Multidimensional frameworks assembled from silver(I) coordination polymers containing flexible bis(thioquinolyl) ligands: role of the intra- and intermolecular aromatic stacking interactions.

The two flexible multidentate ligands 1,3-bis(8-thioquinolyl)propane (C3TQ) and 1,4-bis(8-thioquinolyl)butane (C4TQ) were reacted with AgX (X = CF3SO3- or ClO4-) to give four new complexes:  {[Ag(C3TQ)](ClO4)}n 1, {[Ag(C3TQ)](CF3SO3)}n 2, {[Ag2(C4TQ)(CF3SO3)(CH3CN)](CF3SO3)}n 3, and {[Ag(C4TQ)](ClO4)}n 4. All complexes have been characterized by elemental analysis, IR, and 1H NMR spectroscopy. Single-crystal X-ray analysis showed that chain structures form for all complexes in which the quinoline rings interact via various intra- (1) or intermolecular (2, 3, and 4) π−π aromatic stacking interactions, which in the latter cases results in multidimensional structures. Additional weak interactions, such as Ag···O and Ag···S contacts and C−H···O hydrogen bonding, are also present and help form stable, crystalline materials. It was found that the (CH2)n spacers (n = 3 or 4) affect the orientation of the two terminal quinolyl rings, thereby significantly influencing the specific framework structure that forms. I...