Silver(I) 1,3,5-Triaza-7-phosphaadamantane Coordination Polymers Driven by Substituted Glutarate and Malonate Building Blocks: Self-Assembly Synthesis, Structural Features, and Antimicrobial Properties

Three new bioactive silver­(I) coordination polymers formulated as [Ag₂(μ₂-PTA)­(μ₃-PTA)­(μ₂-pga)­(H₂O)]_<i>n</i>·6H₂O (<b>1</b>), [Ag₂(μ₂-PTA)­(μ₃-PTA)<i>(</i>Hpmal)₂]<i><i>_n</i></i>·2H₂O (<b>2</b>), and [Ag­(μ₃-PTA) (Hdmga)]<i>_n</i> (<b>3</b>) were self-assembled from Ag₂O, 1,3,5-triaza-7-phosphaadamantane (PTA), and a substituted dicarboxylic acid (3-phenylglutaric acid (H₂pga), phenylmalonic acid (H₂pmal), or 3,3-dimethylglutaric acid (H₂dmga)) as an ancillary ligand. Compounds <b>1</b>–<b>3</b> were fully characterized by IR and NMR spectroscopy, ESI-MS(±), elemental analysis, and single-crystal X-ray diffraction, revealing that their architectural and topological diversity is governed by structural modulation of a dicarboxylate building block. The structures vary from a 1D cyclic chain with the SP 1-periodic net (4,4)­(0,2) topology in <b>2</b> to distinct 2D metal–organic layers with the <b>cem-d</b> and <b>hcb</b> topologies in <b>1</b> and <b>3</b>, respectively. In addition, compounds <b>1</b>–<b>3</b> exhibit a notable antimicrobial efficiency against a panel of common Gram-negative (E. coli and P. aeruginosa) and Gram-positive (S. aureus) bacteria and yeast (C. albicans). The best normalized minimum inhibitory concentrations (normalized MIC) of 11–23 nmol mL^–1 (for bacterial strains) or 68 nmol mL^–1 (for a yeast strain) are shown by compound <b>2</b>, and the eventual structure–bioactivity correlations are discussed

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

Three novel bioactive silver–organic networks, namely, the 2D polymer [Ag­(μ₃-PTA)­(chc)]_<i>n</i>·<i>n</i>(Hchc)·2<i>n</i>H₂O (<b>1</b>), the 3D bioMOF [Ag₂(μ₃-PTA)₂(μ₂-chdc)]_<i>n</i>·5nH₂O (<b>2</b>), and the 2D polymer [Ag₂(μ₂-PTA)₂(μ₄-H₂chtc)]_<i>n</i>·6<i>n</i>H₂O (<b>3</b>), 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 <b>1</b>–<b>3</b> 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 <i>N,N,P</i>-tridentate or <i>N,P</i>-bidentate PTA spacers. Topological classification of underlying metal–organic networks was performed, disclosing the <b>hcb</b>, <b>4,4L28</b>, and a rare <b>fsc-3,4-<i>Pbcn</i>-3</b> topology in <b>1</b>, <b>2</b>, and <b>3</b>, respectively. Moreover, combination of aqueous solubility (<i>S</i>_25°C ≈ 4–6 mg mL^–1), air stability, and appropriate coordination environments around silver centers favors a release of bioactive Ag⁺ ions by <b>1</b>–<b>3</b>, which thus act as potent antibacterial and antifungal agents against Gram-positive (<i>S. aureus</i>) and Gram-negative (<i>E. coli</i> and <i>P. aeruginosa</i>) bacteria as well as a yeast (<i>C. albicans</i>). 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 <b>1</b>–<b>3</b> in solution and giving additional insight on the self-assembly formation of polycarboxylate Ag–PTA derivatives and their crystal growth process