Nuclear Magnetic Resonance spectroscopy is based on the idea that some nuclei can behave as little magnetic bars (I spin number ≠ 0). In the presence of a magnetic field (B0) the nuclear spins feel a small torque for or against the B0 axis, which results in a net magnetization along the B0 direction. Benchtop NMR 1-855-NMREADY (667-3239) toll-free in the US and Canada.

Distortionless Enhancement by Polarization Transfer (DEPT) is a double resonance pulse program that transfers polarization from an excited nucleus to another – most commonly 1H → 13C. This results in a sensitivity enhancement relative to the standard decoupled 1D carbon spectra (13C), which benefits only from the small Nuclear Overhauser Effect (NOE) enhancements.

Nuclear Magnetic Resonance spectroscopy is based on the idea that some nuclei can behave as little magnetic bars (I spin number ≠ 0). In the presence of a magnetic field (B0) the nuclear spins feel a small torque for or against the B0 axis, which results in a net magnetization along the B0 direction. Benchtop NMR 1-855-NMREADY (667-3239) toll-free in the US and Canada.

Distortionless Enhancement by Polarization Transfer (DEPT) is a double resonance pulse program that transfers polarization from an excited nucleus to another – most commonly 1H → 13C. This results in a sensitivity enhancement relative to the standard decoupled 1D carbon spectra (13C), which benefits only from the small Nuclear Overhauser Effect (NOE) enhancements.

As Valentine’s Day approaches, I decided to analyze the 1H nuclear magnetic resonance (NMR) spectrum of the main aromatic component of roses, carnations, violets, lilies and chrysanthemums, which were b-damascenone, eugenol, b-ionone, linalool and a-pinene, respectively.

In NMR, the net magnetization is detected in the xy plane, giving rise to the FID (Free Induction Decay). The process by which the magnetization in the xy plane decays away, over time, to its equilibrium value of zero, is known as T2 relaxation, transversal relaxation, relaxation on the xy plane, or spin-spin relaxation.

2D NMR experiments provide chemists with evidence to clarify and confirm resonance assignment.  Nowadays every organic chemist uses these experiments called COSY, HMBC and HSQC as routine analytics. Basically, with 2D experiments you correlate some kind of information between two 1D spectra. If we correlate two 1D spectra of the same nucleus we are dealing with homonuclear 2D NMR experiments. The most famous representative of this group is the COSY experiment (find theory here and application here).

NMR spectroscopy is by far the most useful characterization technique in organic chemistry, especially if you have to elucidate the structure or configuration of your products. Arguably, 2D experiments such as COSY, HSQC, and HMBC have simplified this task tremendously. In this post I wanted to highlight the COSY of α-humulene. Read more.

Distortionless Enhancement by Polarization Transfer (DEPT) is a double resonance pulse program that transfers polarization from an excited nucleus to another – most commonly 1H → 13C. This results in a sensitivity enhancement relative to the standard decoupled 1D carbon spectra (13C), which benefits only from the small Nuclear Overhauser Effect (NOE) enhancements.