HSQMBC-COSY: Measurement of the sign and the magnitude of long-range proton-carbon coupling constants

“Efficient measurement of the sign and the magnitude of long-range proton-carbon coupling constants from a spin-state-selective HSQMBC-COSY experiment”, by Josep Saurí and Teodor Parella; Magn. Reson. Chem. 2012, 50, 717-721. DOI:10.1002/mrc.3867

A spin-state-selective HSQMBC-COSY experiment is proposed to measure the sign and  the magnitude of long-range proton-carbon coupling constants (nJ(CH); n>1) either for protonated and for non-protonated carbons in small molecules. The simple substitution of the selective 180º 1H pulse in the original selHSQMBC pulse scheme by a hard one allows the simultaneous evolution of both proton-proton and proton-carbon coupling constants during the refocusing period and facilitates a final COSY transfer between coupled protons. The successful implementation of the IPAP principle lead to separate mixed-phase α/β cross-peaks from which nJ(CH) can be easily measured by analysing their relative frequency displacements in the detected dimension.

 Pulse Program Code for Bruker: selHSQMBC-COSY

© 2012, Josep. All rights reserved by the author(s) and Universitat Autonoma de Barcelona except for texts and images already copyrighted by third parties (e.g. journal publishers) and used here under the fair use provision.