2D POLYMERIC SILVER(I) COMPLEXES CONSISTING OF MARKEDLY UNDULATED SHEETS OF SQUARES - X-RAY CRYSTAL-STRUCTURES OF [AG(PPZ)(2)](BF4) AND [AG(PYZ)(2)](PF6) (PPZ=PIPERAZINE, PYZ=PYRAZINE)

Two novel silver(I) coordination polymers, [Ag(ppz)(2)](BF4) (1) and [Ag(pyz)(2)](PF6) (2) (ppz = piperazine, pyz = pyrazine), are prepared. Their crystal structures are found to contain markedly undulated 2D networks of distorted squares of Ag+ cations, in tetrahedral (1) and disphenoidal coordination geometries (2)