Geoffrey Bodenhausen

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Selective proton decoupling was used to remove one of the homonuclear splittings in heteronuclear 2-dimensional NMR. The addnl. effort required to adjust the decoupler frequency to one of the proton shifts is easily offset by the increased simplicity of the spectra. In the expt., continuous weak irradn. is applied at the chem. shift of one of the distant protons which is not directly coupled to the P nuclei. The carrier frequency of both proton pulses and selective irradn. is chosen to be one and the same.

© 2014 John Wiley & Sons, Ltd. We report applications of dynamic nuclear polarization to enhance proton and vanadium-51 polarization of vanadyl sulfate samples dopedwith TOTAPOL undermagic angle spinning conditions. The electron paramagnetic resonance response stemming from the paramagnetic 51V species was monitored as a function of pH, which can be adjusted to improve the enhancement of the proton polarization. By means of cross-polarization from the proton bath, 51V spins could be hyperpolarized. Enhancem

The resoln. in heteronuclear 2-dimensional NMR spectroscopy is affected by coherence transfer echoes. By introducing a delay between the transfer of coherence and the signal observation, the resoln. in the crucial w1 dimension can be enhanced. This procedure removes the symmetry of the multiplet structure, and an addnl. pulse is required to realign the signals in the 2-dimensional spectra. The methods are illustrated by applications to the indirect observation of scalar proton-proton couplings through P-31

This contribution seeks to identify a few factors that have contributed to the success of a thriving discipline, and to identify threats that could put future prospects at risk. Many of these factors are not specific to magnetic resonance, and may also app ...

Line broadening in high-resoln. NMR spectra caused by heteronuclear scalar coupling is described, and various adiabatic frequency-modulated decoupling schemes in high-resoln. NMR spectroscopy are compared. The CHRIP-95 decoupling scheme, which uses a linear frequency-swept pulse for adiabatic inversion of the magnetization, combined with an 80-step phase cycle that is derived from a 5-step phase cycle and a 16-step supercycle, allows on to cover very broad bandwidths with a great tolerance for variation in

If the 90 Deg selective pulses that are normally used for vol. localization are replaced with self-refocusing 270 Deg pulses having a Gaussian time-domain amplitude profile, various pulse sequences can be made shorter, thus reducing the effects of transverse relaxation, flow, or diffusion. The sensitivity advantage is ascertained quant. for some of the commonly used sequences. The vol. of interest defined in these expts. is detd. by the offset dependence (spatial profile) of the conversion of transverse xy

A high throughput method was designed to produce hyperpolarized gases by combining lowtemperature dynamic nuclear polarization with a sublimation procedure. It is illustrated by applications to 129Xe nuclear magnetic resonance in xenon gas, leading to a si ...

Thurber and Tycko recently described a 'bleaching effect' that occurs in magnetic resonance when solid samples that are doped with paramagnetic agents are subjected to rotation by magic angle spinning (MAS) in a static magnetic field with a rotation period ...

The spin echo is the single most important building block in modern NMR spectroscopy, but echo modulation by scalar couplings J can severely complicate its use. We show for the first time that a general but unacknowledged solution to such complications already exists.

A new method for selective excitation in biomol. NMR uses two-fold single-transition cross-polarization between protons and nitrogen-15 or carbon-13 nuclei. Switching the frequencies between the forward and backward transfer steps allows one to select a multiplet pattern that is assocd. with a single pair of spins in a medium-size protein. The efficiency of the transfer benefits from so-called TROSY line-narrowing effects which arise from interference between relaxation mechanisms. [on SciFinder (R)]

In high-resoln. NMR spectra of scalar coupled spins in isotropic phase, it is possible to convert single- into triple-quantum coherences and vice versa by irradiating simultaneously at the frequencies of 3 chem. shifts. A triple resonance condition can be achieved by modulating a radiofrequency carrier by a product of 2 cosinusoidal audiowaves, chosen so that 3 of the 4 sidebands coincide with 3 selected chem. shifts. When used in conjunction with 2-dimensional Fourier transform spectroscopy, it is possible

Small diffusion coeffs. can be measured by using populations of singlet states that have a relaxation time const., Ts, which can be much longer than the longitudinal relaxation time, T1. Spatial information can be encoded with pulsed field gradients in the ...

In NMR spectroscopy in an isotropic phase, coherence can be transferred with a single rf pulse between 2 spins which possess no mutual scalar coupling. Such anomalous coherence processes are assocd. with multiexponential transverse relaxation that can arise, among other mechanisms, from cross-correlation between 2 time-dependent dipolar interactions. [on SciFinder (R)]

(Figure Presented) Chemical shifts of protons can report on metabolic transformations such as the conversion of choline to phosphocholine. To follow such processes in vivo, magnetization can be enhanced by dynamic nuclear polarization (DNP). We have hyperp ...

A new method called selective inversion soft COSY (SIS-COSY) is described. By using this method the coupling between active and passive spins can be detected. The pulse sequence consists of 3 semiselective 270 Deg pulses, which gives a spectrum consisting of 2 pos. and 2 neg. signals. The method is applied to the cis and trans isomers of 2-phenylcyclopropanecarbonic acid Me ester. [on SciFinder (R)]

Cross-correlated relaxation of multiple-quantum coherences in NMR was used to investigate hydrogen bonds in Watson-Crick base pairs, based on the interference between various relaxation mechanisms. [on SciFinder (R)]

In two influential paper, Ernst and coworkers argued that cross-polarization, originally proposed by Hartmann and Hahn, can be very useful in isotropic liqs. to transfer coherence between scalar-coupled nuclei such as protons and carbon-13 (Maudsley, A. A., Muller, L., and Ernst, R. R., 1977; J. Magn. Reson., 28, 463; Muller, L., and Ernst, R. R., 1979, Molec. Phys., 38, 963). Unfortunately, the efficiency of cross-polarization in liqs. tends to be strongly attenuated if the radiofrequency fields are not pe

Different decoupling sequences are tested - using various shaped radio-frequency (RF) pulses - to achieve the longest possible lifetimes of singlet-state populations over the widest possible bandwidths, that is, ranges of offsets and relative chemical shif ...

The peak intensities within the multiplets in a 2-dimensional NOESY expt. with small flip angles reflect the transition probabilities due to dipolar and other relaxation mechanisms. In the initial rate approxn., the relaxation rates (elements of the W matrix) can be extd. directly from individual peak amplitudes. Beyond the linear regime, a comparison of exptl. and simulated spectra allows one to distinguish between different hypotheses regarding assignment, structure and mol. motion. [on SciFinder (R)]

199Hg NMR spectroscopy is used to examine the interaction of the toxic organomercurial ethylmercury phosphate [2235-25-8] with various amino acids. Because of the relative insensitivity of 199Hg and the low concns. of biol. mols., a heteronuclear spin-echo and a 2-dimensional technique involving a double transfer of polarization are used to bypass the concn. limits of direct detection. The chem. shifts of 199Hg cover a wide range (600 ppm for ethylmercury derivs.) and are diagnostic for the identity of the

Geoffrey Bodenhausen

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Double resonance in heteronuclear two-dimensional spectroscopy

Dynamic nuclear polarization enhancement of protons and vanadium-51 in the presence of pH-Dependent vanadyl radicals

Resolution enhancement in heteronuclear two-dimensional spectroscopy of realignment of coherence transfer echoes

A bright future for magnetic resonance

Evaluation of adiabatic frequency-modulated schemes for broadband decoupling in isotropic liquids

Volume-selective NMR spectroscopy with self-refocusing pulses

Hyperpolarizing Gases via Dynamic Nuclear Polarization and Sublimation

Rotation-induced recovery and bleaching in magnetic resonance

Spin echo NMR spectra without J modulation

Highly selective excitation in biomolecular NMR by frequency-switched single-transition cross-polarization

Triple-quantum NMR by selective triple resonance

Slow Diffusion by Singlet State NMR Spectroscopy

Relaxation-allowed transfer of coherence in NMR between spins which are not scalar coupled

Proton NMR of15N-choline metabolites enhanced by dynamic nuclear polarization

Entflechtung überlagernder Multipletts in zweidimensionalen NMR‐Korrelationsspektren durch selektive Inversion der Spins der Kopplungspartner

Hydrogen bonds in RNA base pairs investigated by cross-correlated relaxation of multiple-quantum coherence in NMR

Selective cross-polarization in solution state NMR

Extending the Scope of Singlet-State Spectroscopy

Determination of relaxation pathways in coupled spin systems by two-dimensional NMR exchange spectroscopy with small flip angles

Indirect detection of mercury-199 NMR: adducts of ethylmercury phosphate with amino acids and ribonuclease