Three new Ag(I) thiosaccharinate complexes: Synthesis, structural studies, spectral characterization and theoretical analysis

• Three new thiosaccharinate silver complexes and their structures are presented.
• The first bis(thiosaccharinate)silver anion was structurally characterized.
• A new binary one-dimensional coordination thiosaccharinate silver is presented.
• DFT calculations using OLYP and HCTH93 functionals give good 13C NMR predictions.

Three silver thiosaccharinate complexes, two of them with diverse coordination geometries controlled by the ancillary nitrogen donor ligands are presented. The dinuclear silver thiosaccharinate complex, catena-poly-[Ag2(tsac)2]·C3H7NO (1·DMF), (thiosaccharinate = thiosaccharinate anion, DMF = dimethylformamide) in the crystalline state is a one dimensional coordination polymer bridged by the thiosaccharinate ligand with a very short silver–silver distance, 2.8930(16) Å. The biquinoline silver(I) thiosaccharinate, [Ag(tsac)(2,2′-bquin)]·CH3CN (2·CH3CN), (bquin = 2,2′-biquinoline) in the crystalline state consists of a mononuclear neutral unit solvated with an acetonitrile molecule. The double complex salt, [Ag(2,4,6-coll)2][Ag(tsac)2] (3), (2,4,6-coll = 2,4,6-collidine) possesses a very unusual arrangement for a silver thiosaccharinate, one similar to an ionic silver-pyridine based structure. The complex cation is formed by two 2,4,6-trimethylpyridine molecules coordinated to the silver atom while the complex anion is composed of two thiosaccharinate anions coordinated to the silver atom. In both cation and anion, the silver center has a linear geometry with the ligands planar. The syntheses, full characterizations and crystal structures of the three complexes are described. The structures of these newly synthesized silver(I) thiosaccharinate complexes have been optimized and their structural parameters have been calculated at the B3LYP/6-31G(2d,p)/LANL2DZ level of theory. The 13C NMR chemical shifts for the DMSO solution species of (2) and (3) were calculated using DFT/EPR-III/DZP first principles calculations with B3LYP, OLYP, OPBE, HCTH93 functionals.

Molecular structures of [Ag(2,4,6-collidine)2][Ag(tsac)2] (2) and [Ag(tsac)(2,2′-bquin)] (3) (left hand side) and the graph of the calculated 13C chemical shifts of (2) and (3) using the OLYP DFT function versus the their experimental chemical shifts, together with the best linear fit and its equation and R2 value (right hand side).Figure optionsDownload as PowerPoint slide