Syntheses, Structures, and Properties of a Series of Polyazaheteroaromatic Core-Based Zn(II) Coordination Polymers Together with Carboxylate Auxiliary Ligands

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• 作者：Shui-Sheng Chen ; Liang-Quan Sheng ; Yue Zhao ; Zhao-Di Liu ; Rui Qiao ; Song Yang
• 刊名：Crystal Growth & Design
• 出版年：2016
• 出版时间：January 6, 2016
• 年：2016
• 卷：16
• 期：1
• 页码：229-241
• 全文大小：976K
• ISSN：1528-7505

文摘

Six Zn(II) coordination polymers, [Zn(H₂L)(Hipa-CH₃)₂]·2H₂O (1), [Zn₂(HL)₂(ipa-CH₃)] (2), [Zn₂(HL)₂(ipa-NO₂)]·2H₂O (3), [Zn₂(HL)₂(ipa-NO₂)] (4), [Zn₂(HL)(BTCA)(H₂O)]·H₂O (5), and [Zn₃(HL)₃(BTCA)] (6), were synthesized by reactions of Zn(II) salts with rigid ligand 1-(1H-imidazol-4-yl)-4-(4H-tetrazol-5-yl)benzene (H₂L) and different carboxylic acids, 5-methyl-isophthalic acid (H₂ipa-CH₃), 5-nitro-isophthalic acid (H₂ipa-NO₂), and 1,2,4-benzenetricarboxylic acid (H₃BTCA). Complexes 1 and 2 were formed under different pH values, and 1 is a one-dimensional (1D) chain extended by hydrogen bonds and π–π stacking interactions to form a three-dimensional (3D) supramolecular polymer, while 2 exhibits a uninodal 6-connected 3D architecture with (4¹²·6³)-pcu topology based on the binuclear Zn(II) secondary building units (SBUs). Polymers 3 and 4 present a pair of pseudopolymorphs with layered-pillared framework. Polymer 3 possesses Zn₂(HL^–)₂²⁺ sheets pillared by the ipa-NO₂^2– ligand to form a 3D net, while 4 builds on the [Zn₂(HL)(ipa-NO₂)]⁺ layer pillared by HL^– ligand. Complex 5 is a (3,8)-connected tfz-d 3D net with point (Schl?fli) symbol (4³)₂(4⁶·6¹⁸·8⁴) based on the tetranuclear [Zn₄(COO)₄] SBUs, while the BTCA^3– ligands act as three-connector pillars to link adjacent [Zn₃(HL^–)₃]^3– layers into a 3D net for 6. Complexes 1–6 exhibit intense light blue emission in the solid state at room temperature, and activated sample 6 shows highly selective CO₂ uptake over N₂ and H₂.