Two　3D　coordination　polymers　with　different　structure　motifs,　[Zn-2(PCPA)(2)(IN)(2)](n)　(1)　and　[Co(PCPA)(IN)](n)　(2)　(PCPA　=　p-chlorophenoxyacetate,　IN　=　isonicotinate),　first　constructed　from　mixed　rigid　and　flexible　carboxylate　ligands,　have　been　obtained　under　hydrothermal　condition　and　characterized　by　elemental　analyses,　IR　spectra,　thermogravimetric　analysis,　fluorescent　spectra　and　single　crystal　X-ray　diffraction　analysis.　The　most　intriguing　structural　feature　is　that　each　complex　exhibits　both　infinite　helical　Zn(mu(2)-carboxylate)　or　Co(mu(3)-carboxylates)　chain　units　with　2(1)　helices　and　zigzag　M-2(IN)(2)　(M　=　zinc　and　cobalt)　chain　units　by　reason　of　two　different　carboxylate　ligands　coordinating　to　metal　centers.　Additionally,　compounds　1　and　2　show　similar　blue　fluorescence　in　the　solid　state　at　room　temperature.　(C)　2006　Elsevier　Inc.　All　rights　reserved.