Cuprophilicity-Induced Cocrystallization of [Cu₂(4,4‘-bpy)(CN)₂]_n Sheets and [Cu(SCN)]_n Chains into a 3-D Pseudopolyrotaxane

The cocrystallization of [Cu(SCN)]_n chains and [Cu₂(4,4‘-bpy)(CN)₂]_n (4,4‘-bpy = 4,4‘-bipyridine) layers generated a 3-D pseudopolyrotaxane compound, [Cu₂(4,4‘-bpy)(CN)₂]·[Cu(SCN)] (1), which can also be viewed as a 3-D network constructed by linkages of 2-D sheets and 1-D chains via unsupported Cu^I−Cu^I interactions. The Cu^I−Cu^I contact of 2.651(4) Å in 1 is the shortest unsupported Cu^I−Cu^I distance documented to date, indicating cuprophilic attractions.