Reaction of ethyl (2Z)-cyano-6-methoxyquinolin-2(1H)-ylidene-ethanoate (L) with rhenium carbonyls: Structural and computational studies on the rhenium(I) compound cis-BrRe(CO)4L

The reaction of the heterocycle ethyl (2Z)-cyano-6-methoxyquinolin-2(1H)-ylidene-ethanoate (L) with different rhenium carbonyls to give cis-BrRe(CO)4L (1) is reported. X-ray crystallography reveals that the heterocyclic ligand coordinates to the rhenium center via the nitrile moiety and cis to the bromine group in 1. Compound 1 has been characterized in solution by IR and NMR (1D and 2D) spectroscopy, and the complete assignment of the 1H and 13C NMR resonances associated with the coordinated heterocycle established. The redox properties and the bonding in 1 have been explored by cyclic voltammetry and DFT calculations, respectively. The mechanism for the formation of 1, starting from BrRe(CO)5 and L, has been studied computationally, and the cis product is computed to be 16.8 kcal/mol more stable than trans-BrRe(CO)4L.

The reaction of the heterocycle ethyl (2Z)-cyano-6-methoxyquinolin-2(1H)-ylidene-ethanoate (L) with different rhenium carbonyls to give cis-BrRe(CO)4L (1) is reported. The mechanism for the formation of 1, starting from BrRe(CO)5 and L, has been studied computationally, and the cis product is computed to be 16.8 kcal/mol more stable than trans-BrRe(CO)4L.Figure optionsDownload as PowerPoint slide