Elsevier

Inorganic Chemistry Communications

Volume 99, January 2019, Pages 156-159
Inorganic Chemistry Communications

Short communication
Ruthenium(II) p-cymene complexes bearing 2‑(1,2,4‑triazol‑3‑yl)pyridines: Linkage isomerism and related NMR/DFT studies

https://doi.org/10.1016/j.inoche.2018.11.020Get rights and content

Highlights

  • Several new Ruthenium(II) p-cymene complexes bearing pyridyl-1,2,4-triazoles were synthesized and characterized

  • A simple and efficient 1H NMR criterion for determining coordination mode of pyridyl-1,2,4-triazoles is proposed

  • Tautomeric and linkage isomerization equilibria are investigated with the use of 1H NMR and DFT studies

  • Crystal structure of one of the complexes is presented

Abstract

A series of ruthenium(II) p-cymene complexes bearing 2‑(1,2,4‑triazol‑3‑yl)pyridines was obtained. A simple and efficient 1H NMR spectroscopic criterion for determining coordination mode of the 2‑(1,2,4‑triazol‑3‑yl)pyridines as ligands in the complexes is described. The validity of the criterion is corroborated by DFT calculations using B3LYP functional and mixed LANL2DZ/6-31**G basis set. Also, the influence of the size of the substituent in 5-position of the triazole ring on linkage isomers' ratio is discussed.

Graphical abstract

A series of Ruthenium(II) p-cymene complexes bearing 2‑(1,2,4‑triazol‑3‑yl)pyridines was obtained. A simple and efficient 1H NMR spectroscopic criterion for determining coordination mode of the 2‑(1,2,4‑triazol‑3‑yl)pyridines as ligands in the complexes is described. The validity of the criterion is corroborated by DFT calculations using B3LYP functional and mixed LANL2DZ/6-31**G basis set. Also, the influence of the size of the substituent in 5-position of the triazole ring on linkage isomers ratio is discussed.

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Section snippets

Conclusions

In conclusion, new ruthenium(II) p-cymene half-sandwich complexes bearing 2‑(1,2,4‑triazol‑3‑yl)pyridines were synthesized and characterized. 1H NMR coupled with DFT studies show that the most efficient-yet-simple tool for ascertaining the coordination mode of N-unsubstituted 2‑(1,2,4‑triazol‑3‑yl)pyridines in such complexes is the width of the 3PyH signal: in N2-isomers' 1H NMR spectra it is significantly broadened whereas in the case of N4-isomers it is sharp. It appears that the complexation

Notes

The authors declare no competing financial interests.

Acknowledgments

We thank Chemistry Department of Taras Shevchenko National University of Kiev for support and Dr. S. Shova (Petru Poni Institute of Macromolecular Chemistry) for XRD data collection.

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