Expanding the Library of Dithiocarbamato-Carboxylate Metalloligands for Heterobimetallic Coordination Networks toward Copper and Gold

With [Cu-(L)(2)](4-) and [Au-(L)(2)](3-) (L = N-dithioato-iminodiacetate), two new potentially useful metalloligands for the construction of heterobimetallic coordination networks (CNs) were investigated. As compared to other metal-(II) bis-(DTCC) metalloligands (DTCC = dithiocarbamato carboxylate), the Cu-(II) complexes are structurally more diverse and enable potentially interesting redox and magnetic properties. Au-(III) forms structurally related bis-(DTCC) complexes and allows for the construction of new coordination-polymeric assemblies due to its +3 charge. The preparation of heterobimetallic coordination networks was demonstrated with Sr2+ ions as a representative example, thus obtaining the products Sr-2[Cu-(L)(2)], Sr-3[Au-(L)(2)](2), and Sr-5(OAc)-[Au-(L)(2)](3), in the form of well-defined hydrates. For comparison purposes, the group-10 analogs Sr-2[Ni-(L)(2)] and Sr-2[Pd-(L)(2)] were also prepared. The products were characterized by thermal, spectroscopic, electrochemical, and X-ray diffraction methods.