6-(Thien-2-yl)-2,2'-bipyridine: presenting an N^N or N^N^S donor set to silver(I)

Reaction of two equivalents of 6-(thien-2-yl)-2,2′-bipyridine (1) with AgPF6 in CH2Cl2 produces the mononuclear complex [Ag(1)2][PF6] in which the Ag+ ion is in a flattened-tetrahedral Ag(N^N)2-environment in the solid state; the thiophenyl substituents are not coordinated. When equal equivalents of AgPF6 and 1 react in CH2Cl2, a mixture of [Ag(1)2][PF6] and {2[Ag3(1)4][PF6]3·3H2O}n is formed. Single crystal X-ray diffraction confirms that {2[Ag3(1)4][PF6]3·3H2O}n is a coordination polymer, with a helical arrangement of ligands enveloping a chain of silver(I) ions. Distances between adjacent pairs of Ag atoms are 3.087(1), 3.884(1) and 4.763(1) Å, with only one in three pairs exhibiting argentophilic interaction.