Structural Prediction of Bis{(di-p-anisole)-1,4-azabutadiene}-bis[triphenylphosphine]ruthenium(II) Using 31P NMR Spectroscopy

Meng Guan Tay,Ruwaida Asyikin Abu Talip,Kok Tong Ong,Ying Ying Chia,Thareni Lokanathan

doi:10.1155/2016/7095624

Meng Guan Tay, Ruwaida Asyikin Abu Talip + Show 3 more

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https://doi.org/10.1155/2016/7095624

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Abstract

The present paper reports the use of 31P NMR spectroscopy to predict the isomer structures of [bis{4-methoxy-phenyl-[3-(4-methoxy-phenyl)-allylidene]-amino}]-bis[triphenylphosphine]ruthenium(II), also known as bis{(di-p-anisole)-1,4-azabutadiene}-bis[triphenylphosphine]ruthenium(II), complexes. The complexation reaction was carried out under refluxing condition of (di-p-anisole)-1,4-azabutadiene (compound 1), triphenylphosphine (PPh3), and ruthenium chloride in the ratio of 2 : 2 : 1 for five hours. In addition, ruthenium(II) complexes were also characterized using FTIR and UV-Vis spectroscopy to support the formation of ruthenium(II) complexes. 31P NMR spectroscopic study on ruthenium(II) complexes suggested that there are three isomers present after the complexation reaction and all the ruthenium complexes demonstrate octahedral geometry.

Highlights

Nuclear magnetic resonance (NMR) spectroscopy is an essential instrument in chemistry as it can determine the structure of a molecule, the presence of impurities in a sample and the rate of formation as well as degradation of a compound
One of the well-known examples is the use of 31P NMR spectroscopy to determine the Wilkinson hydrogenation mechanism by identifying the coupling patterns among phosphine ligands and the coupling constants between phosphine ligands as well as rhodium(I) metal centre [6]
In our long term research interest in ruthenium(II) complexes synthesis, we used-1,4-azabutadiene (1) and triphenylphosphine (PPh3) as the ligands to react with ruthenium trichloride under reflux condition

Summary

Introduction

Nuclear magnetic resonance (NMR) spectroscopy is an essential instrument in chemistry as it can determine the structure of a molecule, the presence of impurities in a sample and the rate of formation as well as degradation of a compound. Even in 1970s, NMR has already been used to determine the cancer formation which offered a simple, fast, and low cost method to identify cancer formation [1,2,3]. The use of 31P NMR to identify the structure of a complex containing phosphine ligands is very common [4, 5]. One of the well-known examples is the use of 31P NMR spectroscopy to determine the Wilkinson hydrogenation mechanism by identifying the coupling patterns among phosphine ligands and the coupling constants between phosphine ligands as well as rhodium(I) metal centre [6]. The products formed were checked by using 31P NMR spectroscopy and the results found in the spectra are worth to be discussed in the present communication

Methodology

Results and Discussion

Conclusion