Cadmium(II) Coordination Polymers of 4-Pyr-poly-2-ene and Carboxylates: Construction, Structure, and Photochemical Double [2 + 2] Cycloaddition and Luminescent Sensing of Nitroaromatics and Mercury(II) Ions

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• 作者：Wei-Jie Gong ; Zhi-Gang Ren ; Hong-Xi Li ; Jian-Guo Zhang ; Jian-Ping Lang
• 刊名：Crystal Growth & Design
• 出版年：2017
• 出版时间：February 1, 2017
• 年：2017
• 卷：17
• 期：2
• 页码：870-881
• 全文大小：1078K
• ISSN：1528-7505

文摘

Solvothermal reactions of Cd(NO₃)₂·4H₂O with 4-pyr-poly-2-ene (ppene) in the presence of benzene-1,2-dicarboxylic acid (1,2-H₂BDC), benzene-1,3-dicarboxylic acid (1,3-H₂BDC), benzene-1,4-dicarboxylic acid (1,4-H₂BDC), benzene-1,3,5-tricarboxylic acid (1,3,5-H₃BTC), or 4,4′-oxidibenzoic acid (4,4′-H₂OBA) afforded five Cd(II) coordination polymers [Cd(ppene)(1,2-BDC)]_n (1), [Cd(ppene)(1,3-BDC)]_n (2), [{Cd(ppene)(1,4-BDC)}·MeCN]_n (3) (Liu et al. Inorg. Chem. Commun. 2015, 58, 1−4), [{Cd(ppene)(1,3,5-HBTC)}·0.5(ppene)]_n (4), and [Cd(ppene)(4,4′-OBA)]_n (5), respectively. Upon UV light irradiation, 1, 3, and 4 can undergo a double [2 + 2] cycloaddition reaction to yield their corresponding photoproducts including [Cd₂(4-tp-3-lad)(1,2-BDC)₂]_n (1a, 4-tp-3-lad = 2,3,5,6-tetra(pyridin-4-yl)bicyclo[2.2.0]hexane), [{Cd₂(4-tp-3-lad)(1,4-BDC)₂}·2MeCN]_n (3a), and [{Cd₂(4-tp-3-lad)(1,3,5-HBTC)₂}·(ppene)]_n (4a) in a single-crystal-to-single-crystal manner. Compounds 1, 2, 4, 5, 1a, 3a, and 4a have been structurally characterized by elemental analysis, infrared spectroscopy, powder X-ray diffraction, and single-crystal X-ray diffraction. Compounds 1, 1a, 4 and 4a consist of two-dimensional (2D) (4,4) networks, in which one-dimensional (1D) [Cd₂(1,2-BDC)₂]_n or [Cd₂(1,3,5-HBTC)₂]_n chains are linked by ppene or 4-tp-3-lad bridges. 2 has a three-dimensional (3D) 3-fold interpenetrated framework formed from bridging 1D [Cd₂(1,3-BDC)₂]_n double chains by ppene ligands. Compounds 3a and 5 contain 3D frameworks assembled by linking 2D [Cd₂(1,4-BDC)₂]_n or [Cd₂(4,4′-OBA)₂]_n networks by 4-tp-3-lad or ppene bridges. In the three photoreactions, each ppene ligand had its two conjugated C═C bonds parallel to those of the neighboring ppene. The resulting ppene pair was transformed into the only product, 4-tp-3-lad, through a unique double [2 + 2] cycloaddition. Photoluminescence properties of these compounds in water were also investigated. Compound 3a as a representative example was proven to be an efficient probe for dual detections of nitroaromatics and Hg²⁺ in aqueous solutions.