

Solvent

Precatalyst

Monomer

29

IntroductionIntroduction

Possible Reactions of the Contact Ion-Pair{L}M

solvent complexed cation

Sol

solvent separated ion-pair

contact ion-pair

co-ordinatively unsaturated cation

olefin separated ion-pair

Me

{L}MMe

{L}MMe

{L}MMe

{L}MMe

{L}MMe

+

+

{L}M

+

Me

Me

olefin complexed cation

+ A

A

B

CD

EF

MeA

MeA

MeASol

MeA

precatalyst

MeA

MeA

30

-1.7 kcal/mol (-4.3)

-6.3 kcal/mol (3.4)

20.4 kcal/mol (50.5)

µ-Me contact ion-pair

solvated ion-pair

toluene separated ion-pair

toluene complexed cation

MeB(C6F5)3-+

+ CH3C6H5

Reactions of the Contact Ion-PairReactions of the Contact Ion-Pair

Toluene Complexed Ions and Ion-Pairs from the CpZrMe3 Precursor

C

C

C

C

C

C

C

C

ZrC

C

C

C

C

C

F

F

C

C

F

C

F

C

F

F

C

C

C

C

F

F

C

C

B

F

C

C

C

C

C

C

C

F

Zr

C

F

C

C

C

F

F

C

C

C

C

F

F

C

F

F

C

C

F

C

C

F

C

C

C

C

C

F

F

C

F

C

C

B

C

C

C

C

C

F

C

C

C

F

C

Zr

C

C

C

C

C

F

C

F

CC

C

C

F

C

F

C

F

F

F

F

F

F

C

C

F

F

C

C

C

C

C

C

F

C

CC

C

B

C

F

C

F

F

C

F

C

C

F

C

C

C

C

C

C

CZr

C

C

C

C

C

F

C

F

C

C

C

F

31

Reactions of the Contact Ion-PairReactions of the Contact Ion-Pair

Toluene Complexed Ions and Ion-Pairs from the H2SiCp(NH)ZrMe2 Precursor

11.5 kcal/mol (48.9)

-5.2 kcal/mol (-8.8)

0.0 kcal/mol (8.4)

µ-Me contact ion-pair

solvated ion-pair toluene separated ion-pair

toluene complexed cation

MeB(C6F5)3-+

+ CH3C6H5

+

C

N

C

Si

C

C

C

Zr

C

C

C

C

C

CC

C

F

F

C

F

C

C

C

C

F

F

C

F

F

F

Si

C

N B

C

C

C

C

C

C

C

F

Zr

C

C

C

C

C

F

C

C

F

C

C

C

F

F

C

F

F

F

F

C

C

F

C

C

C

F

C

C

C

C

F

F

F

C

C

F

B

C

N

C

C

F

Si

C

C

C

C

C

C

C

C

C

Zr

C

F

C

F

C

C C

F

F

C

C

C

F

C

F

C

C

F

C

C

F

C

C

C

C

Zr

C

F

C

C

C

F

C

C

C

N

Si

C

C

C

F

C

C

B

F

C

C

C

F

C

C

F

C

F

C

F

C

C

C

C

F

C

F

F

F

F

32

17.1 kcal/mol (33.4)

11.0 kcal/mol (32.5)

-2.5 kcal/mol (-4.2)

µ-Me contact ion-pair

solvated ion-pair

toluene separated ion-pair

toluene complexed cation

MeB(C6F5)3-+

+ CH3C6H5

+

Reactions of the Contact Ion-PairReactions of the Contact Ion-Pair

Toluene Complexed Ions and Ion-Pairs from the Cp2ZrMe2 Precursor

C C

C

C

C

C

C

C

CC

C

C

Zr

C

C

C

C

C

C

FC

F

F

C

CC

C

F

F

F

C

F

F

C

C

C

B

C

C

C

F

C

C

C

C

C

C

C

C

Zr

C

C

C

C

C

F

C

F

C

C

F

C

F

C

F

F

F C

F

F

C

C

C

C

F

F

C

F

C

F

C

F

C

B

C

C

C

F

C

C

C

C

C

C

CC

Zr

C

C

C

C

C

F

C

F

C

F

CC

F

C

C

C

F

C

C

F

C

C

C

FC

F

F

C

CC

C

F

F

C

F

F

C

B

F

C

C

C

C

C

C

F

C

CC

C

C

C

C

C

C

F

C

F

C

C

C

F

C

C

C

F

C

C

Zr

C

F

C

F

C CC

C

33

Reactions of the Contact Ion-PairReactions of the Contact Ion-Pair

Olefin Complexed Ions and Ion-Pairs from the CpZrMe3 Precursor

12.6 kcal/mol (20.0)

49.7 kcal/mol (94.8)

MeB(C6F5)3-

+

18.3 kcal/mol (51.9)

C2H4

µ-Me contact ion-pair

olefin separated ion-pair

olefin π-complex

co-ordinatively unsaturated cation

_

+

C2H4+

+

+

+

C

C

CC

Zr

C

CC

C

C

FF

C

C

C

C

FCCF

C

C

C

Zr

F

C

F

C

C

F

C

C

F

C

BC

CC

C

C

F

C

C

C

C

F

F

C

F

C

F

C

C

F

F

F

F

C

C

F

C

F

C

F

F

C

C

C

C

F

F

C

C

B

F

C

C

C

C

C

C

C

F

Zr

C

F

C

C

C

F

F

C

C

C

C

F

F

C

C

C

C

Zr

C

C

C

C

FF

F

F

C

C

F

F

C

C

CC

C

C

C

C

F

F

C

C

F

B

C

F

F

C

C

F

C

C

F

C

C

F

F

34

Reactions of the Contact Ion-PairReactions of the Contact Ion-Pair

Olefin Complexed Ions and Ion-Pairs from the H2SiCp(NH)ZrMe2 Precursor

10.0 kcal/mol (16.1)

49.8 kcal/mol (93.7)

20.0 kcal/mol (54.1)

µ-Me contact ion-pair

co-ordinatively unsaturated cation

olefin π-complex

olefin separated ion-pair

C2H4+ +

_+

MeB(C6F5)3-+

+

C2H4+

FF

F

F

C

C

F

F

C

C

CC

C

C

C

C

F

F

C

C

F

B

C

F

F

C

C

F

C

C

F

C

C

F

F

C

C

N

Si

C

Zr

C C

C C

C

F

C

F

C

C C

Si

N

C

FC

C

Zr

C

C

FC

F

C

C C

C

F

F

C

C

FB

C

C

C

C

F

C

C

C

F

C

C

F

F

C

C

F

F

F

F

F

C

F

C

C

C

C

F

F

C

F

F

F

Si

C

N B

C

C

C

C

C

C

C

F

Zr

C

C

C

C

C

F

C

C

F

C

C

C

F

F

C

F

F

C

C

N

C

Zr

Si

C

C

C

35

Reactions of the Contact Ion-PairReactions of the Contact Ion-Pair

Olefin Complexed Ions and Ion-Pairs from the Cp2ZrMe2 Precursor

48.5 kcal/mol (88.5)

20.4 kcal/mol (57.5)

8.2 kcal/mol (9.5)

co-ordinatively unsaturated cation

µ-Me contact ion-pair

olefin π-complex

olefin separated ion-pair

C2H4+ +

_

C2H4+

+

MeB(C6F5)3-+

+

FF

F

F

C

C

F

F

C

C

CC

C

C

C

C

F

F

C

C

F

B

C

F

F

C

C

F

C

C

F

C

C

F

F

C

C

C

C

C

Zr

C

C C

C

C

C

C

C

F

F

F

C

F

C

C F

FC

C

C

F

C

C C

CC

C

C

FB C F

C

C

CC F

FC

C

C

C

Zr

F

C

C

C

C

C

C

CC

F

C

C

F

F

FC

F

F

C

CC

C

F

F

F

C

F

F

C

C

C

B

C

C

C

F

C

C

C

C

C

C

C

C

Zr

C

C

C

C

C

F

C

F

C

C

F

C

F

C

F

F

C

C

C

C

C

CZr

C

C

C

C

C

36

Reactions of the Contact Ion-PairReactions of the Contact Ion-Pair

Initial Stages of Polymerization for CpMMe3 and H2SiCp(NH)MMe2 Systems

H3C

CH3CH3

B

C6F5

C6F5

C6F5

CH3B

C6F5

C6F5

C6F5

CH3

M

H3C

H3C

CH3B

C6F5

C6F5

C6F5

M

H3CH3C

CH2

CH2

H3C

CH3

CH3B

C6F5

C6F5

C6F5

CH3

M

M

H3C

CH2CH2CH3

CH3B

C6F5

C6F5

C6F5M

contact ion-pair

olefin separated ion-pair

toluene separated ion-pair

solvated ion-pair

olefin inserted product

37

Reactions of the Contact Ion-PairReactions of the Contact Ion-Pair

Initial Stages of Polymerization for Cp2MMe2 Systems

CH3CH3

B

C6F5

C6F5

C6F5

CH3B

C6F5

C6F5

C6F5

CH3

CH3

CH3B

C6F5

C6F5

C6F5

CH3

CH3B

C6F5

C6F5

C6F5CH2

CH2

M

M

M

M

CH2CH2CH3

CH3B

C6F5

C6F5

C6F5M

CH3

CH3

olefin separated ion-pair

olefin inserted product

contact ion-pair

toluene separated ion-pair

solvated ion-pair

38

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

39

Work in ProgressWork in Progress

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

F

F

C

C

F

C

C

F

C

C

C

CC

F

C

F

F

C

C

F

C

F

B

C

C

C

C

C

Zr C

C

C

C

C

C

C

C

F

C

F

F

C

F

F

C

C

F

C

C

C

40

Future WorkFuture Work

To study the influence of the counter ion on the propagation steps of the polymerization process

To study the influence of the counter ion on chain termination steps of the polymerization process

To study the role of the counter ion with other catalysts precursors such as the Brookhart or the McConville systems

To study the influence of other solvents (non-aromatic) on ion-pair formation and dissociation

To design new precatalysts and co-catalysts systems

NSERC

PRF Novacor

Dr. Mary Chan

Kumar Vanka

Dr. Cory Pye

42

43

Computerson benchesall linkedtogether

Cobalt

44