Tag Archives: PMMA_gels

Discrimination of stereoisomers with RDCs

“Structural discrimination from in-situ measurement of 1DCH and 2DHH RDCs” by Núria Marcó,  R. R. Gil and Teodor Parella. Magnetic Resonance in Chemistry 2017, DOI: 10.1002/mrc.4575

A fast RDC-assisted strategy involving the simultaneous determination of scalar and total coupling constants from a single 1JCH/2JHH-resolved NMR spectrum is reported. It is shown that the concerted use of the directly measured 1DCH (for all CHn multiplicities) and 2DHH residual dipolar couplings allows an on-the-fly assignment of diastereotopic CH2 protons, as well as of an efficient discrimination between all eight possible diastereoisomeric structures of strychnine, which contains six stereocenters.

Pulse Programs Code for Bruker:

Data set Example:

Extraction of 1JCH for all carbon multiplicities.

“Perfect 1JCH-resolved HSQC: Efficient measurement of one-bond proton-carbon coupling constants along the indirect dimension” by Núria Marcó, A.A. Souza,  Pau Nolis, R. R. Gil and Teodor ParellaJournal of Magnetic resonance 2017, 276, 37-42. DOI: 10.1016/j.jmr.2017.01.002

A versatile 1JCH-resolved HSQC pulse scheme for the speedy, accurate and automated determination of one-bond proton-carbon coupling constants is reported. The implementation of a perfectBIRD element allows a straightforward measurement from the clean doublets obtained along the highly resolved F1 dimension, even for each individual 1JCHa and 1JCHb in diastereotopic HaCHb methylene groups. Real-time homodecoupling during acquisition and other alternatives to minimize accidental signal overlapping in overcrowded spectra are also discussed.

Pulse Programs Code for Bruker:

Data set Example:

RDC measurements and application

joceah_v081i019.inddApplication to the structural discrimination of small molecules containing multiple stereocenters. One-Shot determination of residual dipolar couplings.
Castañar, L.; Garcia, M.; Hellemann, E.; Nolis, P.; Gil, R.; Parella, T.


A novel approach for the fast and efficient structural discrimination of molecules containing multiple stereochemical centers is described. A robust Jresolved HSQC experiment affording highly resolved 1JCH/1TCHsplittings along the indirect dimension and homodecoupled 1H signals in the detected dimension is proposed. The experiment enables in-situ distinction of both isotropic and anisotropic components of molecules dissolved incompressed PMMA gels, allowing a rapid and direct one-shot determination of accurate residual dipolar coupling constants from a single NMR spectrum