Related Experiment Video
Updated: Oct 2, 2025

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
Published on: September 17, 2017
Solid-State Photo-NMR Study on Light-Induced Nitrosyl Linkage Isomers Uncovers Their Structural, Electronic, and
Axel Gansmüller1, Artem A Mikhailov2, Gennadiy A Kostin2
1Université de Lorraine, CNRS, CRM2, F-54000 Nancy, France.
Abstract:
A light-induced linkage NO isomer (MS1) in trans-[Ru(15NO)(py)419F](ClO4)2 is detected and measured for the first time by solid-state MAS NMR. Chemical shift tensors of 15N and 19F, along with J(15N-19F) spin-spin couplings and T1 relaxation times of MS1, are compared with the ground state (GS) at temperatures T < 250 K. Isotropic chemical shifts (15N and 19F) are well resolved for two crystallographically independent cations (A and B) [Ru(15NO)(py)419F]2+, allowing to define separately both populations of MS1 isomers and thermal decay rates for two structural sites. The relaxation times T1 of 19F in the case of GS (30/38.6 s for sites A/B) and MS1 (11.6/11.8 s for sites A/B) indicate that both isomers are diamagnetic, which is the first experimental evidence of diamagnetic properties of MS1 in ruthenium nitrosyl. After light irradiation (λ = 420 nm), the NO ligand rotates by nearly 180° from F-Ru-N-O to F-Ru-O-N, whereby the isotropic chemical shifts of δiso(15N) increase and those of δiso(19F) decrease. The J(15N-19F) couplings increase from 2J(15N-Ru-19F)GS = 71 Hz to 3J(15N-O-Ru-19F)MS1 = 105 Hz. These results are interpreted on the basis of DFT-CASTEP calculations including Bader-, Mulliken-, and Hirshfeld-charge density distributions of both states.
Related Concept Videos
Structural Isomerism
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
NMR Spectroscopy Of Amines
NMR Spectroscopy: Spin–Spin Coupling
Other Nuclides: 31P, 19F, 15N NMR
While fluorine-19 and phosphorous-31 have high natural abundances (100%) and positive gyromagnetic ratios, nitrogen-15 has a low natural abundance and a negative gyromagnetic ratio. However, nitrogen-15 is still preferred over nitrogen-14 (which has a...
Nuclear Overhauser Enhancement (NOE)
¹H NMR: Complex Splitting
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...

