Electrochemical synthesis and structural characterization of silver(I) complexes of N-2-pyridyl sulfonamide ligands with different nuclearity: influence of the steric hindrance at the pyridine ring and the sulfonamide group on the structure of the complexes.

A new series of silver complexes, [AgL], of the anionic forms of potentially bidentate N-2-pyridyl sulfonamide ligands [N-(3-methyl-2-pyridyl)-p-toluenenesulfonamide (HTs3mepy), N-(3-methyl-2-pyridyl)mesitylenesulfonamide (HMs3mepy), N-(4-methyl-2-pyridyl)-p-toluenesulfonamide (HTs4mepy), and N-(6-methyl-2-pyridyl)mesitylenesulfonamide (HMs6mepy)] have been prepared by an electrochemical procedure. In addition, heteroleptic complexes of composition [AgLL'] (L' = 1,10-phenanthroline and 2,2'-bipyridine) were obtained when the coligand L' was added to the electrolytic phase. The complexes were characterized by microanalysis, IR and (1)H NMR spectroscopy, and LSI mass spectrometry. In the cases of the compounds [Ag(Ts3mepy)](n)() (1), [Ag(4)(Ms3mepy)(4)] (2a), [Ag(Ms3mepy)](n)() (2b), [Ag(4)(Ms6mepy)(4)] (3a), [Ag(2)(Ms6mepy)(2)](n)() (3b), [Ag(2)(Ms3mepy)(2)(phen)(2)] (5), [Ag(2)(Ms6mepy)(2)phen] (7), and [Ag(2)(Ts4mepy)(2)(bipy)(2)] (8), characterization was also carried out by single-crystal X-ray diffraction. Compounds 1 and 2b present a polymer structure formed by an {AgN(2)} digonal core. Compounds 2a and 3a are tetranuclear and also have a distorted {AgN(2)} digonal core. Compound 3b is based on binuclear distorted {AgN(2)} digonal units joined by an intermolecular sulfonyl oxygen atom to produce a stairlike polymer structure. The heteroleptic complexes 5 and 8 are dimeric with a distorted {AgN(4)} tetrahedral geometry, while compound 7 shows two different geometries around the metal, distorted {AgN(2)} digonal and {AgN(4)} tetrahedral. The supramolecular structures of all species are organized by pi,pi-stacking, C-H...pi, or C-H...O interactions.