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DFT and stochastic studies on the influence
of the catalyst structure and the reaction conditions
on the polyolefin microstructure
DFT and stochastic studies on the influence
of the catalyst structure and the reaction conditions
on the polyolefin microstructure
Artur Michalaka,b and Tom Zieglera
aDepartment of Chemistry,
University of Calgary,
Calgary, Alberta, Canada
bDepartment of Theoretical Chemistry
Jagiellonian University
Cracow, Poland
Artur Michalaka,b and Tom Zieglera
aDepartment of Chemistry,
University of Calgary,
Calgary, Alberta, Canada
bDepartment of Theoretical Chemistry
Jagiellonian University
Cracow, Poland
April 18, 2023April 18, 2023
Ethylene polymerization mechanismEthylene polymerization mechanism
-agostic
-complex
+ ethylene
-agostic
-agosticinsertion
n
Propylene:
n
Etylene:
333 methyl branches / 1000 C atoms
Linear chain
-olefin polymerization mechanism-olefin polymerization mechanism
-olefin polymerization mechanism-olefin polymerization mechanism
n
Propylene:
n
Etylene:
333 methyl branches / 1000 C atoms
Linear chain
Observed: up to 130 branches / 1000 C
Observed: 210 - 333 branches / 1000 C
Diimine catalystsDiimine catalysts
n
Propylene:
n
Etylene:
333 methyl branches / 1000 C atoms
Linear chain
Observed: up to 130 branches / 1000 C
Observed: 210 - 333 branches / 1000 C
n
Propylene:
n
Propylene:
n
Etylene:
n
Etylene:
333 methyl branches / 1000 C atoms
Linear chain
Observed: up to 130 branches / 1000 C
Observed: 210 - 333 branches / 1000 C
CCC
CC
CC
C
C
CC
C
CC
C
CC
C
C
CC
C
N CNC CC
C
C
CCC C
CC
Pd
CC
Diimine catalystsDiimine catalysts
Influence of olefin pressure on the polymer structurehigh p - linear structureslow p - hyperbranched structures
Pd – No. of branches independent of pNi – No. of braches influenced by p
n
Propylene:
n
Etylene:
333 methyl branches / 1000 C atoms
Linear chain
Observed: up to 130 branches / 1000 C
Observed: 210 - 333 branches / 1000 C
n
Propylene:
n
Propylene:
n
Etylene:
n
Etylene:
333 methyl branches / 1000 C atoms
Linear chain
Observed: up to 130 branches / 1000 C
Observed: 210 - 333 branches / 1000 C
Models for the catalyst:Models for the catalyst:
1) generic system: R = H; Ar = H1) generic system: R = H; Ar = H
2) a variety of systems with different substituents:
• R = H; Ar = Ph• R = H; Ar = Ph (Me)2
• R = H; Ar = Ph (i-Pr)2
• R = Me; Ar = H• R = Me; Ar = Ph (Me)2
• R = Me; Ar = Ph (i-Pr)2
• R2 = An; Ar = H• R2 = An; Ar = Ph (i-Pr)2
2) a variety of systems with different substituents:
• R = H; Ar = Ph• R = H; Ar = Ph (Me)2
• R = H; Ar = Ph (i-Pr)2
• R = Me; Ar = H• R = Me; Ar = Ph (Me)2
• R = Me; Ar = Ph (i-Pr)2
• R2 = An; Ar = H• R2 = An; Ar = Ph (i-Pr)2
CC
NN
Pd
R R
Ar Ar
+
CC
NN
Pd
R R
Ar Ar
+
CC
NN
Pd
Models for the catalyst:Models for the catalyst:
1) generic system: R = H; Ar = H1) generic system: R = H; Ar = H
2) a variety of systems with different substituents:
• R = H; Ar = Ph• R = H; Ar = Ph (Me)2
• R = H; Ar = Ph (i-Pr)2
• R = Me; Ar = H• R = Me; Ar = Ph (Me)2
• R = Me; Ar = Ph (i-Pr)2
• R2 = An; Ar = H• R2 = An; Ar = Ph (i-Pr)2
2) a variety of systems with different substituents:
• R = H; Ar = Ph• R = H; Ar = Ph (Me)2
• R = H; Ar = Ph (i-Pr)2
• R = Me; Ar = H• R = Me; Ar = Ph (Me)2
• R = Me; Ar = Ph (i-Pr)2
• R2 = An; Ar = H• R2 = An; Ar = Ph (i-Pr)2
CC
NN
Pd
R R
Ar Ar
+
CC
NN
Pd
R R
Ar Ar
+
CC
CCCC
CNN CCC
CCC C
Pd
Models for the catalyst:Models for the catalyst:
1) generic system: R = H; Ar = H1) generic system: R = H; Ar = H
2) a variety of systems with different substituents:
• R = H; Ar = Ph• R = H; Ar = Ph (Me)2
• R = H; Ar = Ph (i-Pr)2
• R = Me; Ar = H• R = Me; Ar = Ph (Me)2
• R = Me; Ar = Ph (i-Pr)2
• R2 = An; Ar = H• R2 = An; Ar = Ph (i-Pr)2
2) a variety of systems with different substituents:
• R = H; Ar = Ph• R = H; Ar = Ph (Me)2
• R = H; Ar = Ph (i-Pr)2
• R = Me; Ar = H• R = Me; Ar = Ph (Me)2
• R = Me; Ar = Ph (i-Pr)2
• R2 = An; Ar = H• R2 = An; Ar = Ph (i-Pr)2
CC
NN
Pd
R R
Ar Ar
+
CC
NN
Pd
R R
Ar Ar
+
C
CC
C
CCCC
CNN CCC
CCC C
C
Pd
C
Models for the catalyst:Models for the catalyst:
1) generic system: R = H; Ar = H1) generic system: R = H; Ar = H
2) a variety of systems with different substituents:
• R = H; Ar = Ph• R = H; Ar = Ph (Me)2
• R = H; Ar = Ph (i-Pr)2
• R = Me; Ar = H• R = Me; Ar = Ph (Me)2
• R = Me; Ar = Ph (i-Pr)2
• R2 = An; Ar = H• R2 = An; Ar = Ph (i-Pr)2
2) a variety of systems with different substituents:
• R = H; Ar = Ph• R = H; Ar = Ph (Me)2
• R = H; Ar = Ph (i-Pr)2
• R = Me; Ar = H• R = Me; Ar = Ph (Me)2
• R = Me; Ar = Ph (i-Pr)2
• R2 = An; Ar = H• R2 = An; Ar = Ph (i-Pr)2
CC
NN
Pd
R R
Ar Ar
+
CC
NN
Pd
R R
Ar Ar
+
CC
C
CC
C
CC
C
CC
C
C
CNN CCC
CC
C
C C
CC
Pd
CC
Models for the catalyst:Models for the catalyst:
1) generic system: R = H; Ar = H1) generic system: R = H; Ar = H
2) a variety of systems with different substituents:
• R = H; Ar = Ph• R = H; Ar = Ph (Me)2
• R = H; Ar = Ph (i-Pr)2
• R = Me; Ar = H• R = Me; Ar = Ph (Me)2
• R = Me; Ar = Ph (i-Pr)2
• R2 = An; Ar = H• R2 = An; Ar = Ph (i-Pr)2
2) a variety of systems with different substituents:
• R = H; Ar = Ph• R = H; Ar = Ph (Me)2
• R = H; Ar = Ph (i-Pr)2
• R = Me; Ar = H• R = Me; Ar = Ph (Me)2
• R = Me; Ar = Ph (i-Pr)2
• R2 = An; Ar = H• R2 = An; Ar = Ph (i-Pr)2
CC
NN
Pd
R R
Ar Ar
+
CC
NN
Pd
R R
Ar Ar
+
CC
CC
NN
Pd
Models for the catalyst:Models for the catalyst:
1) generic system: R = H; Ar = H1) generic system: R = H; Ar = H
2) a variety of systems with different substituents:
• R = H; Ar = Ph• R = H; Ar = Ph (Me)2
• R = H; Ar = Ph (i-Pr)2
• R = Me; Ar = H• R = Me; Ar = Ph (Me)2
• R = Me; Ar = Ph (i-Pr)2
• R2 = An; Ar = H• R2 = An; Ar = Ph (i-Pr)2
2) a variety of systems with different substituents:
• R = H; Ar = Ph• R = H; Ar = Ph (Me)2
• R = H; Ar = Ph (i-Pr)2
• R = Me; Ar = H• R = Me; Ar = Ph (Me)2
• R = Me; Ar = Ph (i-Pr)2
• R2 = An; Ar = H• R2 = An; Ar = Ph (i-Pr)2
CC
NN
Pd
R R
Ar Ar
+
CC
NN
Pd
R R
Ar Ar
+
CC
C
CC
C
CCCC
CNN CCC
CCC C
C
Pd
C
Models for the catalyst:Models for the catalyst:
1) generic system: R = H; Ar = H1) generic system: R = H; Ar = H
2) a variety of systems with different substituents:
• R = H; Ar = Ph• R = H; Ar = Ph (Me)2
• R = H; Ar = Ph (i-Pr)2
• R = Me; Ar = H• R = Me; Ar = Ph (Me)2
• R = Me; Ar = Ph (i-Pr)2
• R2 = An; Ar = H• R2 = An; Ar = Ph (i-Pr)2
2) a variety of systems with different substituents:
• R = H; Ar = Ph• R = H; Ar = Ph (Me)2
• R = H; Ar = Ph (i-Pr)2
• R = Me; Ar = H• R = Me; Ar = Ph (Me)2
• R = Me; Ar = Ph (i-Pr)2
• R2 = An; Ar = H• R2 = An; Ar = Ph (i-Pr)2
CC
NN
Pd
R R
Ar Ar
+
CC
NN
Pd
R R
Ar Ar
+
C
CC
C
C
CC
C
CC
C
CC
C
C
N CNC CC
CC
C
C C
CC
Pd
CC
Models for the catalyst:Models for the catalyst:
1) generic system: R = H; Ar = H1) generic system: R = H; Ar = H
2) a variety of systems with different substituents:
• R = H; Ar = Ph• R = H; Ar = Ph (Me)2
• R = H; Ar = Ph (i-Pr)2
• R = Me; Ar = H• R = Me; Ar = Ph (Me)2
• R = Me; Ar = Ph (i-Pr)2
• R2 = An; Ar = H• R2 = An; Ar = Ph (i-Pr)2
2) a variety of systems with different substituents:
• R = H; Ar = Ph• R = H; Ar = Ph (Me)2
• R = H; Ar = Ph (i-Pr)2
• R = Me; Ar = H• R = Me; Ar = Ph (Me)2
• R = Me; Ar = Ph (i-Pr)2
• R2 = An; Ar = H• R2 = An; Ar = Ph (i-Pr)2
CC
NN
Pd
R R
Ar Ar
+
CC
NN
Pd
R R
Ar Ar
+
CC
CC
C
CC
C
CC
CC
NN
Pd
Models for the catalyst:Models for the catalyst:
1) generic system: R = H; Ar = H1) generic system: R = H; Ar = H
2) a variety of systems with different substituents:
• R = H; Ar = Ph• R = H; Ar = Ph (Me)2
• R = H; Ar = Ph (i-Pr)2
• R = Me; Ar = H• R = Me; Ar = Ph (Me)2
• R = Me; Ar = Ph (i-Pr)2
• R2 = An; Ar = H• R2 = An; Ar = Ph (i-Pr)2
2) a variety of systems with different substituents:
• R = H; Ar = Ph• R = H; Ar = Ph (Me)2
• R = H; Ar = Ph (i-Pr)2
• R = Me; Ar = H• R = Me; Ar = Ph (Me)2
• R = Me; Ar = Ph (i-Pr)2
• R2 = An; Ar = H• R2 = An; Ar = Ph (i-Pr)2
CC
NN
Pd
R R
Ar Ar
+
CC
NN
Pd
R R
Ar Ar
+
CCC
CC
CC
C
C
CC
C
CC
C
CC
C
C
CC
C
N CNC CC
C
C
CCC C
CC
Pd
CC
DFT calculations:DFT calculations:
A. Michalak, T. Ziegler, "Pd-catalyzed Polymerization of Propene - DFT Model Studies", Organometallics, 18, 1999, 3998-4004.
A. Michalak, T. Ziegler, "DFT studies on substituent effects in Pd-catalyzed olefin polymerization", Organometallics, 19, 2000, 1850-1858.
Examples of results:
Ethylene insertion barrier:DFT: 16.7 kcal/molexp.: 17.4 kcal/mol
Isomerization barrier:DFT: 5.8 (6.8) kcal/molexp: 7.2 kcal/mol
C
CC
C
C
CC
C
CC
C
CC
C
C
N CNC CC
CC
C
C C
CC
Pd
CC
Substituent effect in real systemsSubstituent effect in real systems
Electronic preference Steric effect(generic system) (real systems)
alkyl complexes iso-propyl iso-propyl
olefin -complexes iso-propyl alkyl n-propyl alkyl
olefin -complexes propene ethene
propene insertion 2,1- 1,2-
Electronic preference Steric effect(generic system) (real systems)
alkyl complexes iso-propyl iso-propyl
olefin -complexes iso-propyl alkyl n-propyl alkyl
olefin -complexes propene ethene
propene insertion 2,1- 1,2-
Isomerization reactionsIsomerization reactions
0.000.00
+4.56+4.56
-3.42-3.42
0.000.00+5.84+5.84
+1.59+1.59
following1,2-insertion
following2,1-insertion
Isomerization reactionsIsomerization reactions
0.000.00
+4.56+4.56
-3.42-3.42
0.000.00+5.84+5.84
+1.59+1.59
following1,2-insertion
following2,1-insertion
Isomerization reactionsIsomerization reactions
0.000.00
+4.56+4.56
-3.42-3.42
0.000.00+5.84+5.84
+1.59+1.59
following1,2-insertion
following2,1-insertion
1 C atom attached to the catalyst:olefin capture
followed by 1,2- or 2,1-
insertion
Stochastic simulation - how it worksStochastic simulation - how it works
1 C atom attached to the catalyst:olefin capture
followed by 1,2- or 2,1-
insertion
Stochastic simulation - how it worksStochastic simulation - how it works
Primary C attached to the catalyst:1) 1 possible isomerization 2) olefin capture and 1,2- insertion3) olefin capture and 2,1- insertion4) termination
Stochastic simulation - how it worksStochastic simulation - how it works
1
2
3
4
Secondary C attached to the catalyst:1) isomerization to primary C2) isomerisation to secondary C3) olefin capture and 1,2- insertion4) olefin capture and 2,1- insertion5) termination
Stochastic simulation - how it worksStochastic simulation - how it works
Secondary C attached to the catalyst:1) isomerization to secondary C2) isomerisation to secondary C3) olefin capture and 1,2- insertion4) olefin capture and 2,1- insertion5) termination
Stochastic simulation - how it worksStochastic simulation - how it works
Secondary C attached to the catalyst:1) isomerization to primary C2) isomerisation to secondary C3) olefin capture and 1,2- insertion4) olefin capture and 2,1- insertion5) termination
Stochastic simulation - how it worksStochastic simulation - how it works
Primary C attached to the catalyst:1) isomerization to secondary C2) olefin capture and 1,2- insertion3) olefin capture and 2,1- insertion4) termination
Stochastic simulation - how it worksStochastic simulation - how it works
Primary C attached to the catalyst:1) isomerization to tertiary C2) olefin capture and 1,2- insertion3) olefin capture and 2,1- insertion4) termination
Stochastic simulation - how it worksStochastic simulation - how it works
Probablities of the eventsProbablities of the events
Basic assumption:relative probabilities (microscopic)
= relative rates (macroscopic):
Basic assumption:relative probabilities (microscopic)
= relative rates (macroscopic):
i
π j
=ri
rj
i
i∑ = 1
36
Macroscopic kinetic expressions with microscopic barriers for elementary reactions(calculated or experimental)
Macroscopic kinetic expressions with microscopic barriers for elementary reactions(calculated or experimental)
Use of macroscopic kinetic expressions allows us to discuss the effects of the reaction conditions (temperature and olefin pressure)
Use of macroscopic kinetic expressions allows us to discuss the effects of the reaction conditions (temperature and olefin pressure)
Probablities of the eventsProbablities of the events
Basic assumption:relative probabilities (microscopic)
= relative rates (macroscopic):
e.g. isomerization vs. isomerization:
isomerization vs. insertion:
etc.
Basic assumption:relative probabilities (microscopic)
= relative rates (macroscopic):
e.g. isomerization vs. isomerization:
isomerization vs. insertion:
etc.
i
π j
=ri
rj
iso.1
π iso.2
=riso.1
riso.2
=k iso.1
kiso.2
≈ exp(ΔΔG1, 2
kT)
i
i∑ = 1
iso.1
π ins. 1, 2
=riso.1
rins.1, 2
≈kiso.1
k ins.1, 2 Kcompl. polefin
][ 01,1 isokr =
][ 02,2 isokr =
olefincomplins
insins
pKk
kr
][
][
0..
0..
===
][ 01,1 isokr =
- alkyl -agostic complexes;- olefin complex;
37
Simulations of polymer growth and isomerizationSimulations of polymer growth and isomerization
main chainprimary branch
secondary branch
tertiary branch
etc.
Results:- Polymer chain;- Total No. of branches;- Classification of branches: no. of branches of a given type, and their length;- Molecular weight;
Results:- Polymer chain;- Total No. of branches;- Classification of branches: no. of branches of a given type, and their length;- Molecular weight;
Propylene polymerization (theoretical data)Propylene polymerization (theoretical data)
R = H; Ar = H
CC
NN
Pd
A. Michalak, T. Ziegler, „Stochastic modelling of the propylene polymerization catalyzed by the Pd-based diimine catalyst: influence of the catalyst structure and the reaction conditions on the polymer microstructure”, J. Am. Chem. Soc, 2002, in press.
R=H; Ar= Ph
CC
CCCC
CNN CCC
CCC C
Pd
Propylene polymerization (theoretical data)Propylene polymerization (theoretical data)
R=An; Ar= Ph(i-Pr)2
CCC
CC
CC
C
C
CC
C
CC
C
CC
C
C
CC
C
N CNC CC
C
C
CCC C
CC
Pd
CC
Propylene polymerization (theoretical data)Propylene polymerization (theoretical data)
Propylene polymerization - effect of the catalystPropylene polymerization - effect of the catalyst
R=H; Ar=H: 331.6 br.; 66.7% 33.3%; 0
R=H; Ar=Ph: 122.5 br.; 51.7%; 40.1%; 14.2
R=H; Ar=Ph(CH3)2: 269.6 br.;60.9%; 38.1%; 0.89
R=H; Ar=Ph(i-Pr)2: 269.6 br.; 60.9%; 38.1%; 1.37
R=CH3; Ar=Ph(CH3)2: 251.0 br.; 59.7%; 38.7%; 0.93
R=CH3; Ar=Ph(i-Pr)2: 238.2 br.;61.7%; 36.5%; 2.6
R=An; Ar=Ph(i-Pr)2: 255.6 br.; 59.9%; 38.5%; 1.35
The values above the plots denote: the average number of branches / 1000 C, % of atoms in the main chain and % in primary branches, and the ratio between the isomerization and insertion steps. Colors are used to mark different types of branches (primary, secondary, etc.).
42
220
240
260
280
300
320
0 100 200 300 400 500
T [K]
No. of branches / 1000 C
Propylene polymerization - temperature effectPropylene polymerization - temperature effect
T=98K
T=198K
T=298K
T=398K
T=498K
43
C
CC
C
C
CC
C
CC
C
CC
C
C
N CNC CC
CC
C
C C
CC
Pd
CC
220
240
260
280
300
320
0 100 200 300 400 500
T [K]
No. of branches / 1000 C
Propylene polymerization - temperature effectPropylene polymerization - temperature effect
T=98K
T=198K
T=298K
T=398K
T=498K
44
C
CC
C
C
CC
C
CC
C
CC
C
C
N CNC CC
CC
C
C C
CC
Pd
CC
• Two insertion pathways: 1,2- i 2,1-
• Chain straightening follows 2,1-insertion only
•Lower barrier for the 1,2-insertion (by c.a. 0.6 kcal/mol)
• Practically each 2,1-insertion is followed by chain straighening
220
240
260
280
300
320
0.001 0.01 0.1 1
p [ arbitrary units]
No. of branches
Propylene polymerization - pressure effectPropylene polymerization - pressure effect45
C
CC
C
C
CC
C
CC
C
CC
C
C
N CNC CC
CC
C
C C
CC
Pd
CC
220
240
260
280
300
320
0.001 0.01 0.1 1
p [ arbitrary units]
No. of branches
Propylene polymerization - pressure effectPropylene polymerization - pressure effect46
C
CC
C
C
CC
C
CC
C
CC
C
C
N CNC CC
CC
C
C C
CC
Pd
CC
Exp.: 213br. / 1000 C
„Ideal” – no chain straighening333.3
Propylene polymerization - pressure effectPropylene polymerization - pressure effect
p=0.1
p=0.01
p=0.001
p=0.0001
47
C
CC
C
C
CC
C
CC
C
CC
C
C
N CNC CC
CC
C
C C
CC
Pd
CC
Ethylene polymerization by Pd-based diimine catalyst Simulations from experimental data (G)
Ethylene polymerization by Pd-based diimine catalyst Simulations from experimental data (G)
48
CCC
CC
CC
C
C
CC
C
CC
C
CC
C
C
CC
C
N CNC CC
C
C
CCC C
CC
Pd
CC
0
30
60
90
120
150
0.001 0.01 0.1 1
p [ arbitrary units]
No. of branches
Ethylene polymerization by Pd-based diimine catalyst Simulations from experimental data
Ethylene polymerization by Pd-based diimine catalyst Simulations from experimental data
49
CCC
CC
CC
C
C
CC
C
CC
C
CC
C
C
CC
C
N CNC CC
C
C
CCC C
CC
Pd
CC
0
30
60
90
120
150
0.001 0.01 0.1 1
p [ arbitrary units]
No. of branches
Ethylene polymerization by Pd-based diimine catalyst Simulations from experimental data
Ethylene polymerization by Pd-based diimine catalyst Simulations from experimental data
50
CCC
CC
CC
C
C
CC
C
CC
C
CC
C
C
CC
C
N CNC CC
C
C
CCC C
CC
Pd
CC
Exp.
Ethylene polymerization by Pd-based diimine catalyst Simulations from experimental data
Ethylene polymerization by Pd-based diimine catalyst Simulations from experimental data
51
p
Ethylene polymerization by Pd-based diimine catalyst Simulations from experimental data
Ethylene polymerization by Pd-based diimine catalyst Simulations from experimental data
52
p
0
30
60
90
120
150
180
0 100 200 300 400 500
T [K]
No. of branches
Ethylene polymerization by Pd-based diimine catalyst Simulations from experimental data
Ethylene polymerization by Pd-based diimine catalyst Simulations from experimental data
53
CCC
CC
CC
C
C
CC
C
CC
C
CC
C
C
CC
C
N CNC CC
C
C
CCC C
CC
Pd
CC
0
30
60
90
120
150
180
0 100 200 300 400 500
T [K]
No. of branches
Ethylene polymerization by Pd-based diimine catalyst Simulations from experimental data
Ethylene polymerization by Pd-based diimine catalyst Simulations from experimental data
54
CCC
CC
CC
C
C
CC
C
CC
C
CC
C
C
CC
C
N CNC CC
C
C
CCC C
CC
Pd
CC
Ethylene polymerization by Pd-based diimine catalyst Simulations from experimental data (G)
Ethylene polymerization by Pd-based diimine catalyst Simulations from experimental data (G)
55
CCC
CC
CC
C
C
CC
C
CC
C
CC
C
C
CC
C
N CNC CC
C
C
CCC C
CC
Pd
CC
A. Michalak, T. Ziegler, „DFT and stochastic studies on the factors controlling branching and microstructure of polyethylenes in the polymerization processes catalyzed by the late-transition metal complexes”, in preparation
Ethylene polymerization - model studies on the effects of catalyst (elementary reaction barriers), temperature, and pressure on the
microstructure of polymers
Ethylene polymerization - model studies on the effects of catalyst (elementary reaction barriers), temperature, and pressure on the
microstructure of polymers
56
Ethylene polymerization - pressure / catalyst effects
Ethylene polymerization - pressure / catalyst effects
0
50
100
150
200
250
300
350
0.0001 0.001 0.01 0.1 1
E2=1E2=2E2=3E2=4E2=5E2=6E2=7E2=8E2=9N
o. o
f b
ran
ches
/ 10
00 C
p [arbitrary units]
E1=1.0 kcal/mol
57
Ethylene polymerization - pressure / catalyst effects
Ethylene polymerization - pressure / catalyst effects
0
50
100
150
200
250
300
350
0.0001 0.001 0.01 0.1 1
E2=1E2=2E2=3E2=4E2=5E2=6E2=7E2=8E2=9N
o. o
f b
ran
ches
/ 10
00 C
p [arbitrary units]
E1=1.0 kcal/mol
58
pressure independent region
0
50
100
150
200
250
300
350
400
450
0.0001 0.001 0.01 0.1 1
E1=2.0 kcal/mol
0
50100
150200
250
300350
400450
500
0.0001 0.001 0.01 0.1 1
E1=3.0 kcal/mol
0
100
200
300
400
500
600
0.0001 0.001 0.01 0.1 1
E1=4.0 kcal/mol
0
100
200
300
400
500
600
0.0001 0.001 0.01 0.1 1
E1=6.0 kcal/mol
59
The faster is the isomerisation (compared to insertions), the more extended is the pressure independent region.
The faster is the isomerisation (compared to insertions), the more extended is the pressure independent region.For Ni-diimine catalyst the isomerisation is slower then for Pdi.e. for Pd the pressure independent region is more extended toward higher values of the pressure
For Ni-diimine catalyst the isomerisation is slower then for Pdi.e. for Pd the pressure independent region is more extended toward higher values of the pressure
The polyethylene galleryThe polyethylene gallery
E1E2=2 kcal/mol
E1E2=5 kcal/mol
E1E2=7 kcal/mol
E1E2=5 kcal/mol
E1E2=5 kcal/mol
p=0.0001; T=298 K
60
Ethylene polymerization with the Ethylene polymerization with the neutral anilinotropone Ni-based neutral anilinotropone Ni-based
catalystcatalyst
Ethylene polymerization with the Ethylene polymerization with the neutral anilinotropone Ni-based neutral anilinotropone Ni-based
catalystcatalyst
Experimental data:
Hiks, F.A., Brookhart M.
Organometallics 2001, 20, 3217.
Experimental data:
Hiks, F.A., Brookhart M.
Organometallics 2001, 20, 3217.
Ethylene polymerization with the Ethylene polymerization with the neutral anilinotropone Ni-based neutral anilinotropone Ni-based
catalystcatalyst
Ethylene polymerization with the Ethylene polymerization with the neutral anilinotropone Ni-based neutral anilinotropone Ni-based
catalystcatalyst
Experimental data:
Hiks, F.A., Brookhart M.
Organometallics 2001, 20, 3217.
Experimental data:
Hiks, F.A., Brookhart M.
Organometallics 2001, 20, 3217.
0
20
40
60
80
100
120
0 100 200 300 400 500 600 700
p [psig]
br./1000C
0
10
20
30
40
50
60
70
80
20 40 60 80 100 120
T [C]
br./1000C
0
5
10
-5
-10
-15
-20N-isomers
O-isomers
Alkyl
AlkylAlkyl
Alkyl
-
-
- -
ins. TS
ins. TS ins. TS
ins. TS
iso. TS
iso. TS
1.9
-12.9
-17.9
0.01.9
9.5
5.8
1.33.4
-17.5-17.1
5.7
1.7
Secondary alkyl Primary alkyl
Ni-anilinotropone catalyst – results for real catalyst
0
5
10
-5
-10
-15
-20N-isomers
O-isomers
Alkyl
AlkylAlkyl
Alkyl
-
-
- -
ins. TS
ins. TS ins. TS
ins. TS
iso. TS
iso. TS
1.9
-12.9
-17.9
0.01.9
9.5
5.8
1.33.4
-17.5-17.1
5.7
1.7
Secondary alkyl Primary alkyl
Ni-anilinotropone catalyst – stochastic simulations
020
4060
80
100120
140160
0 0.02 0.04 0.06 0.08 0.1
p [arb.u.]
br./1000C
14 - 600 psig
Ni-anilinotropone catalyst – stochastic simulations
0
20
40
60
80
100
120
140
160
0 0.0038 0.0076 0.0114 0.0152 0.019 0.0228
p [arb.u.]
br./1000C
14 50 100 200 400 600p [psig]
Ni-anilinotropone catalyst – stochastic simulations
Theoret.
Exp.
0102030405060708090
100
40 50 60 70 80 90 100
T [C]
br./1000C
p = 0.011 arb.u. / p = 400 psig
Theoret.
Exp.
Ni-anilinotropone catalyst – stochastic simulations
Acknowledgements. This work was supported by the National Sciences and Engineering Research Council of Canada (NSERC), Nova Chemical Research and Technology Corporation as well as donors of the Petroleum Research Fund, administered by the American Chemical Society (ACS-PRF No. 36543-AC3). A.M. acknowledges NATO Fellowship. Important parts of the calculations was performed using the UofC MACI cluster.
Acknowledgements. This work was supported by the National Sciences and Engineering Research Council of Canada (NSERC), Nova Chemical Research and Technology Corporation as well as donors of the Petroleum Research Fund, administered by the American Chemical Society (ACS-PRF No. 36543-AC3). A.M. acknowledges NATO Fellowship. Important parts of the calculations was performed using the UofC MACI cluster.
ConclusionsConclusions
DFT:• energetics of elementary reactions in a reasonable agreement with experimental data • understanding of the electronic and steric influence of the catalysts substituents
Stochastic modelling:• provides a link between the molecular modeling on the microscopic and macroscopic level •identifies the factors controlling of the polyolefin branching and their microstructure •demonstrates that a huge range of polyolefin materials with specific microstructures can be rationally designed by modification of the catalysts• can be also useful for interpretation of the experimental results
DFT:• energetics of elementary reactions in a reasonable agreement with experimental data • understanding of the electronic and steric influence of the catalysts substituents
Stochastic modelling:• provides a link between the molecular modeling on the microscopic and macroscopic level •identifies the factors controlling of the polyolefin branching and their microstructure •demonstrates that a huge range of polyolefin materials with specific microstructures can be rationally designed by modification of the catalysts• can be also useful for interpretation of the experimental results
DFT:• energetics of elementary reactions in excellent agreement with experimental data • understanding of the electronic and steric influence of the catalysts substituents
Stochastic modelling:• provides a link between the molecular modeling on the microscopic and macroscopic level • allows one to identify the factors controlling of the polyolefin branching and their microstructure as well as its dependence on the reaction conditions• demonstrates that a huge range of polyolefin materials with specific microstructures can be rationally designed by modification of the catalysts• can be also useful for interpretation of the experimental results.`
DFT:• energetics of elementary reactions in excellent agreement with experimental data • understanding of the electronic and steric influence of the catalysts substituents
Stochastic modelling:• provides a link between the molecular modeling on the microscopic and macroscopic level • allows one to identify the factors controlling of the polyolefin branching and their microstructure as well as its dependence on the reaction conditions• demonstrates that a huge range of polyolefin materials with specific microstructures can be rationally designed by modification of the catalysts• can be also useful for interpretation of the experimental results.`