Scientific article
English

NMR Characterization of Complex p-Oligophenyl Scaffolds by Means of Aliasing Techniques to Obtain Resolution-Enhanced Two-Dimensional Spectra

Published inHelvetica chimica acta, vol. 87, no. 9, p. 2190-2207
Publication date2004
Abstract

The usefulness of computer-assisted aliasing to secure maximal resolution of signal clusters in 1H- and 13C-NMR spectra (which is essential for structure determination by HMBC 2D NMR spectroscopy) in minimal acquisition time is exemplified by the complete characterization of the two complementary p-octiphenyls 1 and 2 with complex substitution patterns. The need for digital resolution near 1 Hz/pt to dissect the extensive signal clusters in the NMR spectra of these refined oligomers excluded structure determination under routine conditions. High resolution was secured by exploiting the low signal density in the 13C dimension of HMBC spectra by using computer-assisted aliasing to maximize signal density. Based on the observed shifts in DEPT and 1H-decoupled 13C-NMR spectra of 1 and 2, computer-assisted aliasing allowed to reduce the number of required time increments by a factor of 20 to 30 compared to full-width spectra with identical resolution. Without signal-to-noise constraints, this computer-assisted aliasing reduced the acquisition time for high-resolution NMR spectra needed for complete characterization of refined oligomers 1 and 2 by the same factor (e.g., from over a day to about an hour). With resolved signal clusters in fully aliased HSQC and HMBC spectra, unproblematic structure determination of 1 and 2 is demonstrated by unambiguous assignment of all C- and H-atoms. These findings demonstrate that computer-assisted aliasing of the underexploited 13C dimension makes extensive molecular complexity accessible by conventional multidimensional heteronuclear NMR experiments without extraordinary efforts.

Citation (ISO format)
JEANNERAT, Damien et al. NMR Characterization of Complex p-Oligophenyl Scaffolds by Means of Aliasing Techniques to Obtain Resolution-Enhanced Two-Dimensional Spectra. In: Helvetica chimica acta, 2004, vol. 87, n° 9, p. 2190–2207. doi: 10.1002/hlca.200490199
Main files (1)
Article
accessLevelRestricted
Identifiers
Journal ISSN0018-019X
571views
0downloads

Technical informations

Creation21/06/2010 10:28:01
First validation21/06/2010 10:28:01
Update time14/10/2025 06:56:24
Status update14/03/2023 15:46:53
Last indexation02/11/2025 20:15:36
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack