Bioactive Silver–Organic Networks Assembled from 1,3,5-Triaza-7-phosphaadamantane and Flexible Cyclohexanecarboxylate Blocks

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• 作者：Sabina W. Jaros ; M. Fátima C. Guedes da Silva ; Jarosław Król ; M. Conceição Oliveira ; Piotr Smoleński ; Armando J. L. Pombeiro ; Alexander M. Kirillov
• 刊名：Inorganic Chemistry
• 出版年：2016
• 出版时间：February 15, 2016
• 年：2016
• 卷：55
• 期：4
• 页码：1486-1496
• 全文大小：659K
• ISSN：1520-510X

文摘

Three novel bioactive silver–organic networks, namely, the 2D polymer [Ag(μ₃-PTA)(chc)]_n·n(Hchc)·2nH₂O (1), the 3D bioMOF [Ag₂(μ₃-PTA)₂(μ₂-chdc)]_n·5nH₂O (2), and the 2D polymer [Ag₂(μ₂-PTA)₂(μ₄-H₂chtc)]_n·6nH₂O (3), were constructed from 1,3,5-triaza-7-phosphaadamantane (PTA) and various flexible cyclohexanecarboxylic acids as building blocks {cyclohexanecarboxylic (Hchc), 1,4-cyclohexanedicarboxylic (H₂chdc), and 1,2,4,5-cyclohexanetetracarboxylic (H₄chtc) acid, respectively}. The obtained products 1–3 were fully characterized by IR and NMR spectroscopy, ESI-MS(±) spectrometry, elemental and thermogravimetric (TGA) analyses, and single-crystal and powder X-ray diffraction. Their structural diversity originates from distinct coordination modes of cyclohexanecarboxylate moieties as well as from the presence of unconventional N,N,P-tridentate or N,P-bidentate PTA spacers. Topological classification of underlying metal–organic networks was performed, disclosing the hcb, 4,4L28, and a rare fsc-3,4-Pbcn-3 topology in 1, 2, and 3, respectively. Moreover, combination of aqueous solubility (S_25°C ≈ 4–6 mg mL^–1), air stability, and appropriate coordination environments around silver centers favors a release of bioactive Ag⁺ ions by 1–3, which thus act as potent antibacterial and antifungal agents against Gram-positive (S. aureus) and Gram-negative (E. coli and P. aeruginosa) bacteria as well as a yeast (C. albicans). The best normalized minimum inhibitory concentrations (normalized MIC) of 10–18 (for bacterial strains) or 57 nmol mL^–1 (for a yeast strain) were achieved. Detailed ESI-MS studies were performed, confirming the relative stability of 1–3 in solution and giving additional insight on the self-assembly formation of polycarboxylate Ag–PTA derivatives and their crystal growth process.