The cation-templated self-assembly of 1,4-bis(2-methyl-1H-imidazol-1-yl)butane (bmimb) with CuSCN gives rise to a novel two-dimensional network, namely catena-poly[2,2'-dimethyl-1,1'-(butane-1,4-diyl)bis(1H-imidazol-3-ium) [tetra-μ2-thiocyanato-κ(4)S:S;κ(4)S:N-dicopper(I)]], {(C12H20N4)[Cu2(NCS)4]}n. The Cu(I) cation is four-coordinated by one N and three S atoms, giving a tetrahedral geometry. One of the two crystallographically independent SCN(-) anions acts as a μ2-S:S bridge, binding a pair of Cu(I) cations into a centrosymmetric [Cu2(NCS)2] subunit, which is further extended into a two-dimensional 4(4)-sql net by another kind of SCN(-) anion with an end-to-end μ2-S:N coordination mode. Interestingly, each H2bmimb dication, lying on an inversion centre, threads through one of the windows of the two-dimensional 4(4)-sql net, giving a pseudorotaxane-like structure. The two-dimensional 4(4)-sql networks are packed into the resultant three-dimensional supramolecular framework through bmimb-SCN N-H···N hydrogen bonds.