Urothermal Syntheses, Crystal Structures, and Luminescent Properties of Two New ZnII Compounds Constructed by the Mixed Ligands of 1,2,4-Triazole and 1,4-Naphthalenedicarboxylic Acid or 2,6-Naphthalenedicarboxylic Acid

Under urothermal conditions, the self-assembly of Zn-II ions, 1,2,3-triazole, and two isomeric dicarboxylate ligands (1,4-H(2)ndc and 2,6-H(2)ndc) afforded two new metal-organic frameworks, namely [Zn(1,4-ndc)(0.5)(taz)](n)center dot n(e-urea) (1) and [Zn(2,6-ndc)(0.5)(taz)](n)center dot n(H2O)center dot n(e-urea) (2) (1,4-H(2)ndc=1,4-naphthalenedicarboxylic acid; 2,6-H(2)ndc=2,6-naphthalenedicarboxylic acid; Htaz=1,2,4-triazole; e-urea=ethyleneurea), which were further determined by single-crystal X-ray diffraction analyses, elemental analyses, powder X-ray diffraction analyses, and IR spectra. Compound 1 features a 3D pillar-layered framework with 6-connected pcu topology (pcu=alpha-Po), and compound 2 also features a 3D pillar-layered framework with 6-connected pcu topology. In addition, the thermal stabilities and solid-state photoluminescent properties of compounds 1 and 2 were also studied.