Cadmium Complexes—A Novel Family in the Coordination Chemistry of 1,2-bis(arylimino)acenaphthenes

This work presents the synthesis routes for the first representatives of cadmium complexes based on 1,2-bis(arylimino)acenaphthene (Ar-bian). The reaction of CdCl2 with bis-(2,4,6-trimethylphenylimino)acenaphthene (tmp-bian) in a 1-to-1 molar ratio led to a dimeric complex [Cd2(tmp-bian)2Cl2(µ-Cl)2] (1). Further treatment of complex 1 with silver triflate as a chloride-eliminating agent, followed by the addition of one equivalent of tmp-bian, resulted in the formation of a mixture consisting of [Cd2(tmp-bian)2(H2O)4(µ-Cl)2](OTf)2 (2) and [Cd(tmp-bian)2(OTf)2] (3). To obtain complex 3 in its individual form, a reaction of Cd(OTf)2 with two equivalents of tmp-bian was carried out. The characterization of the complexes was conducted through a range of analytical methods, including X-ray diffraction analysis, elemental analysis, as well as IR and 1H NMR-spectroscopies. Redox properties of 1 and 3 were investigated by means of cyclic voltammetry. Cyclic voltammograms revealed irreversible reduction processes centered on the tmp-bian ligand, which were confirmed by quantum chemical calculations.