“…On the other hand, only a limited number of copper(I) coordination polymers containing a Cu−CO unit have been structurally characterized. All reported copper(I) carbonyl polymers with polydentate ligands, either with N-containing bridging ligands such as diazabicyclo[2.2.2]octane, piperazine, N , N ‘-dimethypiperazine, and 1,2-di-2-pyridylethylene 11c,f or with polyoxygen anions such as ethyl sulfonate, hydrogen sulfate, and trichloroacetate, 11a,d,e exhibit chain structures. Only [CuCl(CO)] n , a compound without a supporting organic ligand, shows a hexagonal honeycomb layer structure,11b and it represents the only reported two-dimensional copper(I) carbonyl polymer.…”