Klaus Schmidt-Rohr
Degrees
Johannes Gutenberg University Mainz, Ph.D.Johannes Gutenberg University Mainz, Diploma
Expertise
Solid-state NMR and structure determination of complex organic materials; NMR technique development; basic thermodynamics and chemical energy, including bioenergeticsProfile
Please visit my new faculty profile page here.We study the composition, nanoscale structure, and segmental motions of complex organic materials, in particular polymers, carbon materials, metal–organic frameworks, nanocomposites, and natural organic matter, using a variety of quantitative, selective, or two-dimensional nuclear magnetic resonance (NMR) experiments, many of which have been developed by us. We have also introduced new methods for quantitative analysis of scattering data of nanostructured materials. This dual approach has enabled us to “solve” important aspects of the structure of the Nafion fuel-cell membrane, of the nanocomposite in bone, and of the chain trajectories in semicrystalline polymers. Based on such structural insights, we strive to understand the materials properties and sometimes propose improved synthesis or processing conditions.
We also examine basic aspects of classical thermodynamics and of chemical energy. For instance, we have worked out quantitatively how batteries store energy in weak bonds of certain metals and release it when stronger bonds are formed, and that fire is hot due to chemical energy stored in oxygen molecules, regardless of the organic fuel. This has revealed fundamental misconceptions in traditional explanations of bioenergetics.
Courses Taught
| CHEM | 15b | Honors General Chemistry II |
| CHEM | 91g | Introduction to Research Practice |
| CHEM | 141a | Classical and Statistical Thermodynamics |
Awards and Honors
American Physical Society Fellow (2013)
Iowa State University Award for Outstanding Career Achievement in Research (2009)
American Association for the Advancement of Science (AAAS) Fellow (2008)
Dillon Medal (Polymer Division, American Physical Society) (2001)
Alfred P. Sloan Research Fellowship (2000)
Beckman Young Investigator Award (1996)
Rudolf-Kaiser Prize (German Physical Society) (1996)
Postdoctoral Fellowship (BASF AG & German Natl. Scholarship Foundation) (1993 - 1995)
Dieter-Rampacher Prize (1991)
Dissertation "summa cum laude" (1991)
Otto-Hahn Medal of the Max-Planck Society (1991)
Diploma "with excellence" (1989)
Scholarship
X. Chen, M. Jin, P. Duan, J. Mejia, W. Chu, X. Ye, X. Cao, K. Schmidt-Rohr, M. L. Thompson, J. Mao, H. Gao. "Structural composition of immobilized fertilizer N associated with decomposed wheat straw residues using advanced NMR spectroscopy combined with 13C and 15N labeling." Geoderma (2021). (forthcoming)
D. C. Podgorski, P. Zito, A. M. Kellerman, B. A. Bekins, I. M. Cozzarelli, D. F. Smith, X. Cao, K. Schmidt-Rohr, Sasha Wagner, A. Stubbins, R. G. M. Spencer. "Hydrocarbons to Carboxyl-Rich Alicyclic Molecules: A Continuum Model to Describe Biodegradation of Petroleum-Derived Dissolved Organic Matter in Contaminated Groundwater Plumes." J. Hazard. Mater. 402. (2021): 123998.
M. Schäfer, S. Yuan, A. Petzold, R. A. Pérez-Camargo, A. J. Müller, T. Thurn-Albrecht, K. Saalwächter, K. Schmidt-Rohr. "Asymmetric co-unit crystal inclusion in statistical copolyesters." Macromolecules 54. (2021): 835-845.
Z. He, M. Guo, C. Fortier, X. Cao, K. Schmidt-Rohr. "Fourier transform infrared and solid state 13C nuclear magnetic resonance spectroscopic characterization of defatted cottonseed meal-based biochars." Modern Appl. Sci. 15. (2021): 108-121.
M. Tyufekchiev, A. Kolodziejczak, P. Duan, M. Foston, K. Schmidt-Rohr, M. Ti. "Rapid Depolymerization of Decrystallized Cellulose to Soluble Products via Ethanolysis under Mild Conditions." ChemSusChem 13. (2020): 2634-2641.
P. Duan, M. S. Lamm, F. Yang, W. Xu, D. Skomski, Y. Su, K. Schmidt-Rohr. "Quantifying Molecular Mixing and Heterogeneity in Pharmaceutical Dispersions at Sub-100-nm Resolution by Spin Diffusion NMR." Molecular Pharmaceutics 17. (2020): 3567-3580.
P. G. Mileo, S. Yuan, S. Ayala, P. Duan, R. Semino, S. M. Cohen, K. Schmidt-Rohr, G. Maurin. "Structure of the Polymer Backbones in polyMOF Materials." J. Am. Chem. Soc. 142. (2020): 10863–10868.
P. Guerra, A. Zaker, P. Duan, A. R. Maag, G. A. Tompsett, A. B. Brown, K. Schmidt-Rohr, M. T. Timko. "Analysis of Coke Formed during Zeolite-Catalyzed Supercritical Dodecane Cracking: Effect of Supercritical Water." Applied Catal. A 590. (2020): 117330.
R. M. B. O. Duarte, P. Duan, J-D. Mao, W. Chu, A. C. Duarte, K Schmidt-Rohr. "Exploring the structural features of urban water-soluble organic aerosols by advanced solid-state NMR analysis." Atmospher. Environm 230. (2020): 117503 (1-8).
S. Yuan, K. Schmidt-Rohr. "Immobilized 13C-Labeled Polyether Chain Ends Confined to the Crystallite Surface Detected by Advanced NMR." Science Advances 6. (2020): eabc0059.
S. Yuan, P. Duan, D. L. Berthier, G. León, H. Sommer, J.-Y. de Saint-Laumer, K. Schmidt-Rohr. "Multinuclear Solid-State NMR of Complex Nitrogen-Rich Polymeric Microcapsules: Weight Fractions, Spectral Editing, Component Mixing, and Persistent Radicals." Solid State NMR 106. (2020): 101650.
Schmidt-Rohr, Klaus. "Analysis of Two Definitions of the Mole That Are in Simultaneous Use, and Their Surprising Consequences." J. Chem. Educ. 97. (2020): 597-602.
Schmidt-Rohr, Klaus. "Oxygen Is the High-Energy Molecule Powering Complex Multicellular Life: Fundamental Corrections to Traditional Bioenergetics." ACS Omega 5. (2020): 2221-2233.
X. Chen, W. Chu, M. L. Thompson, D. C. Olk, X.-Y. Cao, K. Schmidt-Rohr, L. Zhang, J-D. Mao, H. Gao. "Formation of Char-like, Fused-ring Aromatic Structures from a Non-pyrogenic Pathway During Decomposition of Wheat Straw." J. Agric. Food Chem. 68. (2020): 2607-2614.
A. A. Kassie, P. Duan, E. McClure, K. Schmidt-Rohr, P. Woodward, C. R. Wade. "Postsynthetic Metal Exchange in a Metal-Organic Framework Assembled from Co(III) Diphosphine Pincer Complexes." Inorganic Chemistry 58. (2019): 3227-3236.
A. A. Kassie, P. Duan, M. Gray, K. Schmidt-Rohr, P. M. Woodward, C. R. Wade. "Synthesis and Reactivity of Zr MOFs Assembled from PNNNP-Ru Pincer Complexes." Organometallics 38. (2019): 3419-3428.
K. J. Fritzsching, P. Duan, M. A. Erik, A. M. Tibabuzo Perdomo, P. Kenny, J. J. Wilker, K. Schmidt-Rohr. "A Silk-like Protein with Organic Radicals Identified in Oyster Adhesive by Solid-State NMR." ACS Applied Bio Materials 2. (2019): 2840-2852.
M. A. Gerkman, S. Yuan, P. Duan, J. Taufan, K. Schmidt-Rohr, G. G. D. Han. "Phase transition of spiropyrans: impact of isomerization dynamics at high temperatures." Chem. Comm. 55. (2019): 5813-5816.
M. Tyufekchiev, A. Kolodziejczak, P. Duan, M. Foston, K. Schmidt-Rohr, M. Timko. "Reaction Engineering Implications of Cellulose Crystallinity and Water-Promoted Recrystallization." RCS Green Chemistry 21. (2019): 5541-5555.
P. Duan, J. C. Moreton, R. Semino, G. Maurin, S. M. Cohen, K. Schmidt-Rohr. "Polymer Infiltration into Metal-organic Frameworks in Mixed-matrix Membranes Detected In Situ by NMR." J. Am. Chem. Soc. 18. (2019): 7589-7595.
P. Duan, K. Schmidt-Rohr. "Quick, Selective NMR Spectra of C-OH Moieties in 13C-enriched Solids." Journal of Magnetic Resonance 301. (2019): 80-84.
Pu Duan, Luke Coburn, Bo Zhi, Christy L. Haynes, Klaus Schmidt-Rohr. "A molecular fluorophore in carbon dots synthesized from citric acid and ethylenediamine identified and quantified by multinuclear solid-state NMR." Magn. Reson. Chem 58. (2019): 1130-1138.
W. Chu, X. Cao, K. Schmidt-Rohr, J. E. Birdwell, J. Mao. "Investigation into the Effect of Heteroatom Content on Kerogen Structure Using Advanced 13C Solid-State Nuclear Magnetic Resonance Spectroscopy." Energy & Fuels 33. (2019): 645-653.
X. Cao, F. Xiao, P. Duan, J. J. Pignatello, J. Mao, K. Schmidt-Rohr. "Effects of Post-Pyrolysis Air Oxidation on the Chemical Composition of Biomass Chars Investigated by Solid-State NMR Spectroscopy." Carbon 153. (2019): 173-178.
B. Reiner, N. T. Mucha, A. Rothstein, J. S. Temme, P. Duan, K. Schmidt-Rohr, B. M. Foxman, C. R. Wade. "Zirconium Metal–Organic Frameworks Assembled from Pd and Pt PNNNP Pincer Complexes: Synthesis, Postsynthetic Modification, and Lewis Acid Catalysis." Inorganic Chemistry 57. (2018): 2663-2672.
B. Zhang, Y. Zhang, S. Yao, X. Cao, K. Schmidt-Rohr, D. C. Olk, J. Mao. "Renewal of Soil Organic Matter structure through microbial mediation in topsoil and subsoils." Soil Biology & Biochemistry 119. (2018): 63-73.
J. Huo, P. Duan, H. N. Pham, Y. J. Chan, A. K. Datye, K. Schmidt-Rohr, B. H. Shanks. "Improved hydrothermal stability of Pd nanoparticles on nitrogen-doped carbon supports." Catalyst Science & Technology 8. (2018): 3548-3561.
J. Huo, R. L. Johnson, P. Duan, H. N. Pham, D. Mendivelso-Perez, E. A. Smith, A. Datye, K. Schmidt-Rohr, B. H. Shanks. "Stability of Pd Nanoparticles on Carbon-Based Supports under Hydrothermal Conditions." Catalysis Science & Technology 8. (2018): 1151-1160.
M. Tyufekchiev, P. Duan, K. Schmidt-Rohr, S. Granados Focil, M. T. Timko, M. H. Emmert. "Cellulase-Mimetic Solid Acids for Cellulose Hydrolysis: Structural Explanations of High Catalytic Activity." ACS Catalysis 8. (2018): 1464-1468.
P. Duan, X. Cao, H. N. Pham, A. Datye, K. Schmidt-Rohr. "Carbon overlayers from 2,3-naphthalenediol pyrolysis on mesoporous SiO2 and Al2O3 studied by solid-state NMR." Materials 11. (2018): Article # 980.
P. Duan, X. Li, S. J. Juhl, B. Chen, D. Koeplinger, V. H. Crespi, J. V. Badding, K. Schmidt-Rohr. "The Chemical Structure of Carbon Nanothreads Analyzed by Advanced Solid-State NMR." Journal of the American Chemical Society 140. (2018): 7658-7666.
Schmidt-Rohr, Klaus. "How Batteries Store and Release Energy: Explaining Basic Electrochemistry." Journal of Chemical Education 95. (2018): 1801-1810.
T. Wang, P. Duan, Xu, E., B. Vermilyea, B. Chen, X. Li, J. V. Badding, K. Schmidt-Rohr, V. H. Crespi. "Constraining Nanothread Structures with Experimental and Calculated Nuclear Magnetic Resonance Spectra." Nano Letters 18. (2018): 4934-4942.
X. Cao, G. R. Aiken, K. D. Butler, J. Mao, K. Schmidt-Rohr. "Comparison of the Chemical Composition of Dissolved Organic Matter in Three Lakes in Minnesota." Environmental Science & Technology 52. (2018): 1747-1755.
X. Cao, K. Schmidt-Rohr. "Abundant Nonprotonated Aromatic and Oxygen-Bonded Carbons Make Humic Substances Distinct from Biopolymers." Environmental Science & Technology Letters 5. (2018): 476-480.
X. Li, T. Wang, P. Duan, M. Baldini, H.-T. Huang, B. Chen, D. Koeplinger, V. H. Crespi, K. Schmidt-Rohr, R. Hoffmann, M. Guthrie, J. V. Badding. "Carbon Nitride Nanothread Crystals Derived from Pyridine." Journal of the American Chemical Society 140. (2018): 4969-4972.
Y.-L. Zhang, L.-J. Li, S.-H. Yao, J.-D. Mao, K. Schmidt-Rohr, D. C. Olk, X.-Y. Cao, J.-F. Cui, B. Zhang. "Distinct changes in composition of soil organic matter with length of cropping time in subsoils of a Phaeozem and Chernozem." European Journal of Soil Science 68. (2018): 868-878.
C. Brewer, E. T. Hall, K. Schmidt-Rohr, D. A. Laird, R. C. Brown, K. Zygourakis. "Temperature and reaction atmosphere effects on the properties of corn stover biochar." Environ. Progress Sustain. Energy 36. (2017): 696-707.
J. Xie, P. Duan, N. Kaylor, K. Yin, B. Huang, K. Schmidt-Rohr, R. Davis. "Investigation on the formation of poisoning species over supported Pt catalysts during alcohol oxidation reaction." ACS Catalysis 7. (2017): 6745-6756.
K. J. Fritzsching, K. Mao, K. Schmidt-Rohr. "Avoidance of Density Anomalies as a Structural Principle for Semicrystalline Polymers: The Importance of Chain Ends and Chain Tilt." Macromolecules 50. (2017): 1521-1540.
Mao, J.-D., X. Cao, D. C. Olk, W. Chu, K. Schmidt-Rohr. "Advanced solid-state NMR spectroscopy of natural organic matter." Prog. Nucl. Magn. Reson. Spectros. 100. (2017): 17-100.
N. Zhou, X. Cao, X. Du, H. Wang, M. Wang, S. Liu, K. Nguyen, K. Schmidt-Rohr, Q. Xu, G. Liang, B. Xu. "Hyper-Crosslinkers Lead to Temperature- and pH-Responsive Polymeric Nanogels with Unusual Volume Change." Angew. Chem. Int. Ed. 56. (2017): 1-6.
P. Duan, K. Schmidt-Rohr. "Composite-Pulse and Partially Dipolar Dephased MultiCP for Improved Quantitative Solid-State 13C NMR." Journal of Magnetic Resonance 285. (2017): 68-78.
X. Cao, G. R. Aiken, K. D. Butler, T. G. Huntington, W. M. Balch, J. Mao, K. Schmidt-Rohr. "Evidence of Major Input of Riverine Organic Matter into the Ocean." Organic Geochemistry 116. (2017): 62-76.
X. Cao, M. R. Mulholland, J. R. Helms, P. W. Bernhardt, P. Duan, J. Mao, K. Schmidt-Rohr. "A Major Step in Opening the Black Box of High-Molecular-Weight Dissolved Organic Nitrogen by Isotopic Labeling of Synechococcus and Multi-Bond Two-Dimensional NMR." Analytical Chemistry 89. (2017): 11990-11998.
E. M. Levin, J.-F. Cui, K. Schmidt-Rohr. "Sub-millisecond 125Te NMR spin-lattice relaxation times and large Knight shifts in complex tellurides: validation of a quadratic relation across the spectrum." Solid State NMR (2016).
H. Wang, Z. Feng, D. Wu, K. J. Fritzsching, M. Rigney, J. Zhou, Y. Jiang, K. Schmidt-Rohr, B. Xu. "Enzyme-Regulated Supramolecular Assemblies of Cholesterol Conjugates against Drug-Resistant Ovarian Cancer Cells." J. Am. Chem. Soc. 138. (2016): 10758-10761.
K. J. Fritzsching, M. Hong, K. Schmidt-Rohr. "Conformationally Selective Multidimensional Chemical Shift Ranges in Proteins from a PACSY Database Purged Using Intrinsic Quality Criteria." J. Biomol. NMR 64. (2016): 115-130.
R. J. Comito, K. J. Fritzsching, B. J. Sundell, K. Schmidt-Rohr, M. Dinca. "Single-Site Heterogeneous Catalysts for Olefin Polymerization Enabled by Cation Exchange in a Metal-Organic Framework." J. Am. Chem. Soc. 138. (2016): 10232-10237.
R.L. Johnson, T. J. Schwartz, J. A. Dumesic, K. Schmidt-Rohr. "Methionine Bound to Pd/γ-Al2O3 Catalysts Studied by Solid-State 13C NMR." Solid State NMR 72. (2016): 118-126.
S. Burgess, A. Kassie, S. Baranowski, K. J. Fritzsching, K. Schmidt-Rohr, C. Brown, C. Wade. "Improved Catalytic Activity and Stability of a Palladium Pincer Complex by Incorporation into a Metal-organic Framework." J. Am. Chem. Soc. 138. (2016): 1780-1783.
X-Y. Cao, C. Lattao, K. Schmidt-Rohr, J-D. Mao, J. J. Pignatello. "Investigation of Sorbate-Induced Plasticization of Pahokee Peat by Solid-State NMR Spectroscopy." J. Soil Sediments 16. (2016): 1841-1848.
X-Y. Cao, G. R. Aiken, R. G. Spencer, J-D. Mao, K. Schmidt-Rohr. "Novel insights from NMR spectroscopy into seasonal changes in the composition of dissolved organic matter exported to the Bering Sea by the Yukon River." Geochim. Geophys. Acta 181. (2016): 72-88.
E.M. Levin, K. Schmidt-Rohr, J. Cui, R. Hanus, T. Riedermann, Q. Xing, T. Lograsso. "Phase analysis and determination of local charge carrier concentration in multiphase magnesium-silicide system." Materials Chemistry and Physics 158. (2015): 1-9.
H. Pham, A. E. Anderson, R. L. Johnson, T. J. Schwartz, B. J. O’Neill, P. Duan, K. Schmidt-Rohr, J. A. Dumesic, A. K. Datye. "Carbon Overcoating of Supported Metal Catalysts for Improved Hydrothermal Stability." ACS Catalysis 5. (2015): 4546-4555.
J. K. Williams, K. Schmidt-Rohr, M. Hong. "Aromatic spectral editing techniques for magic-angle spinning solid-state NMR spectroscopy of uniformly 13C-labeled proteins." Solid State NMR 72. (2015): 118-126.
K. Schmidt-Rohr, J. Cui. "Reply to a Comment on “Quantification of C=C and C=O Surface Carbons in Nanodiamond by NMR”." J. Phys. Chem. C 119. (2015): 21288–21291.
Schmidt-Rohr, Klaus. "Why Combustions Are Always Exothermic, Yielding About 418 kJ per Mole of O_2." J. Chem. Educ. 92. (2015): 2094-2099.
T. Wang, J. K. Williams, K. Schmidt-Rohr, M. Hong. "Relaxation-Compensated Difference Spin Diffusion NMR for Detecting 13C-13C Long-Range Correlations in Proteins and Polysaccharides." Journal of Biomolecular NMR 61. (2015): 97-107.
Zhang, Honghu; Liu, Xunpei; Feng, Shuren; Wang, Wenjie; Schmidt-Rohr, Klaus; Akinc, Mufit; Nilsen-Hamilton, Marit; Vaknin, David; Mallapragada, Surya. "Morphological Transformations in the Magnetite Biomineralizing Protein Mms6 in Iron Solutions: A Small-Angle X-ray Scattering Study." Langmuir 31. (2015): 2818-2825.
C. Lattao, X-Y. Cao, J-D. Mao, K. Schmidt-Rohr, J. Pignatello. "Influence of Molecular Structure and Adsorbent Properties on Sorption of Organic Compounds to a Temperature Series of Wood Chars." Environmental Science & Technology 48. (2014): 4790-4798.
J-F. Cui, X-W. Fang, K. Schmidt-Rohr. "Quantification of C=C and C=O Surface Carbons in Nanodiamond by NMR." Journal of Chemical Physics C 118. (2014): 9612-9627.
J. M. Anderson, R. L. Johnson, K. Schmidt-Rohr, B. H. Shanks. "Hydrothermal Degradation of Model Sulfonic Acid Compounds: Probing the Relative Sulfur–Carbon Bond Strength." Catalysis Communications 51. (2014): 33-36.
J. M. Anderson, R. L. Johnson, K. Schmidt-Rohr, B. H. Shanks. "Solid State NMR of Chemical Structure and Hydrothermal Deactivation of Moderate-Temperature Carbon Materials with Acidic SO3H Sites." Carbon 74. (2014): 333-345.
J. R. Helms, J-D. Mao, A. Stubbins, K. Schmidt-Rohr, R. Spencer, P. Hernes, K. Mopper. "Loss of optical and molecular indicators of terrigenous dissolved organic matter during long-term photobleaching." Aquatic Sciences 76. (2014): 353-373.
Levin, Evgenii, Kramer, M., Schmidt-Rohr, Klaus. "Local Composition and Carrier Concentration in Pb0.7Ge0.3Te and Pb0.5Ge0.5Te Alloys from 125Te NMR and Microscopy." J. Phys. Chem. Solids 75. (2014): 4790-4798.
R. L. Johnson, J. M. Anderson, B. H. Shanks, Schmidt-Rohr, Klaus. "Simple one-step synthesis of aromatic-rich materials with high concentrations of hydrothermally stable catalytic sites, validated by NMR." Chemistry of Materials 26. (2014): 5523-5532.
T. Schwartz, R. L. Johnson, J. Cardenas, A. Okerlund, N. A. DaSilva, K. Schmidt-Rohr, J. Dumesic. "Engineering Catalyst Microenvironments for Metal-Catalyzed Hydrogenation of Biologically-Derived Platform Chemicals." Angewandte Chemie, International Edition 53. (2014): 12718-12722.
X-Y. Cao, C. Lattao, J. Pignatello, J-D. Mao, Schmidt-Rohr, Klaus. "Sorption Selectivity in Natural Organic Matter Probed with Carbonyl-13C-Labeled Benzophenone and 1H-13C NMR Spectroscopy." Environ. Sci. Technol. 48. (2014): 8645-8652.
Z. Zhou, X. Cao, K. Schmidt-Rohr, D. C. Olk, S. Zhuang, J. Zhou, Z. Cao, J-D. Mao. "Similarities in chemical composition of soil organic matter across a millennia-old paddy soil chronosequence as revealed by advanced solid-state NMR spectroscopy." Biol. Fertil. Soils 50. (2014): 571-581.