Analytical Instrument Documents

15N NMR is widely used because of the importance of nitrogen in chemistry, materials, biology, environment, etc. However, very low abundance of 15N (<0.4%) results in poor sensitivity and thus makes observation time-consuming. On the other hand, the rest of nitrogen atoms are also NMR sensitive nucleus of 14N. Despite the high abundance of 14N (>99%), it's application is rather limited due to the huge quadrupolar interactions and its spin quantum number I = 1.

JEOL AUTOMAS probe combined with Auto Sample Changer and Auto Tune Unit allows for fully automated solid NMR measurements including sample load/eject, tuning and matching, magic angle spinning frequency control, and temperature control. This enables you to manage efficient data collection as liquid NMR.

We can supply 2.5, 3.2 or 4.0 mm XY-MAS probes suitable for inorganic materials. The XY-MAS probe has two rf channels which enable simultaneous strong rf-field irradiation.

Fluorine and nitrogen containing organic compounds are often found in a variety of fields such as pharmaceutical and material sciences. Such compounds show unique properties based on their conformations and orientations, which are often induced by hydrogen bonds between N-H and F atoms. Therefore, analysis of molecular conformations and inter-molecular interactions are important. Here, we report 14N decoupled 1H-19F HETCOR as an example of hydrogen bonds analysis between N-H and F for fluorinated benzanilide as a demonstration.

No-D NMR (No-Deuterium Proton NMR) technique is a measurement of high resolution 1H NMR spectra without deuterium solvent. It suggests that any reaction mixture or reagent solution are directly available for No-D NMR measurement.

In this article, we will show the accurate measurements of the diffusion coefficients (D) by using room-temperature ionic liquids (RTIL, IL) as examples.

13C NMR spectra provide wide range chemical shift, and it suggests that can easily distinguish each signals. But carbon resolution of 2D spectra such as HSQC and HMBC is worse than 1D 13C spectra due to small data points. In order to analyze a compound with close 13C chemical shifts, a high resolution 2D spectrum is required frequently. In this document, some improvements to distinguish each signals on 13C axis of 2D hetero nuclear experiments are presented.

POMMIE (Phase Osacillations to Maximize Editing) is a 13C experiment that, like the more familiar DEPT experiment, utilizes polarization transfer to enhance the intensities of the 13C signals. However, unlike DEPT, POMMIE edits the spectrum by varying pulse phase rather than adjusting pulse flip angle.

"pure shift" is  method for homo nuclear broad band decoupling. Sensitivity would be reduced, but spectra of only (pure) chemical shifts can be obtained by eliminating j coupling.

"pure shift" is  method for homo nuclear broad band decoupling. Sensitivity would be reduced, but spectra of only (pure) chemical shifts can be obtained by eliminating j coupling.