Structural variations in copper(I) iodide coordination polymers of sulfide and disulfide containing flexible 3-substituted pyridine ligands

Abstract The three-substituted dipyridyl ligand bis(3-pyridylmethyl)sulfide ( L 1 ) was prepared by the reaction of 3-(chloromethyl)pyridine hydrochloride with thioacetamide under basic conditions. L 1 was reacted with CuI to give complexes with 1:2 and 1:1 molar ratios. Crystal structures of [(CuI) 2 ( L 1 )] ∞ ( 1 ) and [CuI( L 1 )] ∞ ( 2 ) were determined. In complex 1 the CuI species formed a one-dimensional staircase polymer to which L 1 was bound in a side-by-side fashion with π–π interactions between the ligands on each side. Complex 2 consisted of a one-dimensional ribbon polymer of metallomacrocycles formed from two L 1 ligands bridging Cu 2 I 2 dimers which were fused within the macrocyclic ring. The analogous disulfide ligand bis(3-pyridylmethyl)disulfide ( L 2 ) was prepared by oxidation of the corresponding thiol 3-(sulfanylmethyl)pyridine. L 2 was reacted with CuI in 1:2 and 1:1 molar ratios and products isolated but only the 1:1 product was able to be crystallised. The crystal structure of [CuI( L 2 )] ∞ ( 3 ) consisted of a one-dimensional ribbon polymer of metallomacrocycles formed from two L 2 ligands linked through Cu 2 I 2 dimers. The difference in the metallomacrocycle linking between the related structures 2 and 3 was attributed to the difference in ligand conformation.