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Bacterial infections pose a serious threat to human health and socioeconomics worldwide. In the post-antibiotic era, the development of novel antimicrobial agents remains a challenge. Polyphenols are natural compounds with a variety of biological activities such as intrinsic antimicrobial activity and antioxidant properties. Metal-polyphenol obtained by chelation of polyphenol ligands with metal ions not only possesses efficient antimicrobial activity but also excellent biocompatibility, which has great potential for application in biomedical and food packaging fields. Herein, we developed metal-polyphenol coordination nanosheets named copper oxidized tannic acid quinone (CuTAQ) possessing efficient antibacterial and anti-biofilm effects, which was synthesized by a facile one-pot method. The synthesis was achieved by chelation of partially oxidized tannic acid (TA) with Cu2+ under mild conditions, which supports low-cost and large-scale production. It was demonstrated that CuTAQ exhibited high antibacterial activity via disrupting the integrity of bacterial cell membranes, inducing oxidative stress, and interfering with metabolism. In addition, CuTAQ exhibits excellent peroxidase catalytic activity and photothermal conversion properties, which play a significant role in enhancing its bactericidal and biofilm scavenging abilities. This study provides insights for rational design of innovative metal-polyphenol nanomaterials with efficient antimicrobial properties. • Metal-polyphenol nanosheets (CuTAQ) were prepared by a facile one-pot method. • CuTAQ possesses excellent peroxidase-like and photothermal properties. • CuTAQ significantly killed bacteria and eradicated biofilms at low concentrations. • The antibacterial mechanisms of CuTAQ against bacteria were explored. [ABSTRACT FROM AUTHOR]

Reactions of piperazine hexahydrate with triazol and paraformaldehyde afford a new piperazine-containing ligand: (N,N′-bis(1-H-1,2,4-triazole-1-yl)piperazine) (btp). X-ray crystal diffraction reveals that btp is an overall linear structure. Its Hg2+ polymer displays a zigzag chain in which piperazine is held in the chair conformation. In addition, the spectra properties of the btp and 1 are investigated, the strong luminescence characteristics of btp and 1 are found. [ABSTRACT FROM AUTHOR]

A new coordination polymer based on Group IB metal thiocyanates, [Ag (NCS)(dpds)] ( 1) (dpds = 2,2′-dipyridyldisulfide), has been synthesized by the pre-assembly method and characterized by X-ray crystallography. In 1, the Ag center adopts tetrahedral coordination geometry and the 2-D undulated layers of (4, 4) topology network is formed by dpds ligand with zigzag NCSAg chains. Graphical Abstract: A new coordination polymer based on Group IB metal thiocyanates, [Ag (NCS)(dpds)] ( 1) (dpds = 2,2′-dipyridyldisulfide), has been synthesized by the pre-assembly method and characterized by X-ray crystallography. In 1, the Ag center adopts tetrahedral coordination geometry and the 2-D undulated layers of (4, 4) topology network is formed by dpds ligand with zigzag NCSAg chains.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A coordination polymer, [Cu2(SCN)4(BPX)]n(BPX = 1,4-bis(pyridinium) xylol) was synthesized and characterized by IR spectrum, fluorescence spectrum and single crystal X-ray diffraction. Crystal structure revealed that the title compound crystallized in monoclinic system with space group P2(1)/c, a = 5.7540(7)Å, b = 12.7203(15) Å, c = 17.598(2) Å, β = 94.9940(10)°. Two SCN-ions served as bridging ligands to link two Cu(I) ions, giving rise to an eight-member ring. Furthermore, copper atom and sulfur atom of the eight-member ring bonded sulfur atom and copper atom of adjacent eight-member ring through the formation of Cu-S to form a small four-member ring. Thus, innumerable eight-member rings alternately linked four-member rings each other to form an infinite one-dimensional ladder-shaped structure. [ABSTRACT FROM AUTHOR]

Seven new metal-organic coordination polymers, [M(tzda)(H2O)4]n [M = Co(1), Ni (2) and Zn(3)], [Zn(tzda)(4,4'-bipy)]n (4), [Cd(tzda)(4,4'-bipy)0.5(H2O)]n (5) and [M(tzda)(4,4'-bipy)(H2O)]n [M = Co(6), Ni(7)] [H2tzda = (1,3,4-thiadiazole-2,5-diyldithio)diacetic acid, 4,4'-bipy = 4,4'-bipyridine] have been hydrothermally synthesized and structurally characterized by X-ray single crystal diffraction. Compounds 1-3 display similar 1D zigzag chain structure. Compound 4 possesses a 2D-layered architecture generated from [Zn(tzda)]n moiety with double-chain structure cross-linking 4,4'-bipy spacers, while compound 5 consists of -Cd-OCO-Cd-OCO- chains cross-linked through -CH2SC2N2SSCH2- spacers of tzda anions and 4,4'-bipy, also showing a 2D-layered structure. The structures of 6 and 7 seem more complicated, in which the [M(tzda)]n layered subunits are extended to unique 3D framework by the bridging 4,4'-bipy ligand. Photoluminescence investigations reveal that 4 and 5 both display strong blue emissions in the solid state at room temperature, which could be significant in the field of luminescent materials. The magnetic studies of 6 and 7 show both display the characteristics of a weak antiferromagnetic coupling between metal ions in the system mediated by carboxylate bridges. [ABSTRACT FROM AUTHOR]

Hydrothermal reactions of Mn(II), Co(II), Cu(II), andCd(II) salts with 2-((1H-1,2,4-triazol-1-yl)methyl)-1H-imidazole-4,5-dicarboxylic acid (H3tmidc) leadto four novel coordination polymers, namely, [Mn3(tmidc)2(H2O)4]·(H2O)6(1), [Co3(tmidc)2(H2O)4]·(H2O)4(2), [Cu3(tmidc)2(H2O)]·(H2O) (3), and [Cd(Htmidc)] (4). Compound 1has a three-dimensional (3D) architecture, and the topologicalstudy shows that its framework features a 3D (3,4)-connected fsc-3,4-Pbcanetwork with the Schläfli topological symbolof (63)(63.83). Compound 2exhibits a 3D pillared framework constructed by 4-fold one-dimensional(1D) helical chains and possesses open helical channels in the framework.Topological analysis reveals that it is a unique (3,4)-connected netwith the Schläfli symbol of (4.52)(4.5.114) which is not enumerated in RCSR andTOPOS, and has not been reportedin the literature. Compound 3features a 3D intricateframework displaying a new (3,4)-connected 4-nodal net with the Schläflisymbol of (5.72)(4.5.7)(52.72.8.10)(4.5.73.8) which has not been observed in any other coordinationpolymers. Topological analysis of the 3D network found in compound 4reveals that the whole structure can be rationalized asa (4.65)(4.65) crbtopologicalnet. [ABSTRACT FROM AUTHOR]

Abstract: Five new transition metal coordination polymers based on H2tzda and co-ligand bpe, {[M(tzda)(bpe)]·H2O} n [M=Zn(1), Cd(2), Mn(3), Co(4)] and [Ni2(tzda)2(bpe)2(H2O)] n (5) [H2tzda=(1,3,4-thiadiazole-2,5-diyldithio)diacetic acid, bpe=1,2-bis(4-pyridyl)ethane], have been hydrothermally synthesized and structurally characterized. Compounds 1–4 feature a 2D-layered architecture generated from [M(tzda)] n moiety with double-chain structure cross-linking bpe spacers. However, the conformations bpe adopts in 3 and 4 are different from those in 1 and 2 due to the rotation of C–C single bond in bpe. Polymer 5 exhibits an interesting 3D porous framework with 2-fold interpenetration, in which intriguing 1D double helix chains are observed. The photoluminescence properties of 1 and 2 in the solid-state at room temperature are investigated. In addition, variable-temperature magnetic data show weak antiferromagnetic behavior in 3–5. [Copyright &y& Elsevier]

Abstract: Three new d 10 coordination polymers, namely [Cd(taa)Cl] n 1, [Hg(taa)Cl] n 2, and [Ag1.5(taa)(NO3)0.5] n 3 (taa=1H-1,2,4-triazole-1-acatate anion) have been prepared and characterized by elemental analysis, IR, and single crystal X-ray diffraction. Compound 1 consists of two-dimensional layers constructed by carboxyl-linked helical chains, which are further linked through carboxyl group to generate a unique 3D open framework. Topological analysis reveals that the structure of 1 can be classified as an unprecedented (3,8)-connected network with the Schläfli symbol (4.52)2(42.58.614.73.8). Compound 2 manifests a doubly interpenetrated decorated α-polonium cubic network with the Schläfli symbol of (410.62.83). Compound 3 consists of 2D puckered layers made up of Ag centers and taa− bridges. In addition, all of these compounds are photoluminescent in the solid state with spectra that closely resemble those of the ligand precursor. [Copyright &y& Elsevier]

Three Cd(II) coordination polymers, namely, {[Cd 2 (bptp) 2 (H 2 O) 4 ]·3H 2 O} n ( 1 ), {[Cd 2 (Hbptp)(BTC)(H 2 O)]·4H 2 O} n ( 2 ) and {[Cd 2 (H 2 bptp)(BTEC)]·H 2 O} n ( 3 ) (1,3,5-H 3 BTC = 1,3,5-benzenetricarboxylic acid and H 4 BTEC = 1,2,4,5-benzenetetracarboxylic acid), have been successfully isolated by employing the rigid N-heterocyclic ligand 2,6-bis(3-(pyrid-3-yl)-1,2,4-triazolyl)pyridine (H 2 bptp) and different aromatic polycarboxylates. Complex 1 performs a helical chain structure, which is extended into 3D supermolecular framework due to its strong hydrogen bonding interactions. 2 demonstrates a binodal 3,4-connected 2D grid with the point symbol of (4 2 ·6 2 ·8)(4 2 ·6), while complex 3 features an interesting 2D structure with its 1D double chain looking like a folded paper lantern. The optical band gaps were analyzed by diffuse-reflectance UV–Vis spectra. The photocatalytic experiments for these complexes reflect well on their activities for the decomposition of MB under the irradiation of high-pressure mercury lamp. Complexes 1 and 2 present extremely good photocatalytic properties with their photocatalytic activities increasing from 17% (without any catalyst) to 87% for 1 and 96% for 2 after 2 h of irradiation. In addition, the luminescent properties of 1 – 3 have also been investigated. [ABSTRACT FROM AUTHOR]

Abstract: Four novel lanthanide(III) coordination polymers [Ln(L)1.5(H2O)2]·5H2O [Ln=Sm (1), Eu (2), Tb (3), Dy (4)] have been hydrothermally synthesized by the reaction of 1,2-bis[4-amino-5-carboxylmethylthio-(1,2,4-triazol-3-yl)]ethane (H2L) with lanthanide(III) salts, and structurally characterized by single crystal X-ray diffraction. Polymers 1–4 are isostructural, in which all the LnIII atoms are nine-coordinated and the carboxylate groups adopt three different coordination modes (bidentate chelate, bidentate bridging, bidentate chelate bridging) to connect LnIII atoms. These polymers exhibit 3D network structures with 2-fold interpenetration, in which intriguing 1D channels are observed. Besides, the spectra properties of the title polymers are investigated, the strong luminescence characteristics of 2–3 are found. [Copyright &y& Elsevier]

Abstract: Four novel coordination polymers, one-dimensional chains [M(PTE)2(N3)2] n (M=Mn for 1 and Co for 2), and two-dimensional layers [M(PTE)2(dca)2] n (M=Mn for 3 and Co for 4) (PTE=1-(2,4-difluorophenyl-2-(1H-1,2,4-triazol-1-yl)ethanone, dca=dicyanamide anion, N(CN)2 −), have been synthesized under mild ambient conditions and structurally characterized by single crystal X-ray diffraction. In all four crystal structures, the metal atoms adopt octahedral coordination geometry with six nitrogen atoms from two monodentate PTE ligands and four azido (or dca) bridging ligands. The crystal structures of 1 and 2 are isostructural 1-D polymeric chains, alternatively linked by double end-on and double end-to-end azido bridges. However, the bent dca ligands as bidentate μ2-1,5 bridging ligands interlink the octahedral metal units to lead to 2-D (4,4) grid networks in 3 and 4. Temperature-dependent magnetic measurements in 2–300K have been performed for these four polymers, and suggest alternative ferro- and antiferromagnetic couplings for end-on and end-to-end azido bridges in 1, and the dominant ferromagnetic coupling in 2, respectively. Both polymers 3 and 4 show weak antiferromagnetic exchanges through the μ2-1,5-dca bridges. The effects of auxiliary coligands on the structure and the nature of these magnetic exchanges are discussed in the light of the crystal structures in detail. [Copyright &y& Elsevier]

Compounds [Co(NO3)2(bpt)2·2CH3OH]n (1) and [Mn(NCS)2(bpt)3·H2O]n (2) (bpt=N,N′-bis(3-pyridylmethyl)thiourea) have been synthesized and characterized structurally. Two bpt ligands coordinate simultaneously to two cobalt(II) centers to generate the double helical one-dimensional chain [Co(NO3)2(bpt)2]n. Intermolecular hydrogen-bonding arising from the interaction of thiourea units of bpt with NO3 − ions or solvent molecular forms a three-dimensional supramolecule in the solid structure (polymer 1). Bpt ligands (polymer 2) acting as bridges connect to two manganese(II) centers lead to the one-dimensional linear chain [Mn(NCS)2(bpt)3]n. The two-dimensional network was formed by O⋯H&z.sbnd;N, S⋯H&z.sbnd;O and OH⋯SCN hydrogen bonds. The determination of variable-temperature magnetic susceptibilities (5–300 K) of the two compounds shows that the magnetic behavior obeys the Curie–Weiss law. [Copyright &y& Elsevier]