Code: MOB	Time Slot/Poster Number: 10:45-11:10	Session: Liquids I: Small Organic Molecules
Protons and Nitrogen and Carbon et alia
Eriks Kupce1; Ray Freeman2
1Varian, Inc., Oxford, United Kingdom; 2Jesus College, Cambridge University, Cambridge, UK
Abstract
A recent instrumental innovation permits the simultaneous acquisition of signals from several nuclear species, for example 1H, 13C, 15N, 19F or 31P, using multiple receivers. The separate development of a cryogenically-cooled probe improves the sensitivity of 13C detection by an order of magnitude, rendering the INADEQUATE experiment a more practical proposition for establishing the carbon framework of an organic molecule. Together these two techniques have allowed three important NMR pulse sequences, INADEQUATE, HSQC and HMBC, to be combined into a single entity to provide reliable structural information in a single shot. We call this scheme PANACEA, sure remedy for small molecules.

Code: MOB	Time Slot/Poster Number: 11:10-11:25	Session: Liquids I: Small Organic Molecules
Gradient-only Controlled Folding of Ultrafast 2D NMR spectra
Patrick Giraudeau; Serge Akoka
Université de Nantes, Nantes, France
Abstract
Ultrafast 2D NMR allows the acquisition of a 2D spectrum in a single scan, however it fails in covering large spectral ranges due to gradient amplitude limitations. Various approaches relying on selective pulses have been proposed to bypass this limitation, however, they require implementing selective pulses associated with a number of drawbacks. We propose a simple method capable of dividing by a factor of 2 the demand on gradient amplitudes, by implementing additional gradients in the sequence on each side of the mixing period, and no selective pulses. The effective spectral width is doubled with no need to increase the detection gradient amplitudes. Results obtained on different compounds and pulse sequences will be presented, highlighting the efficiency of our method.

Code: MOB	Time Slot/Poster Number: 11:25-11:50	Session: Liquids I: Small Organic Molecules
Recent advances in the use of RDCs for organic structure determination
Christina M. Thiele
Technische Universitat Darmstadt, Darmstadt, Germany
Abstract
Our recent developments in the use of Residual Dipolar Couplings for organic structure determination will be presented. Especially the proper treatment of conformational averaging will be discussed and the use of local alignment tensors for the determination of relative configurations will be shown. With these methods in hand we were also able to apply RDCs to the determination of solution conformations and dynamics of catalytically active species.

Code: MOB	Time Slot/Poster Number: 11:50-12:05	Session: Liquids I: Small Organic Molecules
Using a Blind Source Separation Method to extract overlaped multiplets in selective NMR spectra
Clark D. Ridge1; Federico Del Rio-Portilla2; Yuanchang Sun1; A. J. Shaka1; Jack Xin1
1University of California at Irvine, Irvine, CA; 2UNAM, Mexico City, Mexico
Abstract
Using a doubly selective heteronuclear Hartman-Hahn transfer experiment the multiplets of 13C carbonyl labeled peracetylated maltitol are mostly separated in individual selective proton spectra. However, there are some multiplets that still overlap. These multiplets can be separated by seeing this as an instance of the blind source separation (BSS) problem. By moving the transmitter in the carbon or proton dimension the overlapping multiplets can be scaled by different factors. What those factors are is difficult to calculate but for the BSS problem it doesn't matter. Using a modified method of solving the BSS problem can separate the multiplets and other NMR signals that can be modeled as a linear mixture.

Code: MOB	Time Slot/Poster Number: 12:05-12:30	Session: Liquids I: Small Organic Molecules
Low-pass J filters fail in case of strong coupling and how to purge such artifacts in HMBC, plus 3D H2BC
Ole W. Sørensen
DTU Chemistry, Kgs. Lyngby, Denmark
Abstract
Higher order low-pass J filters are usually quite effective in suppressing one-bond correlations in HMBC-type spectra even for wide J ranges, but in case of strong coupling they are often inadequate and not better than a first order filter. Clean HMBC is a general remedy for this. H2BC was introduced a few years ago to handle the problem of two- and three-bond correlations not being distinguishable in HMBC spectra and also to provide correlations when two-bond J(CH) vanishes. Without extending the duration of the pulse sequence, a third dimension can be added to H2BC, so that 3D H2BC spectra contain both heteronuclear one- and two-bond correlations in addition to COSY information.