NMR Spectroscopy and Quantum Numbers

A spectroscopic technique used to analyze the electronic structure of molecules and properties of chemical species, based on the absorption of radio-frequency electromagnetic radiation by atomic nuclei.

Nuclei with spin (e.g., 1H, 19F, 31P),possessing powerful magnetic properties that can be analyzed by NMR.

A value describing the angular momentum or intrinsic magnetic properties of a nucleus, determining whether it's NMR-observable. (I=0 nuclei are not observable).

Two energy levels resulting from an applied magnetic field.Nuclei with spin align either with or against the field.

The part of the electromagnetic spectrum used in NMR spectroscopy, with frequencies from 10→1000 MHz.

Commonly studied nuclei in NMR, especially for biological samples, due to their magnetic properties.

NMR spectroscopy aids in studying, identifying and characterizing coordination compounds

A powerful spectroscopic method used to determine molecular structures in solution and pure liquids.

The ability of NMR to detect a signal from a nucleus; higher sensitivity means easier detection.

The percentage of a particular isotope of an element naturally present.

A measure of the magnetic strength of a nucleus.

The difference in resonance frequency of a nucleus compared to a reference standard (usually TMS).

A reference compound in NMR spectroscopy used to define 0 ppm chemical shift.

The reduction in the effective magnetic field experienced by a nucleus due to the surrounding electrons.

A unit used to express chemical shifts in NMR, showing the tiny difference in frequencies.

Low energy in NMR leads to weak signals, poor sensitivity, and longer experiments.

The magnetic field experienced by a nucleus, composed of the external static field (B0) and a shielding field from surrounding electrons.

A measure of the difference in resonance frequency of a nucleus relative to a standard (often TMS).

Shielding: nucleus experiences a lower effective field compared to the standard. Deshielding: nucleus experiences a higher effective field compared to the standard.

The common reference standard for 1H, 13C, and 29Si NMR spectra, used to define the 0 ppm chemical shift.

The splitting of NMR signals due to the interaction of nuclear spins in neighboring atoms.

The area under an NMR signal, that provides information about the relative number of different nuclei present in the signal.

The coupling of nuclear spins of different isotopes.

An instrument that uses magnetic fields and radio waves to determine the structure and properties of molecules.

Signal broadening in nuclear magnetic resonance (NMR) spectroscopy happens when the width of a signal in an NMR spectrum becomes comparable to the chemical shift range of the nucleus being observed.

The typical chemical shift range for hydrogen (1H) nuclei in NMR experiments is approximately 10 parts per million (ppm).

Platinum-195 (195Pt) nuclei have a much larger chemical shift range (approximately 16,000 ppm) compared to hydrogen (1H).

Large chemical shift ranges in NMR can lead to large anisotropic linewidths, which contribute to signal broadening.

Broad signals in NMR spectroscopy can be a challenge, and, as a result, it can be hard to get useful data from the NMR data.

Coupling between nuclei of the same isotope, detectable when the nuclei are in chemically different locations.

A group of closely spaced signals in an NMR spectrum originating from spin-spin coupling.

Interaction between the magnetic moments of two or more nuclei affecting their resonance signals in NMR.

In GeH4, the central line (4 equivalent Hs) is surrounded by satellites from 73Ge, showing a 10-line multiplet (2*9/2+1 =10).

The 19F NMR spectrum shows split signals (doublet and triplet) due to different chemical environments of the 19F nuclei, distinguishing it from other structural arrangements

Intrinsic angular momentum of atomic nuclei, leading to their magnetic moment and NMR signal.

Difference in resonance frequency of an NMR signal depending on the local chemical environment.

NMR measurements on solid samples, often showing broader signals than solution-state NMR due to anisotropic interactions.