Abstract
Abstract Several inverse-detected one-dimensional methods for measurement of long-range heteronuclear coupling constants are proposed. A double-INEPT-type polarization transfer is used in these sequences. An initial transfer via one-bond couplings is followed by modulation of the single-quantum carbon magnetization by long-range heteronuclear couplings and a final back-transfer of the carbon magnetization to protons. Multiplets in pure antiphase with respect to the heteronuclear long-range couplings and additional in-phase splitting from proton-proton couplings are observed. Selection of a particular isotopomer, the subspectrum of which is coadded constructively during the course of the experiment, is achieved by a combined use of selective pulses and chemical-shift-selective filters, both applied in the 13C or the 1H frequency domains. Modifications are proposed which remove the undesirable effect of one-bond and passive long-range proton-carbon coupling constants. Signal intensities are analyzed theoretically and compared experimentally for various experimental schemes. The methods are illustrated on a peracetylated β-cyclodextrin (Mr = 2016 g/mol). The emphasis is placed on the measurement of interglycosidic heteronuclear long-range couplings, which proved to be useful in the conformational analysis of saccharides.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
