Synthesis and porous crystal structure of 1D zigzag π-stacked supramolecular polymer based on a new binuclear AgI thiacalix[4]arene complex bearing two 2,2′-bipyridyl moieties

Abstract

A new lower-rim 1,3-disubstituted thiacalix[4]arene derivative, bearing chelating 2,2′-bipyridyl groups, was synthesized and characterized in solution by ¹H and ¹³C NMR spectroscopy. The reaction of this compound with Ag^I cations afforded a binuclear cationic complex, in which thiacalix[4]arene acts as a bis-N,N,S-donor tridentate ligand. The supramolecular self-assembly of the Ag^I complex in the crystalline phase resulted in the formation of an extended 1D zigzag-like polymer through π-stacking interactions between bipyridyl substituents of the adjacent binuclear Ag^I thiacalix[4]arene complexes. The crystal packing of these π-stacked chains displays a porous supramolecular structure containing channels with a size of 8.8×9.4 Ų and possessing a free unit cell volume of 32.1%.