Session PK. There are 22 abstracts in this session.

Session: Materials and Inorganics, poster number: 306
Revealing binding secrets of mussel-mimetic adhesive domain on nanoparticle surface by using solution state NMR spectroscopy
Narendra Venkatareddy
Humboldt University of Berlin, Berlin, Germany
Bio-inspired peptides that mimic the functions mussel adhesive protein’s can show strong and selective adhesion to inorganic surfaces under ambient conditions and outperform technical wet-glues for potential biomedical applications. However, the molecular basis of peptide interactions toward inorganic surfaces is not yet entirely understood. In the present contribution, we report a solution NMR spectroscopy study revealing insights into interactions of mussel-inspired peptides, showing sequence-specific and strong adhesion onto Al2O3 nanoparticle surfaces.Nuclear Overhauser Effect (NOE) based ligand-receptor screening methods such as Saturation Transfer Difference (STD) and NOESY experiments were applied to understand the orientation and bound structure of the peptide on the surface.

Session: Materials and Inorganics, poster number: 307
Probing the Surface of γ-Al2O3 by Oxygen-17 Dynamic Nuclear Polarization Enhanced Solid-State NMR Spectroscopy
Qiang Wang1; Wenzheng Li1; Jun Xu1; Fabien Aussenac2; Guodong Qi1; Chao Wang1; Feng Deng1
1Wuhan Inst. of Physics and Mathematics, CAS, Wuhan, China; 2Bruker Biospin SAS F-67160, Wissembourg, France
We show that (sub-)surface oxygen species of γ-Al2O3 can be rapidly detected by 17O dynamic nuclear polarization (DNP) surface-enhanced solid-state NMR spectroscopy. The 17O DNP-SENS solid-state NMR spectroscopy coupled with 17O isotope enrichment can provide detailed structural information on the (sub-) surface oxygen species of γ-Al2O3. The oxygen sites with (hydroxyl groups) or without (bare oxygen) bonded protons were clearly differentiated by direct 17O and 1H→17O CP DNP. Furthermore, well-resolved 2D 17O MQMAS and 1H→17O HETCOR spectra were obtained, which allows us to readily identify the (sub-)surface oxygen species.The oxygen species with and without bonded protons are well differentiated.

Session: Materials and Inorganics, poster number: 308
13C and 15N NMR on solid amine modified SBA15 (Carbon capture)
Chia-Hsin Chen1; Daphna Shimon2; Jason J. Lee3; Carsten Sievers3; Christopher W. Jones3; Sophia E. Hayes1
1Washington University in St. Louis, St. Louis, MO; 2Dartmouth College, Hanover, NH; 3Georgia Institute of Technology, Atlanta, GA
Solid-state NMR is being used to evaluate materials being designed for CO2 capture. These are solid-amine sorbents, consisting of pendant amine molecules that are covalently attached to SBA-15. By using isotopically-enriched 13CO2, we obtain with isotopic labeled products: carbamate, carbamic acid, or bicarbonate. Here, we present the characterization of the 13CO2 chemisorbed products arising from different types of amines, including primary, secondary and tertiary amine. 13C and 15N CPMAS of chemisorbed products will be discussed as well as 13C –1H HETCOR data. We have found that cross-polarization contact time curves to determine TIS and T time constants are informative for 15N. By observing evolution of chemisorbed products by 13C and 15N NMR spectroscopy could give more understanding of adsorption/desorption process.

Session: Materials and Inorganics, poster number: 309
Quantitative NMR Analysis through Polarization Transfer and its Applications
Jianbo Hou; Yiyong He; XiaoHua Qiu; Donald Eldred; Susan Zong
The Dow Chemical Company, Midland, MI
Polarization transfer (such as INEPT and DEPT) is a well-recognized way to enhance sensitivity for NMR spectra. However, the spectral quality (phase distortion) and non-quantitative feature of polarization transfer limits its applications. On the other side, for industrial research and QC control, quantitative analysis is one of the critical requirements. Recently we reported a novel NMR methodology that enables accurate composition analysis of polyolefin materials in a fast and robust manner. The method is named quantitative adiabatic refocused insensitive nuclei enhanced by polarization transfer (QA-RINEPT).
This is a continued study to show that applications of QA-RINEPT can be extended to beyond compositional analysis, and beyond 13C NMR. The benefits of QA-RINEPT vs. traditional single pulse experiment will be presented.

Session: Materials and Inorganics, poster number: 310
Understanding Nanoparticle Surface Interactions Using Saturation-Transfer Difference (STD)-NMR
Leah Casabianca
Clemson University, Clemson, SC
Development of NMR methods that can be used to examine the structure of molecules interacting with the surface of nanoparticles is important to understanding nanoparticle transport and toxicity. Saturation-Transfer Difference (STD)-NMR is a ligand-detected solution-state NMR technique that has proven utility in detecting small molecule ligands binding to protein receptors.  Here we present our results of using STD-NMR to examine the adsorption of small molecules such as alcohols, dyes, and peptides on the surface of polystyrene nanoparticles of various sizes.

Session: Materials and Inorganics, poster number: 311
Solid State NMR Study of Periosteum Extracellular Matrix-mediated Acellular Mineralization
PEIZHI ZHU
Yangzhou University, Yangzhou, JS
Cell-mediated mineralization is essential for bone formation and regeneration. Using decellularized periosteum scaffold, we revealed that ECM scaffold itself could promote critical bone defect regeneration and nude mouse ectopic ossification. The natural collagen matrix of decellularized periosteum can serve as a three-dimensional (3D) structural template for Ca-P nuclei initiation, controlling the size and orientation of bone-like mineral crystals. The naturally cross-linked and highly-ordered 3D fibrillar network of decellularized periosteum not only provides a model for mimicking mineralization in vitro and in vivo to elucidate the important functions of ECM in bone formation and regeneration but also could be a promising biomaterial for bone tissue engineering and clinical application.

Session: Materials and Inorganics, poster number: 312
Resolving segmental mobility in starch phase transitions using polarization transfer solid-state NMR
Agnieszka Nowacka1; Thomas Steglich2, 3; Daniel Topgaard1; Diana Bernin4, 5
1Department of Chemistry, Lund University, Lund, Sweden; 2Structure and Material Design, Rise, Gothenburg, Sweden; 3Department of Food Science, SLU, Uppsala, Sweden; 4Chem Process and Reaction Engineering, Chalmers, Gothenburg, Sweden; 5Swedish NMR Centre, University of Gothenburg, Gothenburg, Sweden
Most starch-based staple food requires heating while being immersed in a fluid to become digestible for humans. On a molecular level, starch then undergoes a phase transition called gelatinization, which has been extensively studied using DSC and diffraction, reporting contradictory results. We applied polarization transfer solid-state NMR on starch-water mixtures with low and intermediate water content as a function of temperature. The polarization transfer signal intensities are used to access the segmental mobility of the polysaccharide chains: a direct measure of gelatinization. We observed smooth transitions independently of the water content, meaning that crystalline and amorphous chain segments with correlation times longer than milliseconds turned into mobile segments with correlation times on the nanosecond time scale.

Session: Materials and Inorganics, poster number: 313
Molecular Orientation Distribution in Regenerated Cellulose Fibers
Leo Svenningsson
Chalmers uni. of technology, Göteborg, Sweden
Morphology of regenerated cellulose fibers is known to affect mechanical properties along with chemical accessibility and appearance. One essential part of the morphology description is to determine the molecular orientation distribution function of the cellulose chain segments, which are typically aligned in the fibers drawing direction. Using solid-state NMR spectroscopy and the intrinsic chemical shielding tensor properties, it is possible to probe molecular anisotropy and thereby the molecular orientation. The methodology is based on Rotor Synchronized Magic Angle Spinning, abbreviated ROSMAS, which was originally developed by Spiess and co-workers and conducted on polyethylene terephthalate along with other synthetic polymers. The data evaluation strongly depends on an accurate chemical shielding tensor description and therefore we have employed density functional theory (DFT) electronic structure calculations, using the gauge-independent atomic orbital method, to minimize the identified inconsistency in previously reported data. Our results were compared with X-ray diffraction, polarized Raman spectroscopy and birefringence analysis to establish a better understanding and to eliminate potential errors attributed which each technique.

Session: Materials and Inorganics, poster number: 314
Atomic-level crystallization, adsorption, and reaction properties of zeolite catalysts established by solid-state J-mediated DNP-NMR and synchrotron XRPD  
Zachariah Berkson1; David Gajan2; Anne Lesage2; Stef Smeets3, 4; Christian Baerlocher1, 3; Lynne McCusker1, 3; Brad Chmelka1
1UCSB, Santa Barbara, CA; 2ISA-CRMN, Villeurbanne, France; 3ETH Zurich, Zurich, Switzerland; 4Stockholm University, Stockholm, Sweden
Dynamic-nuclear-polarization (DNP-)NMR techniques that exploit through-bond J interactions, in combination with synchrotron X-ray powder diffraction (XRPD), enable analyses of framework structures and adsorption/reaction sites in new heterogeneous zeolite catalysts with emerging applications in hydrocarbon conversion. Two-dimensional (2D) 29Si{29Si} and 27Al{29Si} J-mediated NMR spectra of new mesostructured zeolites and industrially-promising zeolite SSZ-70, with signal sensitivity enhanced by low temperature (<100 K) and/or DNP-NMR methods, unambiguously distinguish covalent 29Si and 27Al bonding environments to determine their atomic-scale structures and compositions. The analyses enable direct characterization of atomic rearrangement processes that occur during zeolite crystallization and yield new insights into the structures and heteroatom distributions in highly active zeolite catalysts, elucidating the atomic-scale origins of their catalytic properties.

Session: Materials and Inorganics, poster number: 315
11B and 14N Investigations of Boron Nitride Nanotubes: New insights from Quadrupolar Lineshapes, Chemical Shieldings, and Density Functional Theory Calculations
Alexander Greenwood1; Mahmoud Amin1; Riqiang Fu2; Myriam Cotten1; Robert Vold1; Hannes Schniepp1
1College of William and Mary, Williamsburg, Virginia; 2National High Magnetic Field Laboratory, Tallahassee, FL
Boron nitride nanotubes (BNNT) are composed of rolled-up sheets of hexagonal boron nitride (hBN), which has a hexagonal lattice structure similar to graphene but with alternating boron and nitrogen atoms instead of carbon. Because of their exceptional physical properties, there is a growing interest in developing methods to characterize the atomic-scale structure of BNNT. Density Functional Theory (DFT) calculations were performed on a series of single-wall BNNT models of varying diameters to calculate the electric field gradients at the 14N and 11B sites, as well as the chemical shieldings of each nucleus. We report the results of these calculations and compare to values experimentally-measured at magnetic field strengths varying from 7.05 to 21.1T.

Session: Materials and Inorganics, poster number: 316
Surface Structure Determination of Heterogeneous Catalysts by DNP SENS
Ribal Jabbour1; Pierrick Berruyer1; David Gajan1; Marc Renom-Carrasco1; Moreno Lelli2; Christophe Copéret3; Chloé Thieuleux1; Lyndon Emsley4; Anne Lesage1
1University de Lyon, Lyon, France; 2University of Florence, Florence, Italy; 3ETH, Zürich, Switzerland; 4EPFL, Lausanne, Switzerland
Here 
we investigate the 3D structure of an Iridium N-heterocyclic carbene hybrid material, extremely efficient in alkene hydrogenation, using a DNP enhanced solid-
state NMR spectroscopy approach
. The synthesis of this catalyst relies on the incorporation of Ir onto supported NHC ligands via a series of surface chemical reactions. The conversion of the ligands is however incomplete. We will propose a structure determination protocol compatible with a multisite surface. In particular, the implementation of conventional and selective REDOR schemes allows one to obtain long-range 29Si-13C, 13C-15N and 29Si-15N distances (up to 6.5 Å) on both the precursors and the Ir catalytic materials. The resulting structures are expected to contribute to a rational understanding of the outstanding  activity of this catalyst.

Session: Materials and Inorganics, poster number: 317
Boosting Sensitivity and Suppressing Artifacts via Multi-Acquisition in Direct Polarization NMR Experiments with Small Flip-Angle Pulses
Riqiang Fu1; Arturo Hernández-Maldonado2
1National High Magnetic Field Laboratory, Tallahassee, FL; 2University of Puerto Rico at Mayaguez, Mayaguez, PR 00681-9000
A multi-acquisition scheme is proposed to boost the sensitivity per scan while effectively suppress these artifacts. Here, an adiabatic inversion pulse is first applied to bring the magnetization down to the –z axis and then a small flip-angle pulse excitation is applied before the data acquisition. Immediately after, the adiabatic inversion pulse is applied to flip the magnetization back to the +z axis, followed by a second data acquisition after another small flip-angle pulse excitation. The difference between the two consecutive acquisitions cancels out any artifacts, while the wanted signals are accumulated. This acquisition process can be repeated many times before going into next scan. Therefore, by acquiring the signals multiple times in a single scan the sensitivity is improved.

Session: Materials and Inorganics, poster number: 318

Investigating Disorder and Dynamics in a Novel Gallophosphate


Joseph Hooper1; Daniel Dawson1; Lucy Broom2; Mahrez Amri2; Richard Walton2; Sharon Ashbrook1
1University of St Andrews, St Andrews, United Kingdom; 2University of Warwick, Coventry, United Kingdom

An unknown gallophosphate has been observed as a competing phase in the synthesis of GaPO-34. However, proposed structural models do not adequately describe the disorder present, as highlighted by the solid-state NMR spectra obtained. DFT calculations have been employed to provide insights into the F/OH disorder and to assist in the assignment of multinuclear and multidimensional NMR spectra. The combination of NMR, XRD and DFT calculations have proved to be a powerful tool for obtaining a detailed structural picture of this highly disordered material.


Session: Materials and Inorganics, poster number: 319
NMR Crystallography: Refinement of Multiple Proton Positions in Hydrated Magnesium Carbonate through 13C{1H} REDOR and Density Functional Theory Calculation
Jinlei Cui1; David Olmsted2; Anil K. Mehta3; Mark Asta2; Sophia E. Hayes1
1Washington University, Saint Louis, MO; 2University of California, Berkeley, Berkeley, CA; 3Emory University, Atlanta, GA
Capture of CO2 and storage as a solid-state mineral is a permanent solution for reducing atmospheric CO2 level. The hydrated magnesium carbonate species is one form on the way to the MgCO3 "endmember". Our recent study provides fundamental insights in applying nuclear magnetic resonance (NMR) crystallography on hydrated mineralization products. Solid-state NMR and rotation echo double resonance (REDOR) are used to characterize 13C chemical shift anisotropy (CSA) and dipolar coupling between 13C and surrounding protons, respectively. Density function theory is used to calculate NMR tensors from an X-ray diffraction (XRD) crystal structure. The combination of REDOR and CSA analysis, XRD and computational chemistry is proven to be useful for determining protons positions. This is a significant improvement for hydrated minerals.

Session: Materials and Inorganics, poster number: 320
Purpurin-Functionalized Polystyrene as a Potential Lithium Ion Battery Material
Hsin Wang; Mikhail Miroshnikov; George John
CUNY - City College, New York, NY
As a potential green technology alternative to the traditional lithium ion battery materials, purpurin’s lithium storage property was recently explored and demonstrated. Purpurin is now chemically functionalized onto lightly cross-linked chloromethylated polystyrene (PS) to increase the electrochemical cycling stability and efficiency. Efforts have been made to increase the purpurin loading capacity, and thus the lithium storage capacity via the control of chloromethylpolystyrene. The resultant purpurin-functionalized PS and their lithiated products have been characterized with solid-state C13 and Li7 NMR spectroscopy, and compared with solution-state NMR studies of similar purpurin-derived compounds. The electrochemical study is ongoing at our collaborators’ laboratory.

Session: Materials and Inorganics, poster number: 321
7Li MRI Probing Li Distribution Homogeneity in All-Solid-State Batteries
Mingxue Tang
NHMFL, Tallahassee, FL
All-solid-state rechargeable batteries embody the promise for high energy density, increased stability, and improved safety. However, the high resistance for mass and charge transfer at electrode-electrolyte interfaces prevents them from practical applications. Li deficiency at interfaces has been proposed as one of the main mechanisms causing high interfacial resistance. Yet the experimental evidence is elusive due to the challenges associated with non-invasively probing Li distribution in solid electrolytes. 7Li magnetic resonance imaging (MRI) and the derived histograms of Li density reveal Li depletion from the electrode-electrolyte interfaces and increased heterogeneity of Li distribution in the bulk Li10GeP2S12 upon electrochemical cycling. Li deficiency at electrode-electrolyte interfaces is determined as the dominant cause for high interfacial resistance.

Session: Materials and Inorganics, poster number: 322
Atomic-Scale Structure of Mesoporous Silica-Encapsulated Pt and Pt-Sn Nanoparticles Revealed by Dynamic Nuclear Polarization-Enhanced Si-29 NMR Spectroscopy
Tommy Yunpu Zhao
University of Florida, Gainesville, Florida
Mesoporous silica (mSiO2) encapsulated Pt-Sn nanoparticles (NPs) are a new class of tunable heterogeneous catalysts with uniform particle size, enhanced catalytic properties, and superior thermal stability. However, the atomic-scale structure within its mSiO2 shell has not been previously examined. Here, the quaternary Q2, Q3 and Q4 sites corresponding to formulas Si(O1/2)2(OH)2, Si(O1/2)3(OH)1 and Si(O1/2)4, were identified and quantified by conventional Magic Angle Spinning (MAS) NMR at room temperature in both Pt@mSiO2 and PtSn@mSiO2, and the spatial distribution of the quaternary sites are revealed by direct and indirect Dynamic Nuclear Polarization (DNP)-enhanced 29Si MAS NMR spectroscopy. Furthermore, the atomic connectivity among the Qx sites was revealed by DNP-enhanced two-dimensional 29Si-29Si correlation spectroscopy.

Session: Materials and Inorganics, poster number: 323
Hydroxyl-Proton Selection (HOPS) - A Convenient Method for Selective NMR of COH Moieties
Pu Duan; Klaus Schmidt-Rohr
Brandeis University, Waltham, MA
A convenient 1D NMR method is introduced that provides selective NMR spectra of COH moieties in uniformly 13C-enriched organic materials. This method, termed hydroxyl-proton selection (HOPS), eliminates the magnetization of protons bonded to carbons by recoupling the 1H-13C dipolar interaction for a short time (~70 μs), which also serves as a chemical-shift filter to suppress 1H magnetization of CH3 groups. After CP to 13C, the signals of C-OH and COOH carbons are observed selectively. This makes it possible to distinguish alcohols from ethers, in particular phenols from aromatic ethers such as the furans often formed by dehydration of glucose, and carboxylic acids from carboxylates and ethers. HOPS NMR reveals that orthodiphenols are often a major component of low-temperature carbon materials.

Session: Materials and Inorganics, poster number: 324
Synthesis and Characterization of Tunable High Dense Peptide Functionalized Nano Channels: A solid state CP-MAS-NMR and DNP-NMR Study
Martin Brodrecht; Bharti Kumari; Hergen Breitzke; Torsten Gutmann; Gerd Buntkowsky
Technische Universität Darmstadt, Darmstadt, Germany
Highly ordered amino-functionalized SBA-15 materials were synthesized by an optimized co-condensation method. The ordered pore systems were further functionalized with amino acids to mimic phyisco-chemical properties of biological pores or membranes. The success of functionalization was investigated by 13C and 29Si CP MAS and 15N DNP solid state NMR. Changes of the specific surface area, pore volume and pore diameters were investigate by nitrogen adsorption-desorption measurements (BET).The combination of the analytical methods provide information on the exact grafting density, chemical changes on the pore surface and pore properties of the material during the different functionalization steps. This universal synthesis approach combined with multinuclear solid state NMR provides information to understand their structure functionality relationship.

Session: Materials and Inorganics, poster number: 325
Uniform Driven Equilibrium Fourier Transform (U-DEFT) for SSNMR of 29Si spectra
Julien Trebosc1; Nghia Duong3; Jean Paul Amoureux2; Olivier Lafon2
1Institut Chevreul, CNRS FR2638, Lille university, Villeneuve d'Ascq, France; 2UCCS, CNRS UMR8181, Lille university, Villeneuve d'Ascq, France; 3RIKEN CLST-JEOL Collaboration Center, yokohama, japan
The DEFT is an old idea that was improved lately. However application has mostly been done in liquids. Here we show that it is suitable to improve sensitivity in SSNMR of 29Si direct observation. Indeed, 29Si has low abundance, long longitudinal relaxation and is usually submitted to large chemical shift distribution although it seldom spans over more than 100ppm. More importantly its CSA remains within limited spread that can easily overcome with reasonable MAS speed. We show that sensitivity can be increased significantly in a broad range of materials, from mesoporous silica to protonated and mobile polymers. We analyse the limiting factors to sensitivity, try to overcome them and give direction to achieve best S/N or reliable quantitative spectra

Session: Materials and Inorganics, poster number: 326

Solid-state NMR studies on high-performance Li/Na cathode materials


Xiang Li1; Yan-Yan Hu1, 2
1Florida state university, Tallahassee, FL; 2National High Magnetic Field Laboratory, tallahassee, FL

The fast-growing demand for safe and low-cost energy storage technologies with high power and energy densities drives the continuous improvement of rechargeable Li/Na-ion batteries (LIBs/SIBs). The capacities of LIBs and SIBs are limited by cathodes. Understanding the functioning and degradation mechanisms of the materials is essential. The unique capability and obtained information of solid state NMR are discussed here. To achieve the highest resolution, MATPASS (magic-angle turning and phase-adjusted sideband separation) and QCPMG (quadrupolar Carr-Purcell-Meiboom-Gill) were mainly employed for cycled samples at different states-of-charge.


Session: Materials and Inorganics, poster number: 327
Dynamic Nuclear Polarization and Ultrafast Spinning Magic Angle Spinning NMR of Pharmaceutical Materials
Xingyu Lu1; Chengbin Huang1; Qing Zhe Ni2; Haichen Nie1; Fengyuan Yang1; Thach Can2; Ivan Sergeyev3; Suzanne D'Addio1; Yongjun Li1; Lipert P. Maya1; Gary E. Martin1; R. Thomas Williamson1; Wei Xu1; Robert G. Griffin2; Yongchao Su1
1Merck Research Laboratories, Merck & Co.,Inc, Kenilworth, NJ; 2Massachusetts Institute of Technology, Cambridge, MA; 3Bruker BioSpin Corporation, Billerica, MA
Solid dosage represents a major category of modern medications. As a noninvasive and high resolution analytical technique, ssNMR plays an indispensable role in investigating molecular structures, dynamics and interactions of solid-state materials in pharmaceutical sciences. The molecular investigation in these multicomponent and natural abundance pharmaceutical materials offers both technical challenges and opportunities for this advanced technique. Recent advances in dynamic nuclear polarization (DNP) and proton detection under ultrafast magic angle spinning (MAS) with sample rotation frequencies at 60-110 kHz open a new avenue of characterizing natural abundance pharmaceutical materials. We aim to advance these sensitivity and resolution enhanced techniques for implementing multinuclear and multidimensional ssNMR spectroscopy in pharmaceutical sciences.