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 (S25°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.

The present work describes the facile synthesis, full characterization, and architectural diversity of three new bioactive silver-organic networks, namely 1D 2), and 3D [Ag 2 (μ 4 -PTA)(μ 4 -mal)] n (3) coordination polymers, generated via a mixed-ligand strategy using PTA (1,3,5-triaza-7-phosphaadamantane) as a main building block and flexible aliphatic dicarboxylic acids (succinic (H 2 suc), adipic (H 2 adip), or malonic (H 2 mal) acids) as an ancillary ligand source. The compounds 1−3 were isolated as moderately air and light stable crystalline solids and were fully characterized by IR and 1 H and 31 P{ 1 H} NMR spectroscopy, elemental analysis, ESI(±)-MS spectrometry, and single-crystal X-ray crystallography. The type of aliphatic dicarboxylate plays a key role in defining the dimensionality and structural and topological features of the resulting networks, which are also driven by the PTA blocks that adopt unconventional N,P-or N 3 ,P-coordination modes. The topological analysis of simplified underlying nets revealed that 1 possesses uninodal 3-connected chains with the SP 1-periodic net (4,4)(0,2) topology, 2 features a uninodal 4-connected layer with the skl topology, and 3 reveals a uninodal 4-connected metal−organic framework with the dia topology. The presence of the crystallization water molecules in polymers 1 and 2 gives rise to the extension of their metal−organic structures into 3D (1) or 2D (2) H-bonded networks that disclose rather rare topologies. All of the obtained silver(I) coordination polymers feature solubility in water (S 25 °C ≈ 3−5 mg mL −1 ) and show significant antibacterial and antifungal activity against the selected strains of Gram-negative (Escherichia coli, Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) bacteria and yeast (Candida albicans).

Three new bioactive silver(I) coordination polymers formulated as [Ag2(μ2-PTA)(μ3-PTA)(μ2-pga)(H2O)]n·6H2O (1), [Ag2(μ2-PTA)(μ3-PTA)(Hpmal)2]n·2H2O (2), and [Ag(μ3-PTA) (Hdmga)]n (3) 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 1-3 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 2 to distinct 2D metal-organic layers with the cem-d and hcb topologies in 1 and 3, respectively. In addition, compounds 1-3 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 2, and the eventual structure-bioactivity correlations are discussed.

The new series of silver(I) coordination polymers [Ag(N-N)(μ-PTA)]n(X)n (1, 2, 4-8, 10, 11) and discrete monomers [Ag(N-N)(PTA)2](X) (3, 9) {N-N = bpy (1-3), dtbpy (4), neocup (5, 6), phen (7-9), dione (10, 11); X = NO3 (1, 3, 5, 7, 9, 10), PF6 (2, 4, 6, 8, 11)} were generated by self-assembly reactions, in MeOH at ~25 °C, of AgNO3 or AgPF6 with 1,3,5-triaza-7-phosphaadamantane (PTA) and the corresponding polypyridines, namely 2,2'-bipyridine (bpy), 4,4'-di-tert-butyl-2,2'-bipyridine (dtbpy), 1,10-phenanthroline (phen), 2,9-dimethyl-1,10-phenanthroline (neocup) and 1,10-phenanthroline-5,6-dione (dione). The compounds were obtained as air and light stable solids and characterized by IR, (1)H and (31)P{(1)H} NMR spectroscopy, ESI(+)-MS and elemental analyses. The crystal structure of 1 was determined by single crystal X-ray diffraction analysis, revealing infinite one-dimensional (1D) linear chains driven by μ-PTA N,P-linkers. Apart from representing the first examples of the metal-PTA derivatives bearing polypyridine ligands, 1-11 also feature solubility in water (S(25°C) ≈ 4-18 mg mL(-1)). Selected compounds (1, 3, 5, 7, 9 and 10) were thus tested for their biological properties and found to exhibit significant antibacterial and antifungal activities, screened in vitro against the standard strains of Staphylococcus aureus, Staphylococcus pyogenes, Staphylococcus pneumoniae, Staphylococcus sanguinis, Staphylococcus mutans, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli and Candida albicans. Furthermore, the compounds 5, 7, 9 and 10 show a pronounced antiproliferative activity against human malignant melanoma (A375), and the effects on the inhibition of tumor cells in vitro are in agreement with the DNA-binding studies.

Two new bioactive silver-organic frameworks [Ag(m 3 -PTALS)] n (NO 3 ) n ?nH 2 O (1) and [Ag 4 (m 4 -PTALS)(m 5 -PTALS)(m 2 -SO 4 ) 2 (H 2 O) 2 ] n ?2nH 2 O (2) were easily assembled, thus opening up the application of PTALS as a versatile N,S-building block in the crystal engineering of MOFs. The obtained products reveal infinite 3D networks driven by multiply bridging PTALS spacers that adopt unprecedented N 2 S-coordination modes. The topological analysis of 1 discloses an uninodal 3-connected net with the srs (SrSi 2 ) topology, whereas 2 features a pentanodal 3,4,5-connected net with a hitherto undocumented topology. Apart from representing the first MOFs derived from PTALS, the compounds 1 and 2 display notable antibacterial and antifungal activities.