The synthesis, structure, and luminescence of two silver(I)-dppm complexes based on sulfate anion and nitrogen heterocyclic ligands

At ambient temperature, two silver(I) complexes [Ag4(SO4)2(dppm)4]·5CH3CH2OH·1/2H2O (1) and [Ag2(SO4)(dppm)2(2-ampz)]·CH3OH·H2O (2) (dppm = bis(diphenylphosphino)methane, 2-ampz = 2-aminopyrazine) were obtained by the reaction of Ag2SO4 with dppm in the presence of pyrazine or 2-aminopyrazine. They are characterized by IR, X-ray crystallography, luminescence and 1H, 31P NMR spectroscopy. Complex 1 is a tetranuclear cluster. In complex 2, the units [Ag2(SO4)(dppm)2] are connected by 2-aminopyrazine to form a 1D linear polymer. Due to the subtle interactions of different nitrogen heterocyclic ligands with silver ions, two SO42− anions in 1 adopt μ3-O, O′, O′ and unique μ4-O, O, O′, O′ bonding modes respectively, while SO42− anion in 2 adopts μ-O, O′ bonding mode.