Probing long-range anisotropic interactions - A general and sign-sensitive strategy to measure 1H-1H residual dipolar couplings as a key advance for organic structure determination.

Probing long-range anisotropic interactions - A general and sign-sensitive strategy to measure 1H-1H residual dipolar couplings as a key advance for organic structure determination.
Angew Chem Int Ed Engl. 2020 Jan 16;:
Authors: Sinnaeve D, Ilgen J, Di Pietro ME, Primozic JJ, Schmidts V, Thiele CM, Luy B
Abstract
Residual dipolar couplings (RDCs) are amongst the most powerful NMR parameters for organic structure elucidation. In order to maximize their effectiveness in increasingly complex cases such as flexible compounds, a maximum of RDCs between nuclei sampling a large distribution of orientations is needed, including sign information. For this, the easily accessible one-bond 1 H- 13 C RDCs alone often fall short. Long-range 1 H- 1 H RDCs are both abundant and typically sample highly complementary orientations, but accessing them in a sign-sensitive way has been severely obstructed due to the overflow of 1 H- 1 H couplings. Here, we present a generally applicable strategy that allows the measurement of a large number of 1 H- 1 H RDCs, including the sign, that is based on a combination of an improved PSYCHEDELIC method and a new selective constant-time β-COSY experiment. The potential of 1 H- 1 H RDCs to better determine molecular alignment and to discriminate between enantiomers and diastereomers is demonstrated.
PMID: 31945235 [PubMed - as supplied by publisher]

Source: Angewandte Chemie - January 15, 2020 Category: Chemistry Authors: Sinnaeve D, Ilgen J, Di Pietro ME, Primozic JJ, Schmidts V, Thiele CM, Luy B Tags: Angew Chem Int Ed Engl Source Type: research