New Coordination Polymers of Copper(I) and Silver(I) with Pyrazine and Piperazine: A Step Toward "Green" Chemistry and Optoelectronic Applications.

Five coordination polymers and one hexanuclear cluster have been obtained, and their crystal structures were determined upon reaction of Cu(I) or Ag(I) precursors with pyrazine (Pyz) or piperazine (Ppz). Five complexes are mixed-imine-ligand with anionic-fluorinated pyrazolate [3,5-(CF)Pz] ([Pz]) besides Pyz or Ppz, whereas the sixth had the neutral diimine as a single chromophore. Complexes 1-3 are isomers of the same Cu/Pz/Pyz composition with the same or different unit cell stoichiometry, namely, {Cu[3,5-(CF)Pz](Pyz)(CHCl)} (1·CHCl), {Cu[3,5-(CF)Pz]}(Pyz)·toluene} (2·toluene), and {Cu[3,5-(CF)Pz](Pyz)·1.