In an HMQC spectrum, a 13 C spectrum is displayed on one axis and a 1 H spectrum is displayed on the other axis. Cross-peaks show which proton is attached to which carbon. COSY spectra show 3-bond coupling (from H-C-C-H), whereas HMQC shows a 1-bond coupling (just C-H). Take a look at n-hexylbenzene.

2024年11月12日 · Draw the HMBC correlations as double-headed arrows on your structure. HMBC to Distinguish Isomers. The ability to connect spin systems is quite powerful especially when looking at isomers. When looking at the 1 H NMR and 13 C NMR of this compound, one can propose three spin systems.

HSQC and HMBC The HSQC (Heteronuclear Single Quantum Coherence) experiment is used to determine proton-carbon single bond correlations, where the protons lie along the observed F2 (X) axis and the carbons are along the F1 (Y) axis.

Download scientific diagram | Key HMBC (arrows) and COSY (bold lines) correlations of 1-8. from publication: Halogenated and Nonhalogenated Metabolites from the Marine-Alga-Endophytic Fungus ...

Learn about common setup and use issues with HMBC. Combine 1D and 2D spectra to provide assignments, and in this session utilize the capabilities provided by MNova. HMBC is both similar and different from HSQC in setup and use. Key points are: HMBC experiments are not as sensitive as HSQC: a common rule-of-thumb is HMBC takes 4 as long as HSQC.

Learn about common setup and use issues with HMBC. Combine 1D and 2D spectra to provide assignments, and how to publish NMR data using MNova. HMBC is both similar and different from HSQC in setup and use. Key points are: HMBC experiments are not as sensitive as HSQC: a common rule-of-thumb is HMBC takes 4 as long as HSQC.

Selected HMBC (arrow) correlations of compounds 1, 2 and 7. [...] Quorum sensing (QS) plays an important role in the production of virulence factors and pathogenicity in pathogenic bacteria and...

Key HMBC (arrow H→C) and COSY (bond) spin coupling systems for compound 1. [...] Six new (3Z,5E)-11,20-epoxybriara-3,5-dien-7,18-olide diterpenoids, gemmacolides N-S (1-6), were isolated together...

After a short introduction into the basic theory, this article will provide a comprehensive and pedagogical description of the classical HMBC pulse sequences, with the aid of product operator formalism.

Just as COSY spectra show which protons are coupled to each other, HMBC (and the related HMQC) give information about the relative relationships between protons and carbons in a structure. In an HMQC spectrum, a 13 C spectrum is displayed on one axis and a 1 H spectrum is displayed on the other axis.