1 Structural characterization of inorganic aluminosilicate systems: role of water (4) (4) +1 +3 +2 0 -1 -2 -3 t1 τ 90°-sel. +1 +3 +2 0 -1 -2 -3 t1 τ 90°-sel. Introduction – ss-NMR of inorganic systems NMR crystallography Problem of quadrupolar nuclei Removing of quadrupolar broadening (DOR, MQ/MAS) Enhancement of spectral resolution Structure of aluminosilicate systems Amorphous aluminosilicate inorganic polymers (AIP) – synthesis Primary structural data about Al/Si materials – 29 Si a 27 Al MAS NMR Amorphous-crystalline phase transition of AIPs How to get structural parameters 29 Si, 27 Al, 23 Na MAS NMR 27 Al MQ/MAS NMR 1 H MAS NMR and spin relaxation 29 Si CP/MAS a REDOR NMR (localization of H2O) VA-CT 29 Si CP/MAS (hydration extent) 1 H- 1 H MAS (interaction network) 27 Al REDOR MQ/MAS NMR Structural model Outlook Is NMR spectroscopy really such unique method? Magnetic Resonance Imaging Concept of NMR crystallography NMR crystallography ss-NMR Spectroscopy Molecular Modeling X-ray (Powder) Diffraction structural fragments process of structure refinement 1 H- 1 H spin-exchange 1 H- 13 C contacts 1 H- 15 N distances motional frequencies motional amplitudes chemical shifts etc. diffraction pattern pair distribution function analysis etc. conformation (DFT) prediction of long-range arrangement NMR parameters (CASTEP) etc. Refined structure with incorporated segmental dynamics, intermolecular interaction and supramolecular architecture Applications Finding relations between molecular structure, and physicochemical properties (bioavailability) of… … pharmaceuticals based on solid solution and solid dispersions of API in polymer matrix, NMR active nuclei – problem of inorganic systems; I>1/2 22 spins I=1/2 77 spins I=3/2, 5/2,9/2 1 spin I=1 Spin 1/2 Spin 3/2 m=1/2 m=-1/2 m=-1/2 m=1/2 m=3/2 m=-3/2 Spectrum: narrow signal 0,1-100 Hz Spectrum: broad signal 1000-100000 Hz ( 29 ( 29 ( 29 ( 29 3 cos 30 cos 35 8 1 cos 1 cos 3 2 1 cos 2 4 4 2 2 + - = - = θ θ θ θ θ P P =0 =-7/18 θ = 54.74° MAS narrows 2 nd order broadening only by a factor 3 to 4 Quadrupolar broadening =0 =-7/18 θ = 54.74° =0 =-7/18 θ = 54.74°
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Introduction –ss-NMR of inorganic systems NMR ... · NMR crystallography ss-NMR Spectroscopy Molecular Modeling X-ray (Powder) Diffraction structural fragments process of structure
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1
Structural characterization of inorganic aluminosilicate systems:
role of water
(4)(4)
+1
+3+2
0−1−2−3
t1 τ90°-sel.
+1
+3+2
0−1−2−3
t1 τ90°-sel.
Introduction – ss-NMR of inorganic systemsNMR crystallographyProblem of quadrupolar nucleiRemoving of quadrupolar broadening (DOR, MQ/MAS)Enhancement of spectral resolution
Structure of aluminosilicate systemsAmorphous aluminosilicate inorganic polymers (AIP) – synthesisPrimary structural data about Al/Si materials – 29Si a 27Al MAS NMRAmorphous-crystalline phase transition of AIPsHow to get structural parameters
29Si, 27Al, 23Na MAS NMR 27Al MQ/MAS NMR 1H MAS NMR and spin relaxation29Si CP/MAS a REDOR NMR (localization of H2O)VA-CT 29Si CP/MAS (hydration extent)1H-1H MAS (interaction network)27Al REDOR MQ/MAS NMRStructural model
Outlook
Is NMR spectroscopy really such unique method?
Magnetic Resonance Imaging
Concept of NMR crystallography
NMR crystallography
ss-NMR Spectroscopy
Molecular Modeling
X-ray (Powder) Diffraction
structural fragments
process of structure refinement1H-1H spin-exchange1H-13C contacts1H-15N distances
motional frequencies
motional amplitudes
chemical shifts
etc.
diffraction pattern
pair distribution function analysis
etc.
conformation (DFT)
prediction of long-range arrangement
NMR parameters (CASTEP)
etc.
Refined structure with incorporated segmental dynamics, intermolecular
interaction and supramoleculararchitecture
Applications
Finding relations between molecular structure, and physicochemical properties (bioavailability) of…
… pharmaceuticals based on solid solution and solid dispersions of API in polymer matrix,
NMR active nuclei – problem of inorganic systems; I>1/2
22 spins I=1/277 spins I=3/2, 5/2,9/2
1 spin I=1
Spin 1/2 Spin 3/2
m=1/2
m=-1/2
m=-1/2
m=1/2
m=3/2
m=-3/2
Spectrum: narrow signal 0,1-100 Hz
Spectrum: broad signal 1000-100000 Hz
( ) ( )
( ) ( )3cos30cos358
1cos
1cos32
1cos
244
22
+−=
−=
θθθ
θθ
P
P
= 0
=−7/18
θ = 54.74°MAS narrows 2nd order broadening
only by a factor 3 to 4
Quadrupolar broadening
= 0
=−7/18
θ = 54.74°
= 0
=−7/18
θ = 54.74°
2
( ) ( )
( ) ( )3cos30cos358
1cos
1cos32
1cos
244
22
+−=
−=
θθθ
θθ
P
P
= 0
=−7/18
θ = 54.74°
Quadrupolar broadening and MAS (off-MAS)
17O DAS crystobalit
DAS: Dynamic Angle Spinning
( ) ( )
( ) ( )3cos30cos358
1cos
1cos32
1cos
244
22
+−=
−=
θθθ
θθ
P
P
23Na DOR of sodium oxalate
DOR: Double Rotation
+1
+3+2
0−−−−1−−−−2−−−−3
evolution mixing
MQSQ ST SQ CT
z-filter“whole echo”
t1 ττττ
90°-sel.
CT
+1
+3+2
0−−−−1−−−−2−−−−3
evolution mixing
MQSQ ST SQ CT
z-filter“whole echo”
t1 ττττ
90°-sel.
CT
ppm
-200 ppm15
10
5
0
ppm
20 0 ppm15
10
5
0
23Na MQ/MAS Na2HPO4.H2O
Multiple-quantum NMR spectroscopy
ppm
-40-30-20-1020 10 0 ppm
-25
-20
-15
-10
-5
35
30
25
20
15
10
5
0
SQ
TQ
A1, A4
A3
A2
xx
Kyanite, z-filtered experiment at 11.7 T
anisotropic traces
traces for A1 and A4 cannot be resolved
27 kHz MAS frequency
250 kHz RF
excitation pulse: 1.9 µs
conversion pulse: 0.7 µs
90° selective pulse: 11 µs
Al-27 3Q MAS traces of Kyanite at different fields
50 40 30 20 ppm 20 10 ppm40 30 20 10 ppm
9.4 T 11.7 T 18.8 T
1.0 1.0 1.0 0.8 1.0 0.8 0.7 1.02.0Int:
27Al 3Q MAS of Kyanite at different fields
Multiple-quantum NMR spectroscopy
ppm
-2020 0 ppm15
10
5
0
23Na MQ/MAS
Form III
-20-100 ppm
-2040 20 0 ppm
23Na MAS NMR
31P MAS NMR
MQ/MAS NMR spectroscopy – polymorphism of ATP
3
-50 -100 ppm
80 60 40 20 ppm
27Al
29Si
Fly ash-slag-metakaoiline
80 60 40 20 ppm
-50 -100 ppm
27Al
29Si
CSH gel
80 60 40 20 ppm
-50 -100 ppm
Typical aluminosilicateinrognic polymer (AIP)
27Al
29Si
ppm
ppm -50 -100 ppm
80 60 40 20 ppm
Zeolite system
27Al
29Si
27Al
29Si
80 60 40 20 ppm
-50 -100 ppm
Slightly crystalline AIP system
Variability of Al/Si materials Synthesis of AIP systems
Kaolin650°C Metakaolin
Al4(OH)8Si4O10
1. Calcination
activation @ RT
Primary units2.Activation
Si2O5.Al2O2
MetakaolinSi2O5.Al2O2 + 5H2O+2NaOH
Si
OH
OHOH
OH
Si
OH
OHOH
OHAl
-
OH
OHOH
OH Na+
Al-
OH
OHOH
OH Na+
polycondensation @ RT
Primary building units
3. Polycondensation
Si
OH
OHOH
OH
Si
OH
OHOH
OHAl
-
OH
OHOH
OH Na+
Al-
OH
OHOH
OH Na+ Si
OH
OO
OH
Al-
OH
OOH
Si
OHO
OH
Al-
OHOH
Na+
Na+
OH2
OH2
OH2
OH2
-4H2O
Amorphous network
Geopolymers and NMR, Davidovits: Geopolymers (1994)
29Si MAS NMR
Structure of AIP systems
Q4(4Al)
Q4(3Al) Q4(2Al)
Q4(1Al)
Q4(0Al)
SiO4 AlO4
Q4(4Al)
Q4(0Al)
Q4(3Al)
Q4(1Al)
a)
b)
100 50 0 ppm
Al (IV)
Al (V) Al (VI)
Simple calcination:formation of metakaoline
7days @ RT&
1day @ 140°C; HT
27Al MAS NMR
Al (V) ssb
-100-50 ppm
1day @ RT
7days @ RT
177day @ RT
7days @ RT&
1day @ 100°C; HT
Q4(0Al)
Q4(1Al)
Q4(2Al)
Q4(4Al)
Q4(3Al)
Q0/Q1
(OH)
29Si MAS NMR
Calcination with NaOH: formation of geopolymer precursor
Hyd
roth
erm
al tr
eatm
ent
Norm
al cu
ring
Calc
ination
Hyd
roth
erm
al tr
eatm
ent
Norm
al cu
ring
Calc
ination
Si-O-
D. Koloušek, J. Brus et al. JOURNAL OF MATERIALS SCIENCE 42 (22): 9267-9275 NOV 2007.
Synthesis of AIP systems
Method A Method B
NT/7 d HT/7 dHT/14 d
HT/21 dHT/28 d
0
10
20
30
40
50
60
70
Str
engh
t, M
Pa
Experimental conditions
Stable
system
Unstable
system
Time dependence of compression strength
(artificial aging)
Stable
system
Unstable
system
Structural instability of AIPs: spontaneous crystallization
Stable system
Unstable system
Basis structural parameters: 29Si,27Al,23Na MAS NMR
Untreated AIPsStable system
Unstable system
4
Basis structural parameters: 29Si,27Al,23Na MAS NMR
Artificially aged AIPsStable system
Unstable system
Basis structural parameters: 27Al MQ/MAS NMR
AIPs before and after accelerated agingStable system
Unstable system
Basis structural parameters : 1H MAS NMR, relaxation