Metal Complexes Containing Homoleptic Diorganoselenium(II) Ligands: Synthesis, Characterization and Investigation of Optical Properties.

[()-2'-{-CH-(4)-oxazol-5-one}CHCH]Se (, L) and [()-4'-{2-CH-(4)-oxazol-5-one}CHCH]Se (, L) were prepared, structurally characterized and used as ligands to obtain new metal complexes of types [MX(L)] [L: M = Ag, X = OTf (); M = Au, X = Cl (); L: M = Ag, X = OTf (); M = Au, X = Cl ()], [(MX)(L)] [M = Ag, X = OTf, L (); L ()], [ZnCl(L)] [L (); L ()] and [Ag(L)][PF] [L (); L ()]. The silver complexes and were ionic species (1:1 electrolytes) in a MeCN solution, while in the solid state, the triflate fragments were bonded to the silver cations. Similarly, the 2:1 complexes and were found to behave as 1:2 electrolytes in a MeCN solution, but single-crystal X-ray diffraction demonstrated that compound showed the formation of a dimer in the solid state: a tetranuclear [Ag(OTf)] built through bridging triflate ligands was coordinated by two bridging organoselenium ligands through the nitrogen from the oxazolone ring and the selenium atoms in a 1κN:2κSe fashion. Supramolecular architectures supported by intermolecular C-H∙∙∙π, C-H∙∙∙O, Cl∙∙∙H and F∙∙∙H interactions were observed in compounds , and . The compounds exhibited similar photophysical properties, with a bathochromic shift in the UV-Vis spectra caused by the position of the oxazolone ring on the phenyl ring attached to the selenium atoms.