Synthesis, Luminescence, and Electrochemistry of Mix-Capped Trinuclear Copper(I) Acetylide Complexes. X-ray Crystal Structures of Cu3(μ-dppm)3(μ3-η1-C⋮CC6H4OMe-p)(μ3-η1-C⋮CC6H4OEt-p)PF6 and Cu3(μ-dppm)3(μ3-η1-C⋮CC6H4OMe-p)(μ2-η1-C⋮CC6H4NO2-p)PF6 | Synapse