%0 Journal Article %J Chemistry - An Aisan Journal %D 2018 %T Hyperpolarized NMR Spectroscopy: d‐DNP, PHIP, and SABRE Techniques %A Kirill Kovtunov %A Ekaterina Pokochueva %A Oleg Salnikov %A Samuel Cousin %A Dennis Kurzbach %A Basile Vuichoud %A Sami Jannin %A Eduard Chekmenev %A Boyd Goodson %A Danila Barskiy %A Igor Koptyug %X

The intensity of NMR signals can be enhanced by several orders of magnitude by using various techniques for the hyperpolarization of different molecules. Such approaches can overcome the main sensitivity challenges facing modern NMR/magnetic resonance imaging (MRI) techniques, whilst hyperpolarized fluids can also be used in a variety of applications in material science and biomedicine. This Focus Review considers the fundamentals of the preparation of hyperpolarized liquids and gases by using dissolution dynamic nuclear polarization (d‐DNP) and parahydrogen‐based techniques, such as signal amplification by reversible exchange (SABRE) and parahydrogen‐induced polarization (PHIP), in both heterogeneous and homogeneous processes. The various new aspects in the formation and utilization of hyperpolarized fluids, along with the possibility of observing NMR signal enhancement, are described.

 

%B Chemistry - An Aisan Journal %V 13 %8 08/2018 %G eng %U https://onlinelibrary.wiley.com/doi/abs/10.1002/asia.201800551 %N 15 %R 10.1002/asia.201800551 %0 Journal Article %J Phys. Rev. B Rapid Communications %D 2018 %T Optically-pumped dynamic nuclear hyperpolarization in 13C enriched diamond %A Parker, AJ %A Jeong, K %A Avalos, CE %A Hausmann, BJM %A Vassiliou, CC %A Pines, A %A King, JP %X

We investigate nuclear spin hyperpolarization from optically polarized nitrogen vacancy centers in isotopically enriched diamonds with 13C concentrations up to 100%. 13C enrichment leads to hyperfine structure of the nitrogen vacancy electron spin resonance spectrum and dynamic nuclear polarization enhancement profile. We show that strongly-coupled \cthirt spins in the first shell surrounding a nitrogen vacancy center generate resolved hyperfine splittings, but do not act as an intermediary in the transfer of hyperpolarization of bulk nuclear spins. High levels of \cthirt enrichment are desirable to increase the efficiency of hyperpolarization for magnetic resonance signal enhancement, imaging contrast agents, and as a platform for quantum sensing and many-body physics.

%B Phys. Rev. B Rapid Communications %G eng %U https://journals.aps.org/prb/accepted/0707cOeaT9fE2916845f0be02a174d447e77534ff %0 Journal Article %J Scientific Reports %D 2017 %T An optimized microfabricated platform for the optical generation and detection of hyperpolarized 129Xe %A Daniel J. Kennedy %A Scott J. Seltzer %A Ricardo Jimenez-Martinez %A Hattie L. Ring %A Nicholas Malecek %A Svenja Knappe %A Elizabeth Donley %A John Kitching %A Vikram S. Bajaj %A Alexander Pines %B Scientific Reports %G eng %U http://www.nature.com/articles/srep43994 %0 Journal Article %J J. Phys. Chem. C %D 2017 %T Understanding the magnetic resonance spectrum of nitrogen vacancy centers in an ensemble of randomly-oriented nanodiamonds %A Jeong, K %A Parker, AJ %A Page, RH %A Pines, A %A Vassiliou, C %A King, JP %B J. Phys. Chem. C %G eng %0 Journal Article %J JACS Communication %D 2016 %T 129Xe NMR Relaxation-Based Macromolecular Sensing %A Muller Gomes %A Phuong Dao %A Keunghong Jeong %A Clancy Slack %A Christophoros Vassiliou %A Matthew B. Francis %A David Wemmer %A Alexander Pines %B JACS Communication %V 138 %8 07/2016 %G eng %N 31 %& 9747 %0 Journal Article %J Chemical Communications %D 2016 %T Rotaxane probes for protease detection by 129Xe hyperCEST NMR %A Slack, CS %A Finbloom, JA %A Jeong, K %A Bruns, CJ %A Wemmer, DE %A Pines, A %A Francis, MB %B Chemical Communications %8 12/2016 %G eng %R 10.1039/C6CC09302G %0 Journal Article %J ChemComm %D 2016 %T Rotaxane-mediated suppression and activation of cucurbit[6]uril for molecular detection by 129Xe hyperCEST NMR %A Joel A. Finbloom %A Clancy C. Slack %A Carson J. Bruns %A Keunhong Jeong %A David E. Wemmer %A Alexander Pines %A Matthew B. Francis %B ChemComm %G eng %0 Journal Article %J Bioconjugate Chemistry %D 2016 %T Targeted Molecular Imaging of Cancer Cells using MS2-Based 129Xe NMR %A Keunhong Jeong %A Chawita Netirojjanakul %A Henrik K Munch %A Jinny Sun %A Joel A Finbloom %A David E Wemmer %A Alexander Pines %A Matthew B Francis %B Bioconjugate Chemistry %V 27 %8 07/2016 %G eng %U http://pubs.acs.org/doi/abs/10.1021/acs.bioconjchem.6b00275 %N 8 %& 1796 %R 10.1021/acs.bioconjchem.6b00275 %0 Journal Article %J ChemPhysChem %D 2015 %T Investigation of DOTA‐Metal Chelation Effects on 129Xe Chemical Shift %A Keunhong Jeong %A Clancy C. Slack %A Christophoros C. Vassiliou %A Phuong Dao %A Muller D Gomes %A Daniel J. Kennedy %A Ashley E. Truxal %A Lindsay J Sperling %A Matthew B. Francis %A David E. Wemmer %A Alexander Pines %B ChemPhysChem %G eng %0 Journal Article %J Nature Communications %D 2015 %T Room temperature in situ nuclear spin hyperpolarization from optically pumped nitrogen vacancy centers in diamond %A Jonathan P. King %A Keunhong Jeong %A Christophoros C. Vassiliou %A Chang S. Shin %A Ralph H. Page %A Claudia E. Avalos %A Hai-Jing Wang %A Alexander Pines %B Nature Communications %G eng %0 Journal Article %J Nature Communication %D 2014 %T Optical hyperpolarization and NMR detection of 129Xe on a microfluidic chip %A Jimenez-Martinez, R. %A Kennedy, D. J. %A Rosenbluh, M. %A Donley, E. A. %A Knappe, S. %A Seltzer, S. J. %A Ring, H. %A Bajaj, V.S. %A Kitching, J. %B Nature Communication %V 5 %P 3908 %G eng %R 10.1038/ncomms4908 %0 Journal Article %J Journal of Chemical Physics %D 2010 %T Investigation of antirelaxation coatings for alkali-metal vapor cells using surface science techniques %A Seltzer, S. J. %A Michalak, D. J. %A Donaldson, M. H. %A Balabas, M. V. %A Barber, S. K. %A Bernasek, S. L. %A Bouchiat, M. A. %A Hexemer, A. %A Hibberd, A. M. %A Kimball, D. F. J. %A Jaye, C. %A Karaulanov, T. %A Narducci, F. A. %A Rangwala, S. A. %A Robinson, H. G. %A Shmakov, A. K. %A Voronov, D. L. %A Yashchuk, V. V. %A Pines, A. %A Budker, D. %K SPECTROSCOPY %X

Many technologies based on cells containing alkali-metal atomic vapor benefit from the use of antirelaxation surface coatings in order to preserve atomic spin polarization. In particular, paraffin has been used for this purpose for several decades and has been demonstrated to allow an atom to experience up to 10 000 collisions with the walls of its container without depolarizing, but the details of its operation remain poorly understood. We apply modern surface and bulk techniques to the study of paraffin coatings in order to characterize the properties that enable the effective preservation of alkali spin polarization. These methods include Fourier transform infrared spectroscopy, differential scanning calorimetry, atomic force microscopy, near-edge x-ray absorption fine structure spectroscopy, and x-ray photoelectron spectroscopy. We also compare the light-induced atomic desorption yields of several different paraffin materials. Experimental results include the determination that crystallinity of the coating material is unnecessary, and the detection of CvC double bonds present within a particular class of effective paraffin coatings. Further study should lead to the development of more robust paraffin antirelaxation coatings, as well as the design and synthesis of new classes of coating materials. (C) 2010 American Institute of Physics. [doi:10.1063/1.3489922]

%B Journal of Chemical Physics %V 133 %P 144703 %8 October 11, 2010 %@ 0021-9606 %G English %U http://link.aip.org/link/doi/10.1063/1.3489922 %N 14 %9 Article %M WOS:000283200400049 %] 144703 %! Investigation of antirelaxation coatings for alkali-metal vapor cells using surface science techniques %& 144703 %R 10.1063/1.3489922 %0 Journal Article %J Review of Scientific Instruments %D 2007 %T Multipole shimming of permanent magnets using harmonic corrector rings %A Jachmann, R. C. %A Trease, D. R. %A Bouchard, L. S. %A Sakellariou, D. %A Martin, R. W. %A Schlueter, R. D. %A Budinger, T. F. %A Pines, A. %K field %X

Shimming systems are required to provide sufficient field homogeneity for high resolution nuclear magnetic resonance (NMR). In certain specialized applications, such as rotating-field NMR and mobile ex situ NMR, permanent magnet-based shimming systems can provide considerable advantages. We present a simple two-dimensional shimming method based on harmonic corrector rings which can provide arbitrary multipole order shimming corrections. Results demonstrate, for example, that quadrupolar order shimming improves the linewidth by up to an order of magnitude. An additional order of magnitude reduction is in principle achievable by utilizing this shimming method for z-gradient correction and higher order xy gradients. (c) 2007 American Institute of Physics.

%B Review of Scientific Instruments %V 78 %8 Mar %@ 0034-6748 %G English %U ://WOS:000245320800056 %N 3 %M WOS:000245320800056 %! Multipole shimming of permanent magnets using harmonic corrector rings %R Doi 10.1063/1.2713438 %0 Journal Article %J Journal of the American Chemical Society %D 2006 %T Diastereomeric Xe chemical shifts in tethered cryptophane cages %A Ruiz, E. J. %A Sears, D. N. %A Pines, A. %A Jameson, C. J. %K chirality %X

Cryptophane cages serve as host molecules to a Xe atom. Functionalization of cryptophane-A has permitted the development of Xe as a biosensor. Synthetic routes used to prepare cryptophanes result in racemic mixtures of the chiral cages. In the preparation of a tethered cryptophane-A cage for biosensor applications, some achiral and chiral substituents such as left-handed amino acids have been used. When the substituent is achiral, the NMR signal of the Xe atom in the functionalized cage in solution is a single isotropic peak, since the Xe shielding tensor components in the R and L cages differ by no more than the signs of the off-diagonal elements. Chiral substituents can split the cage-encapsulated Xe NMR signal into one or more sets of doublets, depending on the number of asymmetric centers in the substituent. We carry out quantum mechanical calculations of Xe nuclear magnetic shielding for the Xe atom at the same strategic position within an L cryptophane-A cage, under the influence of chiral potentials that represent for r or I substituents outside the cage. Calculations of the Xe shielding response in the Lr and LI diastereomeric pairs permit the prediction of the relative order of the Xe chemical shifts in solutions containing the RI and LI diastereomers. Where the substituent itself possesses two chiral centers, comparison of the calculated isotropic shielding responses in the Llr, Lrl, RIl, and Lrr systems, respectively, permits the prediction of the Xe spectrum of diastereomeric systems in solutions containing Llr, RIr, LIl, and RIl systems. Assignment of the peaks observed in the experimental Xe NMR spectra is therefore possible, without having to undertake the difficult synthetic route that produces a single optically pure enantiomer.

%B Journal of the American Chemical Society %V 128 %P 16980-16988 %8 Dec 27 %@ 0002-7863 %G English %U ://WOS:000242941600104 %N 51 %M WOS:000242941600104 %! Diastereomeric Xe chemical shifts in tethered cryptophane cages %R Doi 10.1021/Ja066661z %0 Journal Article %J Magnetic Resonance in Medicine %D 2005 %T High-resolution nuclear magnetic resonance spectroscopy of biological tissues using projected magic angle spinning %A Martin, R. W. %A Jachmann, R. C. %A Sakellariou, D. %A Nielsen, U. G. %A Pines, A. %K field %X

High-resolution NMR spectra of materials subject to anisotropic broadening are usually obtained by rotating the sample about the magic angle, which is 54.7 degrees to the static magnetic field. In projected magic angle spinning (p-MAS), the sample is spun about two angles, neither of which is the magic angle. This provides a method of obtaining isotropic spectra while spinning at shallow angles. The p-MAS experiment may be used in situations where spinning the sample at the magic angle is not possible due to geometric or other constraints, allowing the choice of spinning angle to be determined by factors such as the shape of the sample, rather than by the spin physics. The application of this technique to bovine tissue samples is demonstrated as a proof of principle for future biological or medical applications.

%B Magnetic Resonance in Medicine %V 54 %P 253-257 %8 Aug %@ 0740-3194 %G English %U ://WOS:000230765700001 %N 2 %M WOS:000230765700001 %! High-resolution nuclear magnetic resonance spectroscopy of biological tissues using projected magic angle spinning %R Doi 10.1002/Mrm.20585 %0 Journal Article %J Actualite Chimique %D 2005 %T Xenon NMR as a probe for microporous and mesoporous solids, polymers, liquid crystals, solutions, flames, proteins, imaging %A Bartik, K. %A Choquet, P. %A Constantinesco, A. %A Duhamel, G. %A Fraissard, J. %A Hyacinthe, J. N. %A Jokisaari, J. %A Locci, E. %A Lowery, T. J. %A Luhmer, M. %A Meersmann, T. %A Moudrakovski, I. L. %A Pavlovskaya, G. E. %A Pierce, K. L. %A Pines, A. %A Ripmeester, J. A. %A Telkki, V. V. %A Veeman, W. S. %K silica-gels %X

We present in this paper some examples of the applications of the Nuclear Magnetic Resonance (NMR) of xenon used as a probe in the study of different chemical environments: determination of the porosity of micro-and mesoporous solids, evaluation of the concentrations and sizes of amorphous domains in solid polymers, characterization of liquid crystals, study of combustion processes at high temperature, determination of the structure and dynamics of organic systems and proteins in solution, assessment of cerebral blood flow.

%B Actualite Chimique %P 16-34 %8 Jun %@ 0151-9093 %G English %U ://WOS:000230991500005 %M WOS:000230991500005 %! Xenon NMR as a probe for microporous and mesoporous solids, polymers, liquid crystals, solutions, flames, proteins, imaging %0 Journal Article %J Solid State Nuclear Magnetic Resonance %D 2002 %T Investigations of low-amplitude radio frequency pulses at and away from rotary resonance conditions for I=5/2 Nuclei %A Logan, J. W. %A Urban, J. T. %A Walls, J. D. %A Lim, K. H. %A Jerschow, A. %A Pines, A. %K solid-state %X

Additional experimental evidence of rotary resonance effects for multiple-quantum coherence conversion in a spin-5/2 system is presented. Two-dimensional plots of the relative efficiency of MQ excitation and conversion are given as a function of radio frequency (rf) amplitude and pulse width. Data are presented for the excitation of five-quantum coherence (5QC), as well as for 5QC to three-quantum coherence (3QC) conversion, 5QC to 1QC (the central transition coherence) conversion, and 3QC to 1 QC conversion. A two-fold increase in the signal-to-noise ratio is achieved by substituting low amplitude rf pulses in place of hard rf pulses for 5QC excitation and 5QC to 3QC conversion in a mixed multiple-quantum magic angle spinning (MAS) (MMQMAS) experiment. The anisotropic line shape for the low-amplitude rf pulse version of the MMQMAS experiment was observed to be distorted from the MAS line shape. The cause and implications of the distortion are discussed. (C) 2002 Elsevier Science (USA).

%B Solid State Nuclear Magnetic Resonance %V 22 %P 97-109 %8 Sep-Nov %@ 0926-2040 %G English %U ://WOS:000179154400003 %N 2-3 %M WOS:000179154400003 %! Investigations of low-amplitude radio frequency pulses at and away from rotary resonance conditions for I=5/2 Nuclei %R Doi 10.1006/Snmr.2002.0084 %0 Journal Article %J Journal of Chemical Physics %D 2002 %T Theoretical investigations of I=5/2 quadrupolar spin dynamics in the sudden-passage regime %A Walls, J. D. %A Lim, K. H. %A Logan, J. W. %A Urban, J. T. %A Jerschow, A. %A Pines, A. %K SPECTROSCOPY %X

The theoretical approach utilizing bimodal Floquet theory in the quadrupolar/central-transition interaction frame, presented in an earlier article [J. D. Walls, K. H. Lim, and A. Pines, J. Chem. Phys. 116, 79 (2002)], is extended to describe the more complicated spin dynamics of I=5/2 spin systems. Rotary resonance effects occur when the strength of the radio-frequency irradiation, omega(1), matches the sample spinning speed, omega(r), at the conditions omega(1) = 2/3nomega(r) (n integral). At these conditions, conversions of both triple-quantum and five-quantum coherences to central-quantum coherence are observed. Between rotary resonance conditions [ 2n/3omega(r)<ω(1)<[2(n+1)]/3ω(r)], five-quantum as well as triple-quantum coherences can be created from equilibrium z-magnetization via a nutation mechanism. In addition, effective transfer between five-quantum and triple-quantum coherences also is observed in between rotary resonance conditions. These effects have been investigated theoretically and verified by both numerical calculations and experimental results. (C) 2002 American Institute of Physics.

%B Journal of Chemical Physics %V 117 %P 518-532 %8 Jul 8 %@ 0021-9606 %G English %U ://WOS:000176424800003 %N 2 %M WOS:000176424800003 %! Theoretical investigations of I=5/2 quadrupolar spin dynamics in the sudden-passage regime %R Doi 10.1063/1.1483256 %0 Journal Article %J Journal of Magnetic Resonance %D 2001 %T High-resolution NMR of quadrupolar nuclei using mixed multiple-quantum coherences %A Jerschow, A. %A Logan, J. W. %A Pines, A. %K pulses %X

A multiple-quantum magic angle spinning (MQMAS) NMR experiment of quadrupolar nuclei is demonstrated, which uses two different multiple quantum coherences in tl to refocus the quadrupolar broadening. This experiment has the potential of achieving improved resolution over current techniques. (C) 2001 Academic Press.

%B Journal of Magnetic Resonance %V 149 %P 268-270 %8 Apr %@ 1090-7807 %G English %U ://WOS:000168628200013 %N 2 %M WOS:000168628200013 %! High-resolution NMR of quadrupolar nuclei using mixed multiple-quantum coherences %R Doi 10.1006/Jmre.2001.2303 %0 Journal Article %J Journal of Chemical Physics %D 1997 %T Geometric dephasing in zero-field magnetic resonance %A Jones, J. A. %A Pines, A. %K xenon %X

Geometric phases acquired randomly can give rise to coherence dephasing in nuclear spin systems, equivalent to spin relaxation. We calculate the form and extent of this geometric dephasing in a number of model systems involving the motion of Xe-131 nuclei in shaped containers. The dephasing is calculated in two ways: first, using an analytical treatment of the diffusive motion of individual nuclei, and second, using ensemble averaged propagators. The effects of applying additional magnetic fields to these systems are discussed briefly. (C) 1997 American Institute of Physics.

%B Journal of Chemical Physics %V 106 %P 3007-3016 %8 Feb 22 %@ 0021-9606 %G English %U ://WOS:A1997WH84300003 %N 8 %M WOS:A1997WH84300003 %! Geometric dephasing in zero-field magnetic resonance %R Doi 10.1063/1.473046 %0 Book Section %B Peptides: Chemistry, Structure and Biology %D 1996 %T Synthetic Peptides Model α - Helix - β - Sheet Conformational Changes in the Prion Protien %A Baldwin, M.A. %A Zhang, H. %A Bekker, T. %A Zhou, S. %A Nguyen, J. %A Kolbert, A.C. %A Heller, J. %A James, T.L. %A Wemmer, D.E. %A Pines, A. %A Cohen, F.E. %A Prusiner, S.B. %E Hidges, Pravin T.P Kaumaya and Robert S. %B Peptides: Chemistry, Structure and Biology %I Mayflower Scientific Ltd. %P 468-470 %G eng %! Synthetic Peptides Model α - Helix - β - Sheet Conformational Changes in the Prion Protien %0 Journal Article %J Chemical Physics Letters %D 1995 %T Berry dephasing due to diffusion in nuclear quadrupole resonance %A Jones, J. A. %A Pines, A. %K nmr %X

Berry's phase can give rise to coherence dephasing in optically detected nuclear quadrupole resonance of gaseous Xe-131. Diffusion of xenon atoms around a toroidal container should cause incoherent acquisition of Berry's phase, with consequent loss of phase coherence between atoms. This leads to signal loss which is equivalent to spin relaxation. The rate of dephasing is calculated by two different methods: first, using an exact treatment of diffusion, and secondly, using average propagators. Berry dephasing is predicted to be an important relaxation mechanism in this system.

%B Chemical Physics Letters %V 247 %P 215-220 %8 Dec 22 %@ 0009-2614 %G English %U ://WOS:A1995TL67100004 %N 3 %M WOS:A1995TL67100004 %! Berry dephasing due to diffusion in nuclear quadrupole resonance %R Doi 10.1016/0009-2614(95)01218-8 %0 Journal Article %J Zeolites and Related Microporous Materials: State of the Art 1994 %D 1994 %T 2-Dimensional Xe-129 Exchange Nmr Measurements of Xenon Dynamics in Na-a Zeolite %A Janicke, M. %A Chmelka, B. F. %A Larsen, R. G. %A Shore, J. %A Schmidt-Rohr, K. %A Emsley, L. %A Long, H. %A Pines, A. %K cavities %X Two-dimensional (2D) exchange NMR is a powerful tool for measuring the dynamics and energetics of adsorbed xenon atoms undergoing slow exchange between the alpha-cages of Na-A zeolite. In this proceedings, we present recently published results, as well as additional discussion and data obtained, using 2D Xe-129 NMR to determine rate coefficients for intercage xenon hopping and to correlate them with adsorption and activation energies. Variable-temperature experiments establish the activation energy for hopping between alpha-cages to be 60+/-10 kJ/mol. The dependence of these kinetic and thermodynamic quantities on xenon occupancy of the alpha-cages reflects the importance of intracage interactions on the behavior of the adsorbed guest molecules. %B Zeolites and Related Microporous Materials: State of the Art 1994 %V 84 %P 519-526 %@ 0167-2991 %G English %U ://WOS:A1994BD02E00063 %M WOS:A1994BD02E00063 %! 2-Dimensional Xe-129 Exchange Nmr Measurements of Xenon Dynamics in Na-a Zeolite %0 Journal Article %J Chemical Physics Letters %D 1993 %T Nmr-Study of Xenon Dynamics and Energetics in Na-a Zeolite %A Larsen, R. G. %A Shore, J. %A Schmidt-Rohr, K. %A Emsley, L. %A Long, H. %A Pines, A. %A Janicke, M. %A Chmelka, B. F. %K xe %X

For xenon atoms adsorbed in Na-A zeolite, electronic interactions cause shifts in NMR frequencies, resulting in a spectrum with discrete peaks from xenon atoms in cages with different xenon occupancies. Using two-dimensional exchange NMR, it is possible to determine the microscopic rates of intercage motion and to relate them to the adsorption and activation energies of the xenon atoms. The dependence of the adsorption energies on xenon cage occupancy reflects the importance of the intercage interactions and is directly related to the cage occupancy distribution. Variable temperature measurements yield an activation energy of about 60 kJ/mol for the transfer of a xenon from one cage to another.

%B Chemical Physics Letters %V 214 %P 220-226 %8 Oct 29 %@ 0009-2614 %G English %U ://WOS:A1993MD61400015 %N 2 %M WOS:A1993MD61400015 %! Nmr-Study of Xenon Dynamics and Energetics in Na-a Zeolite %R Doi 10.1016/0009-2614(93)90085-F %0 Journal Article %J Catalysis Letters %D 1992 %T Adsorption Effects in Aluminophosphate Molecular-Sieves Studied by Al-27 Double-Rotation Nmr %A Jelinek, R. %A Chmelka, B. F. %A Wu, Y. %A Davis, M. E. %A Ulan, J. G. %A Gronsky, R. %A Pines, A. %K alpo4-8 %X

Al-27 double rotation NMR (DOR) spectroscopy is used to investigate structural changes in the framework of several aluminophosphate molecular sieves upon adsorption of water. The shapes, widths, and positions of the spectral lines yield information on the aluminum environments, adsorption sites, and degree of structural disorder undergone upon water adsorption.

%B Catalysis Letters %V 15 %P 65-73 %@ 1011-372X %G English %U ://WOS:A1992JJ25900008 %N 1-2 %M WOS:A1992JJ25900008 %! Adsorption Effects in Aluminophosphate Molecular-Sieves Studied by Al-27 Double-Rotation Nmr %R Doi 10.1007/Bf00770899 %0 Journal Article %J Solid State Nuclear Magnetic Resonance %D 1992 %T Solid-state Al-27 NMR studies of aluminophosphate molecular sieves %A Rocha, J. %A Klinowski, J. %A Barrie, P. J. %A Jelinek, R. %A Pines, A. %K double-rotation %X Solid-state Al-27 NMR spectra of several aluminophosphate molecular sieves have been recorded with conventional magic-angle spinning (MAS), double-rotation (DOR) and quadrupole nutation with fast MAS. Enhanced resolution was obtained in the quadrupole nutation experiment at certain radiofrequency pulse strengths. This extra resolution can be comparable to that attainable using DOR, and does not introduce spinning sidebands. %B Solid State Nuclear Magnetic Resonance %V 1 %P 217-225 %8 Nov %@ 0926-2040 %G English %U ://WOS:000208537300007 %N 4 %M WOS:000208537300007 %! Solid-state Al-27 NMR studies of aluminophosphate molecular sieves %0 Journal Article %J Nanotechnology %D 1992 %T A study of nanostructure assemblies and guest-host interactions in sodium zeolite-Y using Na-23 double rotation NMR %A Jelinek, R. %A Pines, A. %A Ozkar, S. %A Ozin, G.A. %B Nanotechnology %P 182-186 %G eng %N 2 %! A study of nanostructure assemblies and guest-host interactions in sodium zeolite-Y using Na-23 double rotation NMR %0 Conference Paper %D 1991 %T Framework ordering in aluminophosphate molecular sieves studied by (27)Al double rotation NMR %A Chmelka, B.F. %A Wu, Y. %A Jelinek, R. %A Davis, M.E. %A Pines, A. %E P.A. Jacobs, N.I. Jaeger, L. Kubelkova, and B. Wichterlov %I Elsevier %V 69 %P 435-442 %8 1991 %G eng %0 Journal Article %J Journal of the American Chemical Society %D 1991 %T Study of the Aluminophosphates Alpo4-21 and Alpo4-25 by Al-27 Double-Rotation Nmr %A Jelinek, R. %A Chmelka, B. F. %A Wu, Y. %A Grandinetti, P. J. %A Pines, A. %A Barrie, P. J. %A Klinowski, J. %K nuclei %X

Aluminum-27 double-rotation NMR in a magnetic field of 11.7 T distinguishes the extremely distorted five-coordinated aluminum sites in the molecular sieve precursor ALPO4(-21). Upon calcination, ALPO4(-21) transforms to ALPO4(-25), which has two tetrahedral aluminum sites with similar isotropic chemical shifts that cannot be resolved in an 11.7 T field. The two tetrahedral environments, however, have a different quadrupole coupling constants and are distinguished by double rotation at 4.2 T field. The quadrupole coupling constants obtained for these sites indicates that the tetrahedral aluminum environments are less distorted in the hydrated material.

%B Journal of the American Chemical Society %V 113 %P 4097-4101 %8 May 22 %@ 0002-7863 %G English %U ://WOS:A1991FN00500007 %N 11 %M WOS:A1991FN00500007 %! Study of the Aluminophosphates Alpo4-21 and Alpo4-25 by Al-27 Double-Rotation Nmr %R Doi 10.1021/Ja00011a007 %0 Journal Article %J Nature %D 1990 %T High-Resolution Al-27 Nmr-Spectroscopy of the Aluminophosphate Molecular-Sieve Vpi-5 %A Wu, Y. %A Chmelka, B. F. %A Pines, A. %A Davis, M. E. %A Grobet, P. J. %A Jacobs, P. A. %B Nature %V 346 %P 550-552 %8 Aug 9 %@ 0028-0836 %G English %U ://WOS:A1990DT67900067 %N 6284 %M WOS:A1990DT67900067 %! High-Resolution Al-27 Nmr-Spectroscopy of the Aluminophosphate Molecular-Sieve Vpi-5 %R Doi 10.1038/346550a0 %0 Journal Article %J Chemical Physics Letters %D 1989 %T Suppression of the Zero Frequency Peak in Zero-Field Nmr %A Jarvie, T. P. %A Takegoshi, K. %A Suter, D. %A Pines, A. %A Zax, D. B. %B Chemical Physics Letters %V 158 %P 325-328 %8 Jun 9 %@ 0009-2614 %G English %U ://WOS:A1989AB50300029 %N 3-4 %M WOS:A1989AB50300029 %! Suppression of the Zero Frequency Peak in Zero-Field Nmr %R Doi 10.1016/0009-2614(89)87345-2 %0 Journal Article %J Journal of Physical Chemistry %D 1987 %T Effect of Correlated Proton Jumps on the Zero-Field Nmr-Spectrum of Solid P-Toluic Acid %A Jarvie, T. P. %A Thayer, A. M. %A Millar, J. M. %A Pines, A. %B Journal of Physical Chemistry %V 91 %P 2240-2242 %8 Apr 23 %@ 0022-3654 %G English %U ://WOS:A1987H070500006 %N 9 %M WOS:A1987H070500006 %! Effect of Correlated Proton Jumps on the Zero-Field Nmr-Spectrum of Solid P-Toluic Acid %R Doi 10.1021/J100293a006 %0 Journal Article %J Physical Review Letters %D 1987 %T Observation of Spin Diffusion in Zero-Field Magnetic-Resonance %A Suter, D. %A Jarvie, T. P. %A Sun, B. %A Pines, A. %B Physical Review Letters %V 59 %P 106-108 %8 Jul 6 %@ 0031-9007 %G English %U ://WOS:A1987H961300028 %N 1 %M WOS:A1987H961300028 %! Observation of Spin Diffusion in Zero-Field Magnetic-Resonance %R Doi 10.1103/Physrevlett.59.106 %0 Journal Article %J Journal of Chemical Physics %D 1987 %T Theory of Line-Shapes for Zero-Field Nmr in the Presence of Molecular-Motion %A Meier, P. %A Kothe, G. %A Jonsen, P. %A Trecoske, M. %A Pines, A. %B Journal of Chemical Physics %V 87 %P 6867-6876 %8 Dec 15 %@ 0021-9606 %G English %U ://WOS:A1987L166100011 %N 12 %M WOS:A1987L166100011 %! Theory of Line-Shapes for Zero-Field Nmr in the Presence of Molecular-Motion %R Doi 10.1063/1.453381 %0 Journal Article %J Journal of Chemical Physics %D 1986 %T Theory of Chemical-Exchange in Zero-Field Nmr - 2-Site Flips %A Jonsen, P. %A Luzar, M. %A Pines, A. %A Mehring, M. %B Journal of Chemical Physics %V 85 %P 4873-4880 %8 Nov 1 %@ 0021-9606 %G English %U ://WOS:A1986E517600014 %N 9 %M WOS:A1986E517600014 %! Theory of Chemical-Exchange in Zero-Field Nmr - 2-Site Flips %R Doi 10.1063/1.451722 %0 Journal Article %J Journal of Physical Chemistry %D 1986 %T Zero-Field Nuclear-Magnetic-Resonance of a Nematic Liquid-Crystal %A Thayer, A. M. %A Millar, J. M. %A Luzar, M. %A Jarvie, T. P. %A Pines, A. %B Journal of Physical Chemistry %V 90 %P 1577-1581 %8 Apr 10 %@ 0022-3654 %G English %U ://WOS:A1986A860900024 %N 8 %M WOS:A1986A860900024 %! Zero-Field Nuclear-Magnetic-Resonance of a Nematic Liquid-Crystal %R Doi 10.1021/J100399a024