N,N-dialkyl-N'-ferrocenoylthioureas and ferrocene-1,1'-dicarbonic-acid-di-N,N-dialkylthioureides as ligands for transition metals: Synthesis, acid-dissociation constants, X-ray structure determination, and EPR-single crystal investigation

Reaction of ferrocenoylisothiocyanate or ferrocene-1,1'-dicarbonic acid -diisothiocyanate with secondary amines gives N,N-dialkyl-N'-ferrocenoylthioureas or the respective ferrocene-1,1'-dicarbonic acid-di-N,N-dialkyl-thioureides. The former yield neutral complexes with transition metal ions (Ni2+, Cu2+, Co2+, Pt2+, Fe3+). The acid dissociation constants of the ligands were determined. The EPR spectra of a bis-(N,N-di(n)butyl-N'-ferrocenoylthioureato)copper(II) single crystal are discussed. The X-ray structure determination of ferrocene-1,1'-dicarbonic acid-di-N,N-diethyl-thioureide and its different behaviour against Ni2+ and Cu2+ is presented.