Imine coordinated 2-aminoazole complexes of (CO)5Cr(0) and (CO)5W(0), verification by structural characterisation

The synthesis and structural characterisation (IR, MS, 1H, 13C and 15N NMR and single crystal X-ray diffraction analysis) of 2-aminoazole complexes of pentacarbonyl Cr(0) and W(0) are described. When provided with endocyclic soft thioether or endocyclic hard amine, endocyclic borderline imine and exocyclic hard amine coordination sites, the softer endocyclic imine coordination site is favoured.

Graphical abstractThe structural characterisation of (CO)5M(2-aminoazole), where M = Cr or W, showed preferred endocyclic imine coordination when provided with endocyclic soft thioether or endocyclic hard amine, endocyclic borderline imine and exocyclic hard amine coordination sites. An upfield shift of 70–76 ppm is observed for the 15N NMR signal of the imine nitrogen upon coordination.Figure optionsDownload full-size imageDownload as PowerPoint slide