Concomitant Formation of N-Heterocyclic Carbene-Copper Complexes within a Supramolecular Network in the Self-Assembly of Imidazolium Dicarboxylate with Metal Ions

A new building block containing an imidazolium salt was synthesized and used for the construction of supramolecular networks with metal ions. We discovered the concomitant formation of the N-heterocyclic carbene-copper complex (CN = 2) in the self-assembly of imidazolium dicarboxylates and copper nitrates in N,N-dimethylformamide under heating. The proton in the 2 position of the imidazolium salt was abstracted, and Cu-II was reduced to Cu-I during the self-assembly process.This work was supported by a Korea Research Foundation grant funded by the Korean Government (MOEHRD, Basic Research Promotion Fund; Grant KRF-2008-313-C00455). Dr. I. G. Jung thanks the Hydrogen Energy R&D Center, a 21st century Frontier R&D Program funded by the Ministry of Science and Technology of Korea. The authors acknowledge PAL for beamline use (2008-3063-10)