Synthesis, structures and luminescence of multinuclear silver(i) pyrazolate adducts with 1,10-phenanthroline derivatives.

A set of silver(i) 3,5-bis(trifluoromethyl) pyrazolate adducts with 1,10-phenanthroline (L), 2,9-dimethyl-1,10-phenanthroline (neocuproine, L) and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (bathocuproine, L) was synthesized starting from trimeric silver pyrazolate AgPz. Reactions with sterically hindered L and L cause the destruction of the original trimeric core, yielding a dinuclear AgPz cycle with an unprecedented chair configuration for L, while bathocuproine L leads to the drastic rearrangement of the silver pyrazolate core into cationic Ag(L) and anionic AgPz subunits. All complexes obtained exhibit phosphorescence in the solid state. Time-dependent density functional theory calculations demonstrate their different possible emission processes, explaining their emission behavior as well as their lifetimes.