Anion-templating self-assembly of [Cu2(OMe)2]2+ SBUs depending on the size of the anion in the solid state

The [Cu2(OMe)2]2+ secondary building units (SBUs) are self-assembled into 3D cages or an infinite 1D coordination polymer depending on whether the counter-anion exerts a size-templating effect or not. Small anions of [BF4]− and [ClO4]− make two SBUs interconnect each other with four btp (=2,6-bis(N1-1,2,4-triazolyl)pyridine), leading the anion-encapsulated 3D cages. Meanwhile the triflate anion ([OTf]−) does not induce a cage structure, leading instead to an infinite 1D coordination polymer.