- Quantitative NMR
This material is based upon work supported by the National Science Foundation under grants No. 0138117 and EEC-0813570.
-
DP/MAS with Hahn echo at 2 tr
- Difficulty
-
!
- Description
- Quantitative 13C spectra (after long recycle delay), without baseline distortion.
- Requires
- high spinning frequency (e.g. 14 kHz)
- References
-
-
Jingdong Mao
and
Klaus Schmidt-Rohr
"Accurate Quantification of Aromaticity and Nonprotonated Aromatic Carbon Fraction in Natural Organic Matter by
13C Solid State Nuclear Magnetic Resonance"
Environ. Sci. Technol.
38: 2680-2684
(2004).
-
Jingdong Mao
,
Wei-Guo Hu
,
Klaus Schmidt-Rohr
,
G. Davies
,
E. A. Ghabbour
and
B. Xing
"Quantitative Characterization of Humic Acids by Solid-State
13C NMR"
Soil Sci. Soc. of Am. J.
64: 873-884
(2000).
-
MultiCP (with Hahn echo at 2 tr)
- Difficulty
-
!
!
- Description
- Essentially quantitative cross-polarization 13C spectra, without baseline distortion.
- Requires
- Usually high spinning frequency (e.g. 14 kHz)
- References
-
-
Robert L. Johnson
and
Klaus Schmidt-Rohr
"Quantitative Solid-State
13C NMR Spectra with Signal Enhancement by Multiple Cross-Polarization"
J. Magn. Reson.
239: 44-49
(2014).
-
ComPmultiCP (with Hahn echo at 2 tr)
- Difficulty
-
!
!
- Description
- MultiCP with composite flip-store pulse, providing better tolerance to flip-angle error and/or B1 inhomogeneity, and wider Hartmann-Hahn matching condition.
- Requires
- Usually high spinning frequency (e.g. 14 kHz)
- References
-
-
Pu Duan
and
Klaus Schmidt-Rohr
#
"Composite-pulse and partially dipolar dephased multiCP for improved quantitative solid-state
13C solid-state NMR"
J. Magn. Reson.
285: 68 - 78
(2017).
-
DP/MAS with dipolar dephasing (recoupled)
- Difficulty
-
!
- Description
- 13C spectra of nonprotonated C, nearly quantitative
- Requires
- High spinning frequency (e.g. 14 kHz)
- Notes
- Spectral editing, but essentially quantitative (90% efficient for most nonprotonated C)
- References
-
-
Jingdong Mao
and
Klaus Schmidt-Rohr
"Accurate Quantification of Aromaticity and Nonprotonated Aromatic Carbon Fraction in Natural Organic Matter by
13C Solid State Nuclear Magnetic Resonance"
Environ. Sci. Technol.
38: 2680-2684
(2004).
- 2D HETCOR FOR SITE IDENTIFICATION
The FSLG as programmed in the following HETCOR experiments probably works only in the specified XWINNMR version. You may need to replace it with your own version of FSLG.
-
¹H-¹³C HETCOR
- Difficulty
-
!
!
!
- Description
- 1H-13C HETCOR with FSLG decoupling and LGCP transfer
- Requires
- higher power for good 1H resolution; 6 – 12 kHz MAS
- Notes
- HETCOR has been used and improved by various groups, after the pioneering work of Caravatti et al.Chem. Phys. Lett., 100, 305 (1983). Also compare HETCOR with fast MAS at high field.
-
HETCOR after ¹H CSA filter
- Difficulty
-
!
!
!
!
!
- Description
- Suppresses NH/OH signals in HETCOR spectra (overlap with aromatic H)
- References
-
-
Klaus Schmidt-Rohr
and
Jingdong Mao
"Selective Dephasing of OH and NH Proton Magnetization Based on
1H Chemical-Shift Anisotropy Recoupling"
J. Magn. Reson.
157: 210-217
(2002).
- SPECTRAL EDITING etc.
This material is based upon work supported by the National Science Foundation under grant No. 0138117. Any opinions, findings, and conclusions or recommendations expressed in this material are those of author(s) and do not necessarily reflect the views of the National Science Foundation.
-
Dipolar DEPT for CH-only spectra
- Difficulty
-
!
!
!
!
- Description
- Selects CH (methyne) signals
- Requires
- Higher power during 2.16 tr = 540 us; 4kHz MAS
- References
-
-
Jingdong Mao
,
L. S. Hundal
,
M. L. Thompson
and
Klaus Schmidt-Rohr
"Nuclear Magnetic Resonance and Diffuse-Reflectance Infrared Fourier-Transform Spectroscopy of Sludge-Derived Biocolloidal Organic Matter"
Environ. Sci. Technol.
37: 1751-1757
(2003).
-
Klaus Schmidt-Rohr
and
Jingdong Mao
"Efficient CH-Group Selection and Identification in
13C Solid-State NMR by Dipolar DEPT and
1H Chemical-Shift Filtering"
J. Am. Chem. Soc.
124: 13938-13948
(2002).
-
CP/T₁/TOSS
- Difficulty
-
!
- Description
- Use to determine recycle delay for DP/MAS
- Requires
- high sensitivity and therefore moderate spinning frequency (6.5 kHz)
- References
-
-
Jingdong Mao
and
Klaus Schmidt-Rohr
"Accurate Quantification of Aromaticity and Nonprotonated Aromatic Carbon Fraction in Natural Organic Matter by
13C Solid State Nuclear Magnetic Resonance"
Environ. Sci. Technol.
38: 2680-2684
(2004).
-
Jingdong Mao
,
Wei-Guo Hu
,
Klaus Schmidt-Rohr
,
G. Davies
,
E. A. Ghabbour
and
B. Xing
"Quantitative Characterization of Humic Acids by Solid-State
13C NMR"
Soil Sci. Soc. of Am. J.
64: 873-884
(2000).
-
SPIDER (Saturation-Pulse-Induced Dipolar Exchange with Recoupling)
- Difficulty
-
!
!
!
!
- Description
- Selects C bonded to N
- Requires
- 1H-14N-13C triple-resonance equipment, 5 kHz MAS
- References
-
-
Klaus Schmidt-Rohr
,
Jingdong Mao
and
D. C. Olk
"Nitrogen-Bonded Aromatics in Soil Organic Matter and Their Implications for a Yield Decline in Intensive Rice Cropping"
Proc. Natl. Acad. Sci. USA
101: 6351-6354
(2004).
-
Klaus Schmidt-Rohr
and
Jingdong Mao
"Selective Observation of Nitrogen-Bonded Carbons in Solid State NMR by Saturation-Pulse Induced Dipolar Exchange with Recoupling"
Chem. Phys. Lett.
359: 403-411
(2002).
-
CSA filter: 5-pulse version(2)
- Difficulty
-
!
- Description
- Selects alkyl (i.e. sp3-hybridized) C, e.g. O-C-O (which overlap with aromatic C) by five-pulse CSA dephasing
- Requires
- ca. 5 kHz MAS; short CP for O-CH-O selection; long CP & gated decoupling for O-Cq-O selection
- Notes
- compare SUPER sequence (5.3) for measurement of all three CSA principal values
- References
-
-
Jingdong Mao
and
Klaus Schmidt-Rohr
"Separation of Aromatic-Carbon
13C NMR Signals from Di-Oxygenated Alkyl Bands by a Chemical-Shift-Anisotropy Filter"
Solid State NMR
26: 36-45
(2004).
-
CH₂ spectral editing by selection of three-spin coherence
- Difficulty
-
!
!
!
!
- Description
- Selects CH2 (methylene) signals
- Requires
- Higher power during tr = 140 us; 5.8 kHz MAS
- Notes
- ca. 6% efficiency
-
CSA filter: 5-pulse version
- Difficulty
-
!
- Description
- Selects alkyl (i.e. sp3-hybridized) C, e.g. O-C-O (which overlap with aromatic C) by five-pulse CSA dephasing
- Requires
- ca. 5 kHz MAS; short CP for O-CH-O selection; long CP & gated decoupling for O-Cq-O selection
- Notes
- compare SUPER sequence (5.3) for measurement of all three CSA principal values
- References
-
-
Jingdong Mao
and
Klaus Schmidt-Rohr
"Separation of Aromatic-Carbon
13C NMR Signals from Di-Oxygenated Alkyl Bands by a Chemical-Shift-Anisotropy Filter"
Solid State NMR
26: 36-45
(2004).
-
CSA filter: 3-pulse version
- Difficulty
-
!
- Description
- Selects alkyl (i.e. sp3-hybridized) C, e.g. O-C-O (which overlap with aromatic C) by three- pulse CSA dephasing
- Requires
- ca. 5 kHz MAS; short CP for O-CH-O selection; long CP & gated decoupling for O-Cq-O selection
- Notes
- compare SUPER sequence (5.3) for measurement of all three CSA principal values
- References
-
-
Jingdong Mao
and
Klaus Schmidt-Rohr
"Separation of Aromatic-Carbon
13C NMR Signals from Di-Oxygenated Alkyl Bands by a Chemical-Shift-Anisotropy Filter"
Solid State NMR
26: 36-45
(2004).
-
Recoupled long-range dipolar dephasing reference sequence
- Difficulty
-
!
- Description
- Selects nonprotonated aromatic carbons far from protons (e.g. charcoal)
- Requires
- DP/TOSS or CP/TOSS at ca. 7 kHz MAS
- References
-
-
Jingdong Mao
and
Klaus Schmidt-Rohr
"Recoupled Long-Range C-H Dipolar Dephasing in Solid-State NMR, and Its Use for Spectral Selection of Fused Aromatic Rings"
J. Magn. Reson.
162: 217-227
(2003).
-
RIDER (Relaxation-Induced Dipolar Exchange with Recoupling)
- Difficulty
-
!
!
- Description
- Selects C bonded to N (and slowly rotating segments)
- Requires
- Same pulse sequence as CODEX; in contrast to SPIDER, only 1H-13C double-res. equipment is needed; but slow dynamics will produce artifacts.
- References
-
-
Kay Saalwaechter
and
Klaus Schmidt-Rohr
"Relaxation-Induced Dipolar Exchange with Recoupling: A MAS NMR Method for Determining Heteronuclear Distances without Irradiating the Second Spin"
J. Magn. Reson.
145: 161-172
(2000).
- ¹H SPIN DIFFUSION with ¹³C detection (HETCOR, CHHC)
-
HETCOR after on-resonance ¹H chemical-shift filter
- Difficulty
-
!
!
!
- Description
- Suppression of dominant signals in HETCOR to reveal small bands
- Notes
- KSR & Mao, unpublished
-
CHHC with MAD (Multiple Alternating Depolarization)
- Difficulty
-
!
!
- Description
- 2D 13C-13C NMR with cross peaks due to 1H spin diffusion
- Notes
- long measuring times at long mixing times (2% effic.)
- References
-
-
S-S. Hou
,
Qiang Chen
and
Klaus Schmidt-Rohr
"Two-Dimensional
13C NMR with
1H Spin Diffusion for Characterizing Domain Sizes in Unlabeled Polymers"
Macromolecules
37: 1999-2001
(2004).
- ¹H NMR
-
¹H CRAMPS after ¹H CSA filter
- Difficulty
-
!
!
!
!
- Description
- Suppression of NH/OH signals in 1H CRAMPS spectra
- Requires
- relatively slow MAS
- References
-
-
Klaus Schmidt-Rohr
and
Jingdong Mao
"Selective Dephasing of OH and NH Proton Magnetization Based on
1H Chemical-Shift Anisotropy Recoupling"
J. Magn. Reson.
157: 210-217
(2002).
-
¹H background suppression
- Difficulty
-
!
- Description
- Probehead background suppression in 1H one-pulse spectra
- Requires
- static or MAS spectra
- References
-
-
Qiang Chen
,
S-S. Hou
and
Klaus Schmidt-Rohr
"A Simple Scheme for Probehead Background Suppression in One-Pulse
1H NMR"
Solid State NMR
26: 11-15
(2004).
-
PRIDE (PRoton Inverse-detected DEuteron) NMR by HMQC and pulsed ¹H spin-lock
- Description
- Sensitivity-enhanced deuteron NMR of partially deuterated systems by 1H detection
- Requires
- static 2D experiment
- References
-
-
Klaus Schmidt-Rohr
,
K. Saalwü
,
chter. chter
,
S. -F. Liu
and
Mei Hong
"High-Sensitivity
2H-NMR in Solids by
1H Detection"
J. Am. Chem. Soc.
123: 7168-7169
(2001).
- DYNAMICS
-
CODEX (Centerband-Only Detection of Exchange)
- Difficulty
-
!
!
- Description
- Detection of slow (1-ms to 10-s) exchange dynamics under MAS of any spinning frequency
- Requires
- rotation-synchronized mixing time (MAS trigger)
- References
-
-
D. Reichert
,
T. J. Bonagamba
and
Klaus Schmidt-Rohr
"Slow-Down of
13C Spin Diffusion in Organic Solids by Fast MAS: A CODEX NMR Study"
J. Magn. Reson.
151: 129-135
(2001).
-
E. R. deAzevedo
,
Wei-Guo Hu
,
T. J. Bonagamba
and
Klaus Schmidt-Rohr
"Principles of Centerband-Only Detection of Exchange, and Extension to Four-Time CODEX"
J. Chem. Phys.
112: 8988-9001
(2000).
-
E. R. deAzevedo
,
Wei-Guo Hu
,
T. J. Bonagamba
and
Klaus Schmidt-Rohr
"Centerband-Only Detection of Exchange: Efficient Analysis of Dynamics in Solids by NMR"
J. Am. Chem. Soc.
121: 8411-8412
(1999).
-
SUPER (Separation of Undistorted Powderpatterns by Effortless Recoupling)
- Difficulty
-
!
!
!
- Description
- Separation of regular chemical-shift anisotropy powder patterns of dilute spins (13C, 29Si) with 0.155 scaling factor
- Requires
- 2.5 – 4 kHz MAS, 13C w1 = 12.12 wr, 1H w1 = 30 wr.
- References
-
-
S. -F. Liu
,
Jingdong Mao
and
Klaus Schmidt-Rohr
"A Robust Technique for Two-Dimensional Separation of Undistorted Chemical-Shift Powder Patterns in Magic-Angle Spinning NMR"
J. Magn. Reson.
155: 15-28
(2002).
-
WISE (2D ¹H WIdeline SEparation by ¹³C chemical shifts) with LGCP
- Difficulty
-
!
!
- Description
- Detect fast rotational dynamics by 1H line narrowing with 13C site resolution
- References
-
-
Klaus Schmidt-Rohr
and
Jingdong Mao
"Efficient CH-Group Selection and Identification in
13C Solid-State NMR by Dipolar DEPT and
1H Chemical-Shift Filtering"
J. Am. Chem. Soc.
124: 13938-13948
(2002).
- Fluoropolymers
This work has been authored at Iowa State University of Science and Technology under Contract No. W-7405-ENG-82 with U.S. Department of Energy. Any opinions, findings, and conclusions or recommendations expressed in this material are those of author(s) and do not necessarily reflect the views of the National Science Foundation.
-
2D ¹⁹F exchange NMR with fast MAS (>25 kHz)
- Difficulty
-
!
!
- Description
- Determine proximity of various 19F sites
- References
-
-
Qiang Chen
and
Klaus Schmidt-Rohr
"
19F and
13C NMR Signal Assignment and Analysis in a Perfluorinated Ionomer (Nafion) by Two-dimensional Solid-State NMR"
Macromolecules
37: 5995-6003
(2004).
-
¹³C CP NMR with fast MAS (>25 kHz) and pulsed ¹⁹F decoupling
- Difficulty
-
!
!
!
!
- Description
- High-resolution 13C spectra of fluoropolymers
- Requires
- fast spinning (>14 kHz); demanding set-up due to narrow CP condition and small signal of small sample.
- References
-
-
S. -F. Liu
and
Klaus Schmidt-Rohr
"High-Resolution Solid-State
13C NMR of Fluoropolymers"
Macromolecules
34: 8416-8418
(2001).
-
¹⁹F-¹³C HETCOR
- Difficulty
-
!
!
!
!
- Description
- One-bond correlations of 19F and 13C peak positions in fluoropolymers
- Requires
- little difficulty after 13C CP NMR with fast MAS (>25 kHz) and pulsed 19F decoupling
- References
-
-
Qiang Chen
and
Klaus Schmidt-Rohr
"
19F and
13C NMR Signal Assignment and Analysis in a Perfluorinated Ionomer (Nafion) by Two-dimensional Solid-State NMR"
Macromolecules
37: 5995-6003
(2004).