Silver(I) complexes with diorganochalcogen ligands of type (2-MeC6H4CH2)2E (E = S, Se). Synthesis, structure and antiproliferative activity

Silver(I) complexes of types [Ag(X){E(CH2C6H4Me-2)2}] [E = S, X = CF3SO3 (1), NO3 (2), ClO4 (3); E = Se, X = CF3SO3 (4), NO3 (5), ClO4 (6)] and [Ag(X){E(CH2C6H4Me-2)2}2] [X = CF3SO3, E = S (7), Se (8); X = ClO4, E = S (9), Se (10)] were prepared by reacting the diorganochalcogenides (2-MeC6H4CH2)2E [E = S (L1), Se (L2)] with the appropriate silver(I) salt in a 1:1 and a 2:1 molar ratio, respectively. The ligands and the Ag(I) complexes were characterized by multinuclear NMR spectroscopy (1H, 13C{1H}, 19F{1H}, 77Se{1H}, as appropriate), ESI+ mass spectrometry, elemental analysis and IR spectroscopy. The crystal and molecular structures of the ligand L1 and the complexes 2, 5, 7, 8 and 9 were determined by single-crystal X-ray diffraction. The molar conductivity of the reported metal complexes showed their behaviour as 1:1 electrolytes in solution, while in solid state the inorganic anionic ligand is coordinated to silver by O-Ag bonds. Preliminary results showed that the silver(I) complexes bearing triflato ligands have in vitro promising antiproliferative activity against the murine melanoma B16.F10 cells.