Di(4‐pyridyl) Sulfoxide as an Angled Building Block for Zigzag‐Chain Silver(I) Complexes Stabilized by Supramolecular O=S···π Interactions

The angled ligand di‐4‐pyridyl sulfoxide ( L 1 ) and five of its silver(I) complexes that bear various counteranions, namely, {[Ag( L 1 )](BF 4 ) · (CH 3 CN)} ∞ ( 1 ), {[Ag( L 1 )(CF 3 SO 3 )] · (CH 3 CN)} ∞ ( 2 ), {[Ag( L 1 )(CF 3 CO 2 )] · CH 3 CN} ∞ ( 3 ), {[Ag( L 1 )(NO 3 )] · H 2 O} ∞ ( 4 ), and {[Ag 2 ( L 1 ) 2 (SO 4 )] · 6H 2 O} ∞ ( 5 ), have been synthesized and characterized by X‐ray crystallography, FTIR spectroscopy, elemental analysis, and luminescent emission measurements. Complexes 1 – 5 exhibit a common [Ag( L 1 )] n n + zigzag‐chain motif generated by the μ 2 ‐ N , N ‐bridging L 1 ligand. The common dominant intermolecular O=S(sulfinyl) ··· π(pyridyl) interaction with the S=O group embraced by the pyridyl wings of an adjacent butterfly‐like L 1 ligand plays a crucial role in the supramolecular aggregation of 1 – 5 . Replacement of the sulfinyl (S=O) group of L 1 by a sulfonyl (O=S=O) group to yield related ligand L 2 led to {[Ag( L 2 )](NO 3 )} ∞ ( 6 ) ( L 2 = di‐4‐pyridyl sulfone), which exhibits a markedly different supramolecular architecture from those of 1 – 5 because of the absence of the O=S(sulfinyl) ··· π(pyridyl) contact. Density functional calculations confirm that there is a π orbital interaction between the sulfinyl S atom and the intermolecular pyridyl rings, which significantly contributes to the O=S ··· π affinity.