Cyclohexanone selenosemicarbazone: A convenient starting material for the preparation of functionalised selenosemicarbazones and their Pt and Pd complexes

The reaction of hydrazine hydrate with KSeCN in acidic aqueous ethanol in the presence of cyclohexanone affords cyclohexanone selenosemicarbazone in good yields. Cyclohexanone selenosemicarbazone was converted into various functionalised selenosemicarbazones by treatment with aldehydes. Salicylaldehyde selenosemicarbazone and its 1,2-naphthyl-derivative were prepared and reacted with some Pd(II) and Pt(II) phosphine complexes to give compounds of the type [M(LSe)(P)] where M = Pt and Pd, LSe is the doubly deprotonated selenosemicarbazone and P a monodentate phosphine. In these complexes the ligands act as tridentate, dianionic [Se–N–O]2- ligands, which was confirmed by single-crystal X-ray diffraction of the Pd derivative.

Graphical abstractSynopsisThe reaction of hydrazine hydrate with KSeCN and cyclohexanone in acidic aqueous ethanol gives cyclohexanone selenosemicarbazone. This was converted into various functionalised selenosemicarbazones by treatment with aldehydes. Salicylaldehyde selenosemicarbazone and its 1,2-naphthyl-derivative were prepared and reacted with some Pd(II) and Pt(II) phosphine complexes. In these complexes the ligands act as tridentate, dianionic [Se–N–O]2− ligands.Figure optionsDownload full-size imageDownload as PowerPoint slide