Supramolecular recognition of benzene homologues in a 2D coordination polymer through variable inter-layer π–π interaction

The supermolecular recognition properties of a 2D coordination polymer, namely, [Cd2(3-tpt)(bpta)(H2O)3] (1) (3-tpt = 2,4,6-tris(3-pyridyl)-1,3,5-triazine and H4bpta = 1,1′-biphenyl-2,2′,6,6′-tetracarboxylic acid), are reported herein. Complex 1 shows a porous supermolecular framework with strong inter-layer π–π interaction from the triazine moieties of 3-tpt ligands. By utilizing its porous nature and triazine induced π–π interaction, complex 1 reveals specific supramolecular recognition and structure transformation toward benzene homologues, which is proved straightforwardly by structure investigations. Furthermore, the altered inter-layer π–π interaction of 1 in response to the molecule recognition also affects its emission properties, which indicates its potential in sensing applications.