Coordination networks with flexible ligands based on silver(I) salts:: Complexes of 1,3-bis(phenylthio)propane with silver(I) salts of PF6-, CF3COO-, CF3CF2COO-, CF3CF2CF2COO-, p-TsO-, and CF3SO3_

The synthesis and characterization of nine coordination networks based on 1,3-bis(phenylthio) propane, L 3, and silver(I) salts of PF6- (1), CF3COO- (2), CF3CF2COO- (3), CF3CF2CF2COO- (4), p-TsO- (5, 6), and CF3SO3- (7-9) are reported. Only 1 and other isostructural complexes with weakly coordinating anions such as ClO4- and SbF6- are of the host-guest type. In all the other complexes, the anions and the acetone molecules, when present, are coordinated to the metal. Most of the complexes studied here form a 2D-coordination network. Only 4 and 5 adopt a polymer-like chain structure. The packing of the chains of 4 is pseudohexagonal compact, while that of 5 is of the centered type. In complex 1, the silver atom is tetrahedrally coordinated to the sulfur atoms of four different ligands. The PF6- anions and acetone molecules, sandwiched between silver-ligand cationic sheets, are held through van der Waals interactions. In each of the three perfluorocarboxylates (2-4), two silver atoms are joined by the anions in a diatomic bridging mode. The Ag center dot center dot center dot Ag distances are sufficiently short to indicate weak metal center dot center dot center dot metal interactions. The dimeric units in 2 and 3 are interconnected through the ligands, thereby generating a 2D-network of neutral sheets, while, in 4, the dimeric units are bound to four ligands and a 1D-coordination polymer is generated. In the case of the sulfonate anions (p-TsO- and CF3SO3-), the crystallization solvent influences the structure adopted. Thus, in 5, 7, and 9 obtained from petroleum ether, or other nonpolar solvents, two silver atoms are bound in a double-bridge fashion, while a monobridge mode is noted for 6 and 8, both recrystallized from diethyl ether. In 8, both bridging types are observed. The thermogravimetric investigation, in the room temperature-450 degrees C interval, of complexes 1, 3, and 7, which incorporate acetone molecules in their crystal structures, reveals a two-step weight loss for 1 (the acetone molecules are lost first followed by the ligands, leaving behind the silver salt), while complexes 3 and 7 decompose in a single step to metallic silver.