Dinuclear, tetranuclear and polynuclear copper(I)-ethylene-bridged bis-N-heterocyclic carbene complexes

New ethylene group bridged N-vinyl or -propylene bisimidazolium dibromide salts were synthesized and treated with CuI in the presence of 2.5 equivalent of potassium tert-butoxide to yield the novel tetra nuclear copper(I)-NHC (N-heterocyclic carbene) derivatives. Interestingly, the dinuclear copper(I)-NHC and two dimentional copper(I)-NHC grid molecules were isolated, when these reactions were carried out in the presence of 1.1 equivalent of potassium tert-butoxide. The two dimentional copper(I)-NHC grid is constructed by a rare Cu3I3 cluster core. The coordination environments of copper centers in Cu3I3 core are not comparable