Geoffrey Bodenhausen

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The fine structures of multiplets in 2-dimensional correlation spectra arise from coherence transfer processes that can be rationalized in terms of connectivity diagrams. These can be derived from conventional energy-level diagrams, which in turn reflect the networks of coupled spins. Automated anal. of multiplets in 2-dimensional spectra does not yield the global coupling networks, but merely a set of hypothetical fragments of the networks. The relationship between the fragments and the parent coupling net

Dipolar-coupled spectra of mols. dissolved in liq. cryst. solvents were analyzed by applying pattern recognition procedures to 2-dimensional z-filtered correlation spectra (z-COSY). Transitions that share common common energy levels can be recognized as such by recording spectra with different flip angles. This allows one to obtain a picture of the energy-level diagram without knowledge of the Hamiltonian, although in the current preliminary version of the program, the no. of spins and their symmetry must b

Difficulties are described which are encountered in NMR spectroscopy when attempting to invert simultaneously several multiplets that comprise transitions which share common energy levels. These problems turn out to be due to the undesirable excitation of multiple-quantum coherences. The discussion of these effects is limited to inversion with 2 simultaneous 180 Deg pulses having time-domain envelopes given either by simple rectangular box functions or by so-called G3 Gaussian pulse cascades. [on SciFinder

A novel spin-echo expt. is proposed that uses semiselective Gaussian pulse cascades for refocusing in systems with homonuclear couplings. The expt. allows one to obtain evdience of differential T2 effects due to cross-correlation of proton chem. shift anisotropy and proton-proton dipolar interactions in a small arom. compd. at 9.4 T. The spin-echo expt. was applied to measure transverse relaxation rates for selected multiplets of the cyclic undecapeptide cyclosporin. Possible extensions to multiple-quantum

Adiabatically swept pulses were originally designed for the purpose of broadband spin inversion. Later, unexpected advantages of their utilization were also found in other applications, such as refocusing to excite spin echoes, studies of chemical exchange ...

The application of a computer-assisted structure elucidation expert system, CISOC-SES, leading to the unequivocal 1H, 13C and NOE resonance assignment of betulinic acid, a biol. active triterpenoid with complicated NMR resonances, is described. The procedure consists of peak picking that is independent of background information, systematic interpretation of connectivity information from 2D NMR into bond constraints and resonance assignment based on the proposed structure. De novo structure generation based

The principal components and orientations of the chem. shift anisotropy (CSA) tensors of nearly all 13C carbonyl nuclei in a small protein have been detd. in isotropic soln. by a combination of three complementary cross-correlation measurements. [on SciFinder (R)]

New experiments are described for the determination of very slow diffusion constants by nuclear magnetic resonance (NMR) using long-lived (singlet) states. These experiments are suitable for molecules or conformations featuring a wide range of J-couplings. ...

PROBLEM TO BE SOLVED: To provide an effective and speedy method for decoupling of homonuclear couplings.SOLUTION: This invention concerns a method for high resolution NMR (nuclear magnetic resonance) measurements comprising the application of excitation pu ...

A solid-state 13C NMR spectrum, obtained with cross-polarization and magic-angle sample spinning, and a high-resoln. 13C NMR spectrum of a 0.07 M CHCl3 soln. indicated the presence of a 1:1 cis-trans ratio of the PdCl2(PMe2Ph)2 isomers in the solid-state. In EtOH soln. a 10:1 ratio was obsd. cis- And trans-PdCl2(PMePh2)2 also exhibited a 1:1 molar ratio in the solid state according to 13C NMR data. [on SciFinder (R)]

The indirect detection of 14N spectra via protons in the manner of heteronuclear multiple-quantum correlation (HMQC) allows one to obtain single- (SQ) and double-quantum (DQ) 14N spectra in solids. A comparison of the SQ and DQ line widths as a function of ...

A method for producing hyperpolarized sample material for use in magnetic resonance investigations, with a) preparing a target material, containing high gamma nuclei with a short T1, - a polarizing agent with a broad EPR line, and low gamma nuclei with a l ...

In most applications of dissolution-DNP, the polarization of nuclei with low gyromagnetic ratios such as C-13 is enhanced directly by irradiating the ESR transitions of radicals with narrow ESR lines such as Trityl at low temperatures T = 1.2 K in polarizing fields B-0 C-13) in excess of 70% within 20 min. A

A heteronuclear double-resonance (HDR) method based on MLEV-32 or WALTZ-32 pulse sequences has been designed for the investigation of relaxation of heteronuclear multiple-quantum (MQ) coherences. The theoretical analysis of this technique uses average Hami ...

The proton and 31P NMR spectra of 2',3'-cyclic uridine monophosphate have been correlated by means of heteronuclear two-dimensional NMR. The spectra depend on the flip angle of one of the rf pulses. This is in contrast to previously reported applications where the 31P nucleus was coupled to a single proton only. For flip angles other than 90 Deg the spectra cannot be readily related to conventional proton spectra and the conformational information is obscured. The resulting multiplets can be analyzed by rou

In NMR pulse experiments transverse magnetization is excited by irradiating the nuclear spin system with a two pulse sequence of a first RF chirp pulse and a second RF chirp pulse, generated after a defocusing time interval tau . The pulse duration of the second chirp pulse is half the duration of the first pulse, and the amplitude of the second chirp pulse is approximately three times the amplitude of the first chirp pulse. The first pulse being a 90 DEG -pulse, the second pulse being a 180 DEG -pulse, a r

A method for producing a hyperpolarized sample for use in a magnetic resonance investigation, with the following steps: a) providing a solid sample (50), containing long T1 nuclei and short T1 nuclei in the same molecules (51) b) hyperpolarizing the short ...

Vitamin C for longer lifetimes: N-oxide radicals that are widely used for dynamic nuclear polarization can be reduced by scavengers such as sodium ascorbate (vitamin C) during the dissolution process, thus diminishing losses of polarization during the tran ...

In isotopically labeled macromols., it is possible to excite the signal of a selected proton by shuttling magnetization back and forth between the chosen proton and a heteronucleus such as 13C or 15N, using two-way doubly selective heteronuclear cross-polarization. Selective excitation of a chosen proton can be followed by homonuclear coherence transfer to identify side-chain resonances of the corresponding amino acid in proteins. The resulting one-dimensional expts. yield information that can usually only

The cross-correlation spectral d. of chem. shift anisotropy and dipolar interactions in isotropic soln. of Me fomate was measured using a novel NMR technique designed to monitor the appearance of longitudinal 2-spin order during inversion recovery. The results is tentatively interpreted in terms of the orientation of the 13C-1H internuclear vector with respect to the main axes of the 13C chem. shift anisotropy tensor of the carboxyl group. [on SciFinder (R)]

Geoffrey Bodenhausen

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Automated analysis of two-dimensional correlation spectra: assembly of fragments into networks of coupled spins

Toward automated analysis of dipole-coupled NMR spectra of solutes in liquid crystals

Double selective inversion in NMR and multiple quantum effects in coupled spin systems

Measurement of transverse relaxation in coupled spin systems by semi-selective refocusing: evidence for interference of CSA and dipolar relaxation

Cross-correlated relaxation measurements under adiabatic sweeps: determination of local order in proteins

Computer-assisted structure elucidation: application of CISOC-SES to the resonance assignment and structure generation of betulinic acid

Determination of chemical shift anisotropy tensors of carbonyl nuclei in proteins through cross-correlated relaxation in NMR

Measurement of Slow Diffusion Coefficients of Molecules with Arbitrary Scalar Couplings via Long-Lived Spin States

Fourier tickling for homonuclear decoupling in nmr

Solid state carbon-13 NMR spectroscopy: the isomer distribution in the solution and solid phases of PdCl2(PMe2Ph)2

Evidence for Dynamics on a 100 ns Time Scale from Single- and Double-Quantum Nitrogen-14 NMR in Solid Peptides

Method and device for rapid dnp

High field dynamic nuclear polarization at 6.7T: Carbon-13 polarization above 70% within 20min

Preservation of heteronuclear multiple-quantum coherences in NMR by double-resonance irradiation

Elimination of flip-angle effects in two-dimensional NMR spectroscopy. Application to cyclic nucleotides

A method for exciting transverse magnetization in nmr pulse experiments

Method for hyperpolarization transfer in the liquid state

Scavenging Free Radicals To Preserve Enhancement and Extend Relaxation Times in NMR using Dynamic Nuclear Polarization

Excitation of Selected Proton Signals in NMR of Isotopically Labeled Macromolecules

Observation of 2IzSz order in NMR relaxation studies for measuring cross-correlation of chemical shift anisotropy and dipolar interactions