Multi-dimensional NMR of Polymers

Pittcon 2007

Peter L. Rinaldi

Department of Chemistry University of Akron

Akron, OH 44325-3601

PeterRinaldi@uakron.edu

http://www.uakron.edu/colleges/artsci/depts/chemistry/magnet/presentations.php

Acknowledgments• Senior• E. McCord• M. Buback

• Funding• NSF (DMR-0073346, DMR-0330816)• Kresge Foundation, Donors to Kresge Challenge Program at UAkron• Ohio Board of Regents, Research Challenge• University of Akron• Dupont, Dow Chemical, Nalorac, Varian

StudentsT. SaitoM. MonwarD. BanerjeeA. Al-HamriD. SavantA. Nuamthanom

StaffV. DudipalaS. StakleffT. WaglerJ. Massey

PostdocsS. SahooF. Wyzgoski

StudentsH. Latz

Outline

• Introduction

• HSQC/HMBC/HSQC-TOCSY

• Isotopic Labeling

• HC Double Resonance

3D NMR

• Quantitative nD

• Conclusions

t2t1

Preparation Evolution Mixing Detection

2D

Preparation Detection

1D

Preparation Evol Mix Evol Mix Detection

t1 t3

3D

t2

a

b

c

1D, 2D & 3D NMR Pulse Sequences

f2

a b

FT(t2)

t1bt1

t2

a

f2

f1

dFT(t1)

t1

a

b

f2c

Schematic of 2D-NMR Processing

C-centeredB-centered

CCCECCECE

BCC/CCBBCB(2)

ECB/BCE

BBB(3)EBB(2)

EBECBB(2)/BBC(2)

CBCEBC/CBE

EEEEEB

BEB(2)CEECEC

BEC/CEB

E-centered

E = ethylene C = carbon monoxide B = n-butylacrylateCa. 200 pentad sequences

Possible Triads of Poly(EBC)Poly(ethylene-co-butylacrylate-co-carbon monoxide)

Combined Applications of HSQC, HMBC &/or HSQC-TOCSY

C Z

M

H

R

H

R

H HH

MYZ

WXMYZ

WXM

W

H

WXMMYZ

WXMYZAdiabatic Pulse Versions of 2D Experiments:Kupce & Freeman, J. Magn. Reson., 127, 36 (1997). Crouch et al., Magn. Reson. Chem., 42, 301 (2004). Boyer et al., J. Magn. Reson., 165, 253 (2003).

X Y

1D NMR of PolyEBC

ppm205.5206.0206.5207.0207.5208.0208.5209.0209.5

Ketone Carbonyl

ppm172.5173.0173.5174.0174.5175.0175.5176.0176.5

Ester Carbonyl

#003

#003

#002

#002

#001

#001

ppm10152025303540455055606570

E4

terminal

E1

1B4+

#001 60/30/10

E/B/C#003 50/30/20

E2

αCH2CEC

αδ+

α’’

E3

δ+δ+

(CH2)x

αCH2CEE

βCH2CEE

CHBE

βδ+

β’’CH methyl CE

E/B/C

Wyzgoski et al., Macromolecules, 37, 846 (2004).

Poly(EBC) HSQC & HMBC

Monwar et al., Anal. Bioanal. Chem., 378, 1414 (2004).

C-centeredB-centered

CCCECC/CCE

ECEBCC/CCB

BCB(2)ECB/BCE

BBB(3)EBB(2)

EBECBB(2)/BBC(2)

CBCEBC/CBE

EEEEEB

BEB(2)CEECEC

BEC/CEB

E-centered

E = ethylene C = 13C-carbon monoxide B = n-butylacrylate60 C-centered pentad sequences

Possible Triads of Poly(EBC*)Poly(ethylene-co-butylacrylate-co-carbon monoxide*)

Selective 13C Labeling

WXMMYZ

WXMYZ

X Y

C Z

M

H

R

H

R

H HH

W

H

R’ O

W13

HMBC Spectrum PolyEBC*

Monwar et al., Anal. Bioanal. Chem., 378, 1414 (2004).Al-hamri et al., Macromol. Chem. Phys., 206, 1520 (2005).

t2t1

Preparation Evolution Mixing Detection

2D

Preparation Detection

1D

Preparation Evol Mix Evol Mix Detection

t1 t3

3D

t2

a

b

c

1D, 2D & 3D NMR Pulse Sequences

A B CC C C

H H HHcHAHB

t1 t2

COSYa

decprep t1 t2Δ ΔC

H

HMQC

b

decprep t1 t2Δ Δ t3C

H

HMQC- COSY

c

1D, 2D & 3D NMR Spectra

CA

CCCB

Biological 3D-NMR Pulse Sequences

H

N C

H

C N

H

C

H

C

O O

a H

N C

H

C N

H

C

H

C

O O

b

H

N C

H

C N

H

C

H

C

O O

c H

N C

H

C N

H

C

H

C

O O

d

H

N C

H

C N

H

C

H

C

O O

e

R1 R2

R1 R2

R1 R2

R1 R2

R1 R2

HNCO HNCA

HCACO

HCA(CO)N

15N-TOCSY-HMQC

Clore & Gronenborn, Progress NMR Spectoscopy, 23, 43 (1991).Griesinger et al., J. Magn. Resonance, 84, 14 (1989).

Biomolecular NMR Spectroscopy. J. Evans. Oxford University Press, New York, 1995.

C C N

H O H

αC C N

H O H

α

R1 R2

1D 13C NMR of Labeled Poly(EBC)

200 180 160 140 120 100 80 60 40 20 ppm

Unlabeled

O

13C

OBuO

13CH

OBuO13C

X A

A B C D E GF

gt1 gt2 gt3 gt4 gt5 gt7 gt8

t313Caliph

t1/2 t1/2

T T T-t1/2

GARP

T+t1/2

Gz gt6

∆ ττ

∆ ∆∆ ∆ ∆Waltz-16 Waltz-161H

Waltz-16

Grzsiek and Bax, J. Magn. Resonance, B102, 103 (1993). Xia et al., J. Magn. Resonance, 143, 407 (2000).Sahoo et al., Macromolecules, 36, 6695 (2003).

13CC=O

13C

H

X

C

(C)(D)

(D)

(B)(F)

(E)

(G)

t1

t3

t2

1JCH

1JCC

H2C

HCACX 3D Pulse Sequence

R1 C

X

R1

C

H

H

C

R

H

C

H

H

C

H

R

1 42 3

3D-NMR Planes Poly(EB*C)

2.5

1.5

2.5

1.5

46 45

a b

41 40

dc

HSQC

HMBC

δC ppm

δ H p

pm

176 174

a

b cd

ppm

F1=175.31 F1=174.8F1=174.14F1=174.56

HC

AC

X

a b cd

a b c d

F2 (ppm)

( (() ) )p q r

poly(ethylene-co-n-butylacrylate*-co-carbon monoxide)

Sahoo et al., Macromolecules, 36, 6695 (2003). Sahoo et al., J. Magn. Reson, 168, 352 (2004).

13C

H

O OBu

C(C)

(D)

(D)

(B)(F)

(E)

(H)

t1

t3

t2

1JCH

1JCC

H2C

A B C D E F H

gt1 gt2 gt3 gt4 gt5 gt7 gt8

t313C

t1/2 t1/2

T T T-t1/2

GARP∆ ∆ ∆ ∆

T+t1/2

Gz gt6

∆ ττ

∆ ∆∆ ∆ ∆1H

DIPSI-2

G

(G)

gt9

HCACX-HH-TOCSY 3D Pulse Sequence

Waltz-16 Waltz-16Waltz-16

R1 C

X

R1

C

H

H

C

R

H

C

H

H

C

H

R

1 42 3

Sahoo et al., J. Magn. Reson, 168, 352 (2004).

3D-NMR Planes Poly(EB*C)

2.5

1.5

2.5

1.5

46 45

a b

41 40

dc

HSQC

HMBC

δC ppm

δ H p

pm

176 174

a

b cd

ppm

47 44 47 44 42 39 42 39

F1=175.31 F1=174.8F1=174.14F1=174.56

HC

AC

X

a b cd

a b c d

HC

AC

X-H

H-T

OC

SYF2 (ppm)

( (() ) )p q r

poly(ethylene-co-n-butylacrylate*-co-carbon monoxide)

Sahoo et al., J. Magn. Reson, 168, 352 (2004).

Poly(EB*C) 3D Planes at δCO=175.3, 174.8

M. Monwar et al., Macromolecules, 2006, 39, 2886.A. Al-hamri et al. Macromolecules, 2006, 39, 5768.

Poly(EB*C) 3D Planes at δCO=174.56, 174.14

M. Monwar et al., Macromolecules, 2006, 39, 2886.A. Al-hamri et al. Macromolecules, 2006, 39, 5768.

CX CA

CC

C

H

H

H

H

H

HO

H

OCOCH3

XA

CX CA

CC

CH

HCO2BU

H

H

HH

HO

XA A

CX

CA

132 ppm

CC

C

H

H

H

H

H

HO

H

C OOC4H9X

A

CX CA

Ph

CH CH2

CH2

COCH

Ph

n

Ph

A

A

X

a

b

c

d

Other Polymer Structure Problems Amenable to 3D 1H{13C} Double Resonance Analysis

37 ppm

172 ppm

152 ppm

Ph

CH CH2

CH2

COCH

Ph

n

Ph

A

A

X

3.1

3.7

1.8

3.6

55.5 48.555.5 48.5

55.5 48.555.5 48.5

3.1

3.7

55.5 48.5

gHSQC

gHC

AC

XgH

CAC

X-H

H-T

OC

SY

1,3-diphenyl-2-propanone-1,2,3-13C3 initiated polystyrene

CH CH2

F2 (ppm)

F3(ppm)

F1 (ppm)

F2 (ppm)

3D-NMR DBK-Terminated Polystyrene

F. J. Wyzgoski et al., Polymer Preprints, 45(2), 583-584 (2004).

poly(ethylene-co-n-butylacrylate-co-carbon monoxide*)

32364044

32364044

32364044

32364044

gHMBC HC

AC

XH

CAC

X-H

H-T

OC

SY

3244

3244

3244

3244

1.0

2.0

3.0

1.0

2.0

3.0

2.0

3.0206209

F2 (ppm)

F3(ppm)F2

(ppm)

F1 (ppm)

3D Planes Poly(EBC*)

C

H

HCO2BU

H

H

HH

HO

A. Alhamri, et al, Macromolecules, 39, 5768-5776 (2006).

CC

C

H

H

H

H

H

HO

H

OCOCH3

poly(ethylene-co-vinylacetate*-co-carbon monoxide)

gHSQC

gHC

AC

XgH

CAC

X-H

H-T

OC

SY

2.0

4.0

40 30

30403040

30403040

F2 (ppm)

F3(ppm)

3D-NMR Poly(EV*C)

CX CA

XA

D. Savant et al., Polymer Preprints, 47(1), 33-34 (2006).

1012023030

13C NMR of (poly(ethylene-co-octene)

45 40 35 30 25 20 15 10 5 (ppm)

0 51 01 52 02 53 03 5

1H NMR of poly(ethylene-co-octene)

3.5 3.0 2.5 2.0 1.5 1.0 0.5 (ppm)

750 MHz 1D NMR PolyEO

Quantitative 2D NMR Complications

• Relaxation times – range• J Coupling range• Multiplicity (C, CH, CH2, CH3)• Resonance offset effects

Koskela,H.; Väänänen,T. Magn.Reson.Chem 2002,40,705Heikkinen S.; et al. J. Am. Chem. Soc., 2003, 125, 4362.Koskela,H; Kilpeläinen,I; Heikkinen,S. J.Magn.Reson 2005,174,237Zhang, L; Gellerstedt, G; Magn. Reson. Chem., 2007, 45, 37.

64% Octene

98% Octene

99% Octene

1D 13C NMR Spectra of Poly(EO)

1D 13C Expansion of αα Region

Quantitative 2D-NMR

• Compare x-peak intensities within group• Same J couplings• Same multiplicity• Similar relaxation confirmed by 1H

relaxation measurements• Small offset effects

13C

1H

decouple

at

d1 d2 d3 d3 d4 d4

180° 90° 180°

180° 90° 180° 90° 180°

D.P. Burum , R.R. Ernst, J. Magn. Resonance, 39(1), 163-168 (1980). Brown. et al., J. Magn. Resonance, Series A, 110(1), 38-44 (1994).

2D-HSQC detected 1H relaxation timesHeikkinen et al., J. Am. Chem. Soc., 125, 4362 (2003).

Zhang & Gellerstedt, Magn. Reson. Chem., 45, 37 (2007).

13C Detected 1H T1’s

αα 1H T1’s ca. 200 ms

In m-centered structures, the environments for geminal methylene protons are different and have different chemical shifts

In r-centered structures, both methylene protons have similar environments and have similar chemical shifts.

= R group

αα -CH2 Chemical Shift Patterns

Copolymer A Copolymer B Copolymer C

Expansions of gHMBC & gHSQC αα for of copolymer A,B and C

F1 (ppm)40.040.240.440.640.841.041.241.441.641.842.042.2

F2(ppm)1.15

1.20

1.25

1.30

1.35

1.40

1.45

321

gHSQC

1D & 2D Quantitative Data for Copolymer A

1JCH = 125 HzRD = 1 sec

Copolymer A Copolymer B

Quantitative analysis of copolymers A and B by 1D 13C and 2D gHSQC NMR

1D & 2D Quantitative Data for Copolymer A & B

Maybe There is Hope After All Copolymer C

Conclusions

• Biological nD NMR methods adaptable to synthetic molecules

• Can be enormously useful for simplifying and solving structure problems

• Equally useful for solving problems with mixtures of small molecules

Other Useful References• Newmark, R. A. Two Dimensional NMR of Polymers, Polymer

News, 28, 40 (2003).

• Rinaldi, P.L. Polymer Characterization by Three Dimensional NMR, in NMR Spectroscopy of Polymers in Solution and in the Solid State, ACS Symposium Series, Eds. H. N. Cheng & A. D. English, 834, 94 (2003).

• Rinaldi, P. L. Analyst, 129, 687 (2004).

• Sahoo, S. K. and Rinaldi, P. L. NMR of Polymers in Solution, Encyclopedia of Chemical Processing, ed. K. B. Lee, Dekker (2005), p 1907.

http://www.uakron.edu/colleges/artsci/depts/chemistry/magnet/presentations.php