Synthesis, Characterization and Crystal Structure of Fe(III) and Ni(II) Complexes with Furan‐2,5‐Dicarbonylbis(<i>N</i>,<i>N</i>‐Diethylthiourea)

Abstract Stoichiometric reactions of furan‐2,5‐dicarbonylbis( N , N ‐diethylthiourea) H 2 L with transition metal ions including Fe 3+ and Ni 2+ in MeOH with the presence of an organic base like Et 3 N bring about two metallacyclic complexes. Chemical compositions and structures of such compounds have been investigated by elemental analyses, spectroscopic means such as HRMS, IR, NMR and X‐ray crystallography. The supportive results indicate the formation of dinuclear complexes resulting from the coordination of metal ions with ( S , O )‐chelating aroylthiourea moieties. Particularly, trivalent Fe(III) ions adopt facial octahedral geometry and, thus, form the cryptand‐like tris‐[Fe 2 (L) 3 ] ( 1 ). In contrast, divalent Ni(II) ions with cis square planar coordination spheres produce the metallacrown ether bis‐[Ni 2 (L) 2 ] ( 2 ).