Supramolecular recognition of benzene homologues in a 2D coordination polymer through variable inter-layer π-π interactionElectronic supplementary information (ESI) available. CCDC for 1: 1563792; CCDC for 2: 1833937; CCDC for 3: 1833938. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c8ce00505b

The supermolecular recognition properties of a 2D coordination polymer, namely, [Cd 2 (3-tpt)(bpta)(H 2 O) 3 ] ( 1 ) (3-tpt = 2,4,6-tris(3-pyridyl)-1,3,5-triazine and H 4 bpta = 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. A 2D network 1 was synthesized. After immersing 1 in benzene homologues, the crystal structures of 2 and 3 were gotten, demonstrating that the introduction of benzene homologues has transformed the π-π packing mode, further altering the host framework and fluorescence performance.