Introduction to NMR Spectroscopy and Imaging Lecture 09 Applications of Solid State NMR (Spring Term, 2011) Department of Chemistry National Sun Yat-sen

Introduction to NMR Spectroscopy and Imaging

Lecture 09 Applications of Solid State NMR

(Spring Term, 2011)

Department of ChemistryNational Sun Yat-sen University

核磁共振光譜與影像導論

• Polymers

• Glasses

• Porous materials

• Liquid crystals

Applications of Solid State NMR

Schematic of a typical semicrystalline linear polymer

Stereochemical issue in substituted polymers

H H

linear polyethylene

isotactic polypropylene

syndiotactic polypropylene

atactic polypropylene

Signature of stereoregularity in the solid state spectrum

Static 2D exchange spectrum for polyethyleneoxide (PEO)

Experiment Simulation

3D static 13C exchange spectra of polyethyleneoxide polyvinylacetate

Applications

• Polymers

• Glasses


• Liquid crystals

Static whole-echo 207Pb NMR spectrain Pb-silicate glasses

mol %PbO6650.531

4000 0 -4000 ppm

Linewidth ~400 kHz @ 9.4 T—> signals of 6 experiments summed up

Sodium silicate glasses

BO

NBO

Na2Si2O5

Na2Si3O7

Na2Si4O9

600 0 -600 ppm

Static 17O NMR spectra

bridging (BO) andnon-bridging (NBO)oxygens

Structure of glasses (I)

OSi

OO

OSi

O

O O

SiOO

O

Si

Si

Si

O

Si O

O

O

O

OO

OO

O

Na

Na

Na

NaSi

BO

NBO

29Si NMR spectra for sodium silicate glasses

static MAS

Q4

Q3 + Q2

0 -100 -200 ppm -60 -80 -100

mole %Na2O

34

37

41 Q2

Q3

Structure of glasses (II)

Q4

Q2

Q1Q3

OSi

HOO

OSi

O

O O

SiOHHO

HO

Si

Si

Si

O

SiO

HO

HO

HO

OO

OO

O

1H-29Si CPMAS intensity as a function of contact time

Different sites in a Na2Si4O9 glass with 9.1 wt% H2O

Q2

Q3

Q4

0 20 40contact time (ms)

Efficiency for (1H 29Si)-CP

2

CPCP decouplingdecoupling

11HH

29Si

AcquisitionAcquisition

29Si MAS NMR spectra for a CaSi2O5 glass

x 8

glass

crystal

SiO4 SiO5 SiO6

-50 -100 -150 -200 ppm

quenched from a10 GPa pressure meltisotopically enriched

high pressure phasenormal isotopes

11B MAS NMR spectra for a sodium borate glass

30 15 0 ppm

data

fit

data

fit

RBO4

BO4

NR

NR

R

slow cooled

fast cooled

(with 5 mole% Na2O)

31P MAS NMR spectra for sodium phosphate glasses

mol % Na2O

56

53

40

30

15

5

100 0 -100 ppm

Q1 Q2

Q3

31P double-quantum NMR spectrum

Dou

ble-

quan

tum

dim

ensi

on (

ppm

)

0

-60

0 -30Single-quantum dimension

1-1

1-2

2-1

2-2

Q1 Q2

1H MAS NMR spectrum for a GeO2-doped silica glass

loaded with H2 and UV-irradiatedafter subtractionof intense back-ground signal

GeH

SiOH + GeOH

12 6 0 -6 ppm

Sample contains ~8 1019 H atoms/cm3

(corresponding to about 500 ppm of H2O)

9.4 T, 10 kHz spinning

17O 3QMAS NMR spectrum for a glass on the NaAlO2-SiO2 join with Si/Al = 0.7

MA

S d

imen

sion

(pp

m)

Isotropic dimension (ppm)

-50

0

50

100

0 -10 -20 -30 -40 -50

Al-O-Al

Si-O-Al

17O 3QMAS NMR spectrum for a borosilicate

Si-O-Si

Si-O-B

B-O-B

MA

S d

imen

sion

(pp

m)

Isotropic dimension (ppm)

-25 -50 -75 -100

-100

-50

0

50

100

11B-{27Al} CP-HETCOR NMR spectrum

BO4BO3

AlO6

AlO4

AlO5

40 20 0 -20 ppm

-80

0

80

Applications

• Polymers

• Glasses


• Liquid crystals

Porous materials

Sodalite Zeolite A

Porous materials

Faujasite Cancrinite

Porous materials

Zeolite ZK-5 Zeolite Rho

Zeolite framework projections

AlPO4-5along [001]

AlPO4-11along [100]

VPI-5along [001]

High-resolution 29Si MASNMR spectra of syntheticNa-X and Na-Y zeolites

-80 -90 -100 -110 -80 -90 -100 -110

(Si/Al) = 1.03

1.19

1.35

1.59

1.67

1.87

2.00

2.35

2.56

2.61

2.75

43

21 0

4

32

10

n =Si(nAl) lines

Possible ordering schemes for zeolite Y

Si/Al = 1.67

Si

Al

Intensity ratios:Si(4Al):Si(3Al):Si(2Al):Si(1Al):Si(0Al)

29Si MAS NMR spectrum of highly siliceous mordenite

-110 -112 -114 -116 -118 ppm

2

1

3

Intensities

Mordenite structure along [001]

T-site No. per unit cell Neighbouring sites Mean T-O-T bond angle

T1 16 T1, T1, T2, T3 150.4°T2 16 T1, T2, T2, T4 158.1°T3 8 T1, T1, T3, T4 153.9°T4 8 T2, T2, T3, T4 152.3°

Mordenite structure along [001]

T-site No. per unit cell Neighbouring sites Mean T-O-T bond angle

T1 16 T1, T1, T2, T3 150.4°T2 16 T1, T2, T2, T4 158.1°T3 8 T1, T1, T3, T4 153.9°T4 8 T2, T2, T3, T4 152.3°

T1/T3/T2+T4 : 3 cross peaksT1/T4/T2+T3 : 2 cross peaksT2/T3/T1+T4 : 2 cross peaksT2/T4/T1+T3 : 3 cross peaks

29Si MAS NMR spectrum of highly siliceous mordenite

J-scaled COSY spectrum

-110 -112 -114 -116 -118 ppm

T1

T3

T2 + T4

T1/T3/T2+T4 : 3 cross peaksT1/T4/T2+T3 : 2 cross peaksT2/T3/T1+T4 : 2 cross peaksT2/T4/T1+T3 : 3 cross peaks

29Si MAS NMR spectra of ultrastabilized and hydrothermally realuminated zeolites

3

21

0Si/Al = 2.56

4.96 4.26 7.98

2.44 2.70 2.09

-80 -90 -100 -110 -120 -90 -100 -110 -120 -90 -100 -110 ppm

Chemical reactions in zeolites

{C} + H2O CO + H2 (water gas reaction)1000 °C


{C} + H2O CO + H2 (water gas reaction)

……. + x O2 (n-x) CO + n H2 + x CO2 (water gas shift)

1000 °C




CO + 2 H2 CH3OH (conversion of synthesis gas)

1000 °C

catalyst





CH3OH CH3OH + CH3OCH3

1000 °C

catalyst

Zeolites

150 °C






…….. complex mixture of hydrocarbons

1000 °C

catalyst

Zeolites

150 °C

Zeolites

300 °C






…….. complex mixture of hydrocarbons

1000 °C

catalyst

Zeolites

150 °C

Zeolites

300 °C

13C MAS NMR spectrum of H-ZSM-5 with 50 torr of adsorbed MeOH heated to 300 °C for 35

mins

40 30 20 10 0 -10 ppm

0 -5 -10 -15


mins

40 30 20 10 0 -10 ppm

0 -5 -10 -15 C H

scalar coupling

1JCH = 125 Hz

a quintet with ratio 1:4:6:4:1 is expected for methane

Heteronuclear 2D J-resolved 13C MAS NMR spectrum

26 24 22 18 17 16 15 -11 -12 ppm

300

200

100

0 Hz

-100

-200

-300

13C NMR spin diffusion spectrum of products of methanol conversion over zeolite ZSM-5

25 20 15 10 ppm


mins

40 30 20 10 0 -10 ppm

0 -5 -10 -15

Methane

Ethane

Propane

Cyclopropane

n-Butane

Isobutane

(n-Pentane)

Isopentane

n-Hexane

n-Heptane

Methylated aromatic products

190 185 180 140 135 130 125 ppm

CO

CH3

CH3

CH3

CH3

CH3

CH3

CH3

CH3

CH3

H3C

CH3CH3

CH3

CH3

CH3

CH3

H3C CH3

CH3

CH3H3C

CH3

CH3

CH3

CH3

CH3

CH3

CH3

*

* * * *

129Xe NMR as a sensitive tool for materials

0 S Xe Xe Xe E M

0: referenceS: surface collisionsXe: Xe-Xe collisionsE: electric field effectM: paramagnetic species

129Xe as a sensitive probe for various zeolites

Xe

atom

s /g

1020

1021

60 80 100 120 140 ppm

omega

NaY

ZK4

K - L

ZSM-11

ZSM-5

Applications

• Polymers

• Glasses


• Liquid crystals

Graphitic nanowires

Hexa-peri-hexabenzocoronene (HBC)

HBC monolayer on HOPG

Phase transitions of alkyl substituted HBC

Temperature dependence of the one dimensional charge carrier mobility

Liquid crystalline (dichotic) behaviour ofalkyl substituted HBC‘s

R = C12H25

Hexadodecyl-hexa-peri-hexabenzocoronene (HBC-C12)

Charge carrier mobility in HHTT S

S

S

S

S

S

1H DQ MAS NMR spectra of HBC-C12

-deuterated fully protonated

CD2

CD2

CD2

D2C

D2C

D2C

HH H

H

H

H

HH

HH

H

H

HH

0.180 nm

0.196 nm

Proposed stacking model based on solid state NMR

HH H

H

H

H

HHH

H

H

H

„Graphitic“ stacking

HH H

H

H

H

HHH

H

H

H

Spinning side band simulation in the DQ time domain

For an isolated spin pair, using N cycles of the recoupling sequence for both the excitation and reconversion of DQCs, the DQ time domain signal is given by:

S(t1, t2 0) sin

3

2Dsin 2 cos Rt1 NR

sin3

2Dsin 2 cos N R

D 0hH

2

82r 3with

Ref.: Graf et al. J. Chem. Phys. 1997, 106, 885

and are Euler angles relating the PAF of the diploar coupling tensor to the rotor fixed reference frame

-> distance information in a rigid system, or indication of mobility:

f 1 3cos2

2

Homonuclear correlation between I = 1/2 spins

aromatic protons at 8.3 ppm(crystalline phase)

aromatic protons at 6.2 ppm (LC phase)

aliphatic protons at 1.2 ppm(crystalline phase)

fitted dipolar coupling constants

DQ spinning side band patterns

R = 35 kHz

R = 10 kHz

R = 35 kHz

Effect of additional phenyl spacers

R = -C12H25 or -C6H4-C12H25

R

R

R

R

R

R

Space filling model for HBC-PhC1

X-ray diffraction patterns of the mesophases

Documents

Introduction to NMR Spectroscopy and Imaging Lecture 09 Applications of Solid State NMR (Spring Term, 2011) Department of Chemistry National Sun Yat-sen