Two 2D Zn(II) coordination polymers assembled from thiophene dicarboxylate and flexible N-(4-pyridylmethyl)imidazole derivatives: syntheses, crystal structures, and photoluminescent properties

Abstract

Two 2D Zn(II) coordination polymers, formulated as [Zn(μ 2-tdc)(μ-pmid)] (1), {[Zn(μ 2-tdc)(μ-pmmid)2·4H2O]}n (2) (H2tdc = 2,5-thiophenedicarboxylic acid, pmid = 1-(4-pyridylmethyl)imidazole; pmmid = 1-(4-pyridylmethyl)-2-methylimidazole) have been synthesized by reactions of Zn(OAc)2·2H2O and H2tdc with flexibleN-(4-pyridylmethyl)imidazole derivatives under the mild reaction conditions and characterized by single-crystal X-ray diffraction and other physicochemical methods. Structure determination demonstrates compound 1 displays a 2-fold 2D → 2D parallel interpenetrating structure, while compound 2 shows a 2D non-interpenetrating network. These results reveal that the substitute group in such N-(4-pyridylmethyl)imidazole derivatives might be the main factor resulting in these interpenetrating/ non-interpenetrating structures.Furthermore, compounds 1 and 2 show different thermal stabilities and strong solid-state luminescence emissions.