Ag Interactions Research Articles

Single-Step Substitution of all the α, β-Positions in Pyrrole: Choice of Binuclear versus Multinuclear Complex of the Novel Polydentate Ligand

The α and β-positions of pyrrole were substituted with 3,5-dimethylpyrazolylmethyl groups in a single step that involved the reaction between 2,5-dimethylaminomethylpyrrole and 3,5-dimethylpyrazole-1-carbinol, affording 2,3,4,5-tetrakis(3,5-dimethylpyrazol-1-ylmethyl)pyrrole LH in 40% yield. The coordination chemistry of this new polydentate ligand LH was explored by synthesizing several Pd(II), Cu(I), and Ag(I) complexes. When LH was used as a neutral ligand with [Pd(COD)Cl2], AgBF4, and CuX (X = Cl and I), compartmental type binuclear Pd(II) and Ag(I) complexes such as [Pd2Cl4(μ-C4HN-2,3,4,5-(CH2Me2pz)4-N,N,N,N)] and [Ag2(μ-C4HN-2,3,4,5-(CH2Me2pz)4-N,N,N,N)(CH3CN)2](2+)[BF4(-)]2 and cage-like copper(I) complexes [Cu2(μ-X)(μ-C4HN-2,3,4,5-(CH2Me2pz)4-N,N,N,N)](+)[CuX2](-) (X = Cl and I) containing a halide ion bridging in a bent fashion were obtained, respectively. Conversely, when the same metal precursors were treated with LH in the presence of n-BuLi, the multinuclear complexes [Pd2Cl3(μ-C4N-2,3,4,5-(CH2Me2pz)4-N,N,N,N,N)], [(Cu2(μ-I){μ-C4N-2,3,4,5-(CH2Me2pz)4-N,N,N,N,N})2Cu](+)I(-), and [Ag4(μ-C4N-2,3,4,5-(CH2Me2pz)4-N,N,N,N)2](2+)[BF4(-)]2 were obtained. In addition, the treatment of LH with [Pd(OAc)2] gave the mononuclear complex, [Pd(OAc)(C4N-2,3,4,5-(CH2Me2pz)4-N,N,N)]. The chloride analogue of this complex was obtained by the reaction of LH with [Pd(COD)Cl2] in the presence of triethylamine. The structures of all complexes were determined by single-crystal X-ray diffraction analyses, which revealed interesting structural features, including pyrazole arms adopting different conformations with respect to the pyrrole ring plane and linear two- and three-coordinated copper(I) and silver(I) atoms exhibiting weak interactions between the metal and the pyrrolic carbon atoms and Ag(I)···Ag(I) interactions. The observed shorter metal pyrrolide nitrogen (M-N) bond distances and the elongation of the C-C double and single bond distances of the pyrrole ring in these complexes probably indicates the presence of π-donation/π-back bonding between the metal and the pyrrole ring. These multinuclear complexes are novel, and their formations are favored by the multidentating nature of the ligand LH.

Syntheses, characterizations, thermal stability and photoluminescence of four silver coordination polymers with mixed ligands

Four silver(I) coordination polymers (CPs), namely, [Ag2(mpyz)(ipa)]n (1) [Ag3(mpyz)(btc)]n (2) [Ag4(apyz)2(ipa)·0.5 DMF]n (3) [Ag3(apyz)2(btc)]n (4), have been purposefully synthesized under ultrasonic treatment of methylpyrazine (mpyz), aminopyrazine (apyz), isophthalic acid (H2ipa), 1,3,5-benzenetricarboxylic acid (H3btc) and AgNO3. And they were characterized by elemental analysis and X-ray single-crystal diffraction. Complexes 1 and 2 based on the same auxiliary ligand mpyz show various structures with silver chain. Complex 1 features a three-dimensional (3D) structure which consists of 1D helical silver chains. Complex 2 possesses an infinite silver chain with repeated Ag-triangle units. Complexes 3 and 4 with apyz as auxiliary ligand exhibit different structures. Complex 3 exhibits a 2D 44-sql network with the 1D double chains and complex 4 shows Ag6 units which are connected by Ag⋯Ag interaction in the 3D coordination network. Effects of the aromatic polycarboxylates on the structures and the intricacy of the self-assembly process were discussed. Additionally, results about infrared spectroscopy (IR), thermogravimetric analyses (TGA) and photoluminescence spectra behaviours of the compounds were also discussed.

Antibacterial mechanisms of silica/polydopamine/silver nanoparticles against gram positive and gram negative bacteria

Silica/polydopamine/silver (SiO2/PD/Ag) nanoparticles (NPs) with a core–shell–satellite structure were fabricated and the mechanisms of their antibacterial activity were investigated. In this reported work, the results of the reactive oxygen species (ROS) assays, the deoxyribonucleic acid (DNA) damage assays and a cell morphology observation confirmed that Vibrio natriegens, a gram negative bacterium and Bacillus subtilis, a gram positive bacterium could be inhibited by the NPs. Gram negative bacteria exhibited more sensitivity towards the Ag NPs because these NPs were associated with penetration into the cytoplasm, with the subsequent local interaction of Ag with the cell components; thus, causing damages to the cells. SiO2/PD/Ag NPs produced ROS which caused damage to the DNA leading to the suppression of transcription as detected by a reporter gene assay. Furthermore, ROS induced membrane damage was determined by transmission electron microscopy. Thus, the mechanisms of antibacterial activity were interpreted more precisely by using the aforementioned experiments. The results revealed that the production of ROS and damage to the membrane were the two major mechanisms of the bactericidal action of SiO2/PD/Ag NPs; thus, these NPs could be employed as effective antifouling agents.

Metallophilic interactions in polynuclear Ag(I) complex with 1-methylhydantoin studied by X-ray absorption, electronic and vibrational spectroscopies

Argentophilic interaction has been studied in silver methylhydantoin complex {[Ag(1-methylhydantoin)]·0.5H2O}n using electronic, Raman and X-ray absorption spectroscopies strengthened theoretically. The EXAFS confirmed coordination number (CN=3) of complex and metalophilic interactions. The digital filter analysis of electronic spectra revealed that broad bands at ca 38000cm−1 and ca 45000cm−1 observed in the solid state and solutions, respectively, were composed of two transitions, namely L–L(π→π∗) and Ag–Ag tentatively assigned to (4dσ∗→5pσ) in silver ion. The Raman spectroscopy data showed a new band at 83cm−1 assigned to ν(Ag2) vibration theoretically supported by DFT.

Exploration of heterometallic systems containing silver(I) in acyclic Schiff base ligands: Finite and infinite self-assemblies as a result of silver(I)–carbon bond and silver(I)⋯silver(I) interaction

The work in this report describes the syntheses and crystal structures of nine copper(II)–silver(I) compounds derived from some single-compartment N(imine)2O(phenoxo)2 or double-compartment N(imine)2O(phenoxo)2–O(phenoxo)2O(methoxy/ethoxy)2 acyclic Schiff base ligands. The nine compounds are [{CuII(ClO4)Lsal–enAgI}2{CuII(ClO4)Lsal–enAgI(H2O)}]n (1), [CuIILsal–pnAgI(ClO4)]n (2), [{CuIILsal–pnAgI(NO3)}2] (3), [(CuIILacpn–en)2AgI(MeCN)2](ClO4) (4), [{CuIILOMe–enAgI(NO3)}2] (5), [{CuIILOMe–pnAgI(NO3)}2] (6), [{CuIILOMe–pnAgI(NO3)}2]·2H2O (7), [{CuIILOEt–enAgI(NO3)}2] (8) and [{CuIILOEt–opAgI(MeOH)}2](ClO4)2 (9), where the superscripts in the ligand symbols mean the following: (i) sal, acpn, OMe and OEt indicate that the aldehyde counterpart is salicylaldehyde, 2-hydroxyacetophenone, 3-methoxysalicylaldehyde and 3-ethoxysalicylaldehyde, respectively; (ii) en, pn and op indicate that the diamine counterpart is ethylenediamine, 1,3-diaminopropane and o-phenylenediamine, respectively. Copper(II) in all these compounds occupies a N2O2 compartment and the two phenoxo oxygen atoms in all cases bridge one copper(II) and one silver(I) centers. Compound 4 is a trinuclear CuIIAgICuII system. Compounds 3 and 5–9 are dimer-of-dinuclear compounds, in which the dimerization takes place due to interdinuclear Cu–O(nitrate) and Ag⋯Ag interactions in 3, 5 and 6 and due to Ag–π (η1-/η2-) bonds in 7–9. Compounds 2 and 1 are one-dimensional coordination polymers due to Ag–π (η2-)/Ag–π (η3-) bonds. CSD search/analysis reveals some definite significant aspects in both the Ag–π and Ag⋯Ag bonded systems in the present investigation.

Adsorptive separation of dimethyl disulfide from liquefied petroleum gas by different zeolites and selectivity study via FT-IR

The removal of dimethyl disulfide from model liquefied petroleum gas using metal salt impregnated zeolite as the adsorbent was studied in a fixed-bed adsorption equipment. Effects of different carrier, metal iron species and content of active component, mass space velocity, temperature, as well as adsorption selectivity and regeneration performance were all investigated by performing the breakthrough experiment. Among all these adsorbents, 5wt.%Ag2O/NaY showed the highest breakthrough sulfur capacity. The adsorption selectivity of Ag2O/NaY was studied by the infrared spectra. It was found that the direct S–Ag(I) interaction was the essential reason for the evidently improved adsorption ability and selectivity of Ag2O/NaY for removing disulfide from solutions containing olefin. Regeneration study indicated that the saturated adsorbent was regenerated under the temperature of 550°C for 8h in the air atmosphere. After five times regeneration, the adsorbent Ag2O/NaY still shows high breakthrough sulfur capacity.

Contact interaction of the Bi12GeO20, Bi12SiO20, and Bi4Ge3O12 melts with noble metals

The sessile drop method is used to study the contact interaction of Ag, Au, Pd, Pt, and Ir with the Bi2O3-GeO2 and Bi2O3-SiO2 melts. These melts spread over Ag and Pd and, in some cases, over Au and Pt at a rather high speed and form equilibrium contact angles on Ir.

Effect of different carboxylates on two Ag(I) coordination polymers with 2,5-dimethylpyrazine ligand

Two new metal–organic framework namely, [Ag3(dmpyz)1.5(btc)]n (1), and [Ag2(dmpyz)(pta)]n (2), have been synthesized and structurally characterized. Compound 1 is a 3D structure incorporating μ5-(η1,η1):(η1,η1):(η1,η1) btc and μ2-N1,N1,μ2-N2,N3 dmpyz ligands. In compound 2, the μ5-η1:η2:η3:η1 pta and the dmpyz ligands link the [Ag4O2] units into a 2D structure. It is noteworthy that the Ag⋯Ag interactions were observed in the two coordination polymers. The results show that the structural diversity of the polymers is mainly attributed to the usage of diverse ancillary carboxylate ligands. The thermal stabilities and photoluminescence behaviors were addressed.

Investigation of thermal behavior of graphite-supported Ag nanoclusters of different sizes using molecular dynamics simulations

Thermal behaviors of Ag nanoclusters with 38, 108 and 256 atoms supported on static graphite bilayer substrate were investigated using molecular dynamics (MD) simulations. The many body quantum Sutton–Chen (QSC) potential was used to describe the Ag–Ag interactions, also, the Lennard–Jones (LJ) 12–6 potential was applied for Ag–graphite interactions. Nanoclusters were simulated for heating and cooling in the range of 100–1700K in the canonical ensemble. The potential energy, specific heat capacity, density profile, deformation parameter and self-diffusion coefficient were calculated at different temperatures. Results show that melting temperatures are higher than that for free Ag nanoclusters of similar size and structure. Comparison of the potential curves in heating and cooling for three nanoclusters show that the hysteresis decreases when the cluster size decreases. Also, irreversibility of the structural changes relative to temperature, Flattening of nanocluster on the graphite surface and wetting were observed using the density profiles and deformation parameters.

Multinuclear coordination polymers based on Ag⋯Ag interaction: syntheses, structures, and luminescence properties

A series of coordination polymers based on Ag⋯Ag interactions, namely, [Ag2(hpyb)0.5(L1)0.5(NO3)]·H2O (1), [Ag4(hpyb)(HL2)(NO3)2]·2H2O (2), [Ag3(hpyb)0.5(L3)(NO3)] (3), [Ag6(hpyb)(L4)2(NO3)]·NO3·2H2O (4), [Ag5(hpyb)0.5(L5)2(NO3)]·H2O (5), {Ag4(hpyb)[L6(CH3)2]2} (6), {Ag6(hpyb)(HL7)2[L7(CH3)]} (7) and [Ag3(hpyb)0.5(HL8)]·H2O (8) (H2L1 = p-phthalic acid, H3L2 = 1,2,3-benzenetricarboxylic acid, H2L3 = cis-2-butenedioic acid, H2L4 = 2,3-pyridinedicarboxylic acid, H2L5 = m-phthalic acid, H4L6 = 1,2,4,5-benzenetetracarboxylic acid, H3L7 = 1,2,4-benzenetricarboxylic acid and H4L8 = 4,4′-oxydiphthalic acid) has been synthesized. For compounds 1–4, the polycarboxylate anions bridge multinuclear Ag(I) units to form 1D chains, respectively. The chains are extended by π–π interactions into a 2D supramolecular layer for compound 3 and 3D supramolecular architectures for compounds 1, 2 and 4. Compound 5 displays a 3D (4,8)-connected (34·42)(34·412·58·64)2 framework. Compounds 6–8 exhibit 2D layers, where the layers of 6 and 8 are further linked by π–π interactions to yield 3D supramolecular architectures. In the solid state, compounds 1–8 exhibit strong fluorescence emission bands at room temperature.

Construction of a series of coordination polymers based on 1,4-naphthalenedicarboxylic and flexible dipyridyl ligands

Six new coordination polymers, {[Ag(bpa)]·(1,4-Hndc)}n (1), {[Ag(bpp)]·(1,4-Hndc)}n (2), [Cd(1,4-ndc)(bpa)0.5]n (3), [Cd2(1,4-ndc)2(bpp)]n (4), [Zn(1,4-ndc)(bpa)0.5]n (5) and [Co2(H2O)(1,4-ndc)2(bpp)]n (6), have been prepared under hydrothermal conditions (bpa = 1,2-bis(4-pyridyl)ethane, bpp = 1,3-bis(4-pyridyl)propane, 1,4-H2ndc = 1,4-naphthalenedicarboxylic). All these compounds were characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction and single crystal X-ray diffraction. 1 and 2 are 1D coordination polymers. They are further linked by hydrogen-bonding interactions or Ag⋯Ag and hydrogen-bonding interactions to form a 2D (4,4) or (6,3) supramolecular network, respectively. 3 and 4 are 3D (4,5)-connected frameworks with the same structural motif. 5 comprises a 3D pcu net, and the pcu net is interpenetrated by a crystallographic equivalent net to form a two-fold interpenetrating 3D architecture. 6 exhibits a 3D 12-connected net. Thermal stability and photoluminescent properties of 1–6 were also investigated.

Single Molecule Investigations of the Interaction of Ag+ with Single Cytosine, Methylcytosine and Hydroxymethylcytosine-Cytosine Mismatches in a Nanopore

Cytosine (C) modifications such as 5-methylcytosine (mC) and 5-hydroxymethylcytosine (hmC) are important epigenetic markers associated with gene expression 1 and tumorigenesis 2, 3. However, bisulfite conversion, the gold standard methodology for mC mapping can not distinguish mC and hmC bases. Recent studies have demonstrated hmC detection via peptide recognizing 4, enzymes 5, fluorescence 6 and hmC-specific antibodies 7, nevertheless, a method for directly discriminating C, mC and hmC bases without labeling, modification and amplification is still missing. Here we show that the DNA duplex containing single cytosine-cytosine (C-C), cytosine-methylcytosine (C-mC) and cytosine-hydroxymethylcytosine (C-hmC) mismatches can be discriminated by their interactions with Ag+ inside the alpha-hemolysin nanopore. Molecular dynamics simulations reveal that the paring of a C-C mismatch through hydrogen bond results in a binding site for cations, such as K+ and Ag+. Cytosine modifications such as mC and hmC disrupted both the hydrogen bonds, which subsequently disrupts Ag+ binding. As a result, these modifications can be distinguished in the nanopore by differences in the stability of DNA-Ag+ complexes.

Theoretical studies on an unusual [Ag]+⋯[Au]−⋯[Au]−⋯[Ag]+ metallophilic pattern: Dispersive forces vs. classical coulomb forces

We have studied theoretically the organometallic compound [{Au(C6Cl5)2}Ag([9]aneS3)]2, which displays an unprecedented [Ag]+–[Au]−–[Au]−–[Ag]+ sequence of metals, formed by unsupported Au(I)⋯Au(I) and Au(I)⋯Ag(I) interactions and weaker Cipso⋯Ag and C6Cl5⋯C6Cl5 π-stacking interactions. Density Functional Theory calculations using the pbe functional (DFT/pbe), Hartree–Fock (HF), and second-order Møller Plesset perturbation theory (MP2) calculations have been performed on five model systems based on the X-ray structure. Two dinuclear models (A1 and A2) have been used to estimate the BSSE-corrected interaction energy at HF and MP2 levels between one Ag(I) and one Au(I) fragment and permit to separate the Cipso⋯Ag(I) and Au(I)⋯Ag(I) contribution to the interaction. Three tetranuclear models (B1–B3) have been used to determine the Cipso⋯Ag(I), Au(I)⋯Ag(I), Au(I)⋯Au(I) and π-stacking interactions present in the molecule. The HF level accounts for the ionic component of the interactions and the MP2 level also account for the dispersive contribution; both permits to study the nature and strength of all different types of interactions present in the molecule.

First-principles calculations of Ag addition on the diffusion mechanisms of Cu–Fe alloys

The effect of Ag addition on the diffusion mechanisms of aging precipitation processed Cu–Fe alloys were investigated by first-principles calculations. The calculation of solute–solute binding energies accurately revealed an attractive binding for the Fe–Fe at the first NN site, and Ag–Ag at the first NN site as well as the second NN site, however the Fe–Ag interactions are repulsive both at the first NN and the second NN distance. The investigation of binding energy between X and V (X represents Fe or Ag and V a vacancy) showed that vacancy is more likely to be in the proximity of the solute Ag atom, and the addition of Ag to dilute Cu–Fe system will increase the local vacancy concentration close to a Ag–Fe dimer. The calculated migration energy for an X–V exchange indicated that the Ag atom diffused more easily in Cu than Fe atom; and the addition of Ag decreased the energy of the transition state, thereby significantly reduced the migration energy of Fe. The results agree well with the available experimental observation. The calculation gives way to find other suitable alloying elements for preparation of high strength and high conductivity Cu–Fe alloys or in situ composites.

Before and Beyond the Micellization of n-Alkyl Glycosides. A Water-1H NMR Relaxation Study

The interactions between the headgroups of n-alkyl glycoside (AG) and water molecules were studied by nuclear magnetic transverse relaxation times (T2) of the water protons before and beyond the micellization. Despite the low concentration of the surfactants (mM), their micellization induce strong effect on the T2 values of bulk water when the AG molecules self-aggregate into micelles. This is associated with the decreasing of the fraction of OH headgroups of AG to exchange protons with water molecules due to the OH headgroups intermolecular interactions of AG at the micelle surface. These findings support the computational results described in the literature, which indicate that the water hydrogen bonding to OH headgroups is perturbed at AG micelle surfaces.

Photochemical assisted formation of silver nano dendrites and their application in amperometric sensing of nitrite

Herein, we describe a photochemical route for the synthesis of silver (Ag) dendrites nanostructure using phenothiazine (PTZ) as a reductant as well as stabilizer without any extra control viz. surfactant, pH etc. This hybrid material derived from nanoscale silver capped with phenothiazine and its oxidation product (PTZH) has been explored for the development of a highly sensitive electro-sensor of nitrite ions. Further, a possible reaction mechanism for the formation of the silver dendrites nanostructure has also been proposed. The synthesized hybrid material (Ag–PTZH) has been characterized by UV-visible spectroscopy, cyclic voltammetry, transmission electron microscopy, field emission scanning electron microscopy and X-ray photoelectron spectroscopy. This hybrid material modified electrode efficiently catalyzes the electrochemical oxidation of nitrite at the potential of 0.44 V vs. AgCl/Ag and shows a linear response towards nitrite ion sensing with 2.43 μA μM−1 sensitivity and 2.3 nM limit of detection at a S/N (signal-to-noise ratio) of 3. The electrochemistry behind this sensing of nitrite is probably due to high connectivity throughout the silver dendrites nanostructure capped with phenothiazine and its oxidation product which exhibits high electron transfer kinetics via interaction of Ag–PTZH with oxygen atoms of NO2−.

Synthesis, Crystal Structure, Theoretical Study, Thermal ­Behavior, and Luminescence Property of A Bromide‐Bridged Silver(I) Complex with 4, 4′‐Bipyridine

Abstract The dinuclear silver(I) complex [{(PPh3)Ag(μ2‐Br)}2(μ2‐bpy)]n (1) (PPh3 = triphenylphosphine, bpy = 4, 4′‐bipyridine) was synthesized and characterized by elemental analysis, 1H NMR, MS, infrared spectroscopy, X‐ray single crystal analysis, thermogravimetric and fluorescent analysis. The complex crystallizes in the triclinic system with space group P$\bar{1}$ [a = 9.2012(18) Å, b = 9.6907(19) Å, c = 13.134(3) Å, α = 104.77(3)°, β = 109.41(3)°, γ = 92.57(3)°, V = 1057.2(4) Å3, Z = 2]. The central unit of complex 1 consists of a [Ag2Br2] core and the Ag···Ag distance in the [Ag2Br2] core is 3.102(2) Å, supporting the Ag···Ag interaction. Complex 1 exhibits an interesting one‐dimensional zigzag chain structure. Density functional theory and time‐dependent density functional theory calculations at the B3LYP/ LanL2DZ*+6‐31G* level were performed on 1 to rationalize its experimental absorption spectra. Fluorescent analysis reveals that complex 1 exhibits intense luminescence in ethanol solution at room temperature.

Interaction of metal nanoparticles with recombinant arginine kinase from Trypanosoma brucei: Thermodynamic and spectrofluorimetric evaluation

BackgroundTrypanosoma brucei, responsible for African sleeping sickness, is a lethal parasite against which there is need for new drug protocols. It is therefore relevant to attack possible biomedical targets with specific preparations and since arginine kinase does not occur in humans but is present in the parasite it becomes a suitable target. MethodsFluorescence quenching, thermodynamic analysis and FRET have shown that arginine kinase from T. brucei interacted with silver or gold nanoparticles. ResultsThe enzyme only had one binding site. At 25°C the dissociation (Kd) and Stern–Volmer constants (KSV) were 15.2nM, 0.058nM−1 [Ag]; and 43.5nM, 0.052nM−1 [Au] and these decreased to 11.2nM, 0.041nM−1 [Ag]; and 24.2nM, 0.039nM−1 [Au] at 30°C illustrating static quenching and the formation of a non-fluorescent fluorophore–nanoparticle complex. Silver nanoparticles bound to arginine kinase with greater affinity, enhanced fluorescence quenching and easier access to tryptophan molecules than gold. Negative ΔH and ΔG values implied that the interaction of both Ag and Au nanoparticles with arginine kinase was spontaneous with electrostatic forces. FRET confirmed that the nanoparticles were bound 2.11nm [Ag] and 2.26nm [Au] from a single surface tryptophan residue. ConclusionsThe nanoparticles bind close to the arginine substrate through a cysteine residue that controls the electrophilic and nucleophilic characters of the substrate arginine–guanidinium group crucial for enzymatic phosphoryl transfer between ADP and ATP. General significanceThe nanoparticles of silver and gold interact with arginine kinase from T. brucei and may prove to have far reaching consequences in clinical trials.

Synthesis, Characterization and Biological Evaluation of Two Silver(I) trans‐Cinnamate Complexes as Urease Inhibitors

AbstractTwo new silver(I) trans‐cinnamates, namely [Ag(2‐cca)(H2O)]2 (1) and [Ag(4‐cca)]n (2) (2‐ccaH = 2‐chlorocinnamic acid and 4‐ccaH = 4‐chlorocinnamic acid), were synthesized and structurally characterized. Single crystal X‐ray studies reveal that each silver(I) atom in 1 is two‐coordinate by a 2‐chlorocinnamate ligand and one water molecule to afford a discrete centrosymmetric dimer with the ligand‐unsupported Ag···Ag interactions (3.218(4) Å), while a pair of symmetry‐related silver(I) atoms in 2 are clamped by two μ2‐η1:η1 4‐chlorocinnamate ligands to yield a binuclear silver(I) moiety incorporating a ligand‐supported Ag···Ag interaction (2.819(5) Å). Both complexes 1 and 2 show potent urease inhibitory activities with the respective IC50 values of 0.66 and 1.10 μM.

Syntheses, structures and photoluminescent properties of three d10 coordination architectures based on in-situ 1,3,5-triazine derivatives

In the presence of aromatic carboxylic acids, three new d10 transition metal coordination polymers, [Ag(PAHT)]n(1), [Ag2(HCA)]n(2) and [Cu6(CA)2(H2O)]n(3) (HPAHT=2-phenyl-4-amino-6-hydroxy-1,3,5-triazine, H3CA=cyanuric acid) have been synthesized based on in-situ 1,3,5-triazine derivatives resulting from 2,4-diamino-6-phenyl-1,3,5-triazine, 2-chloro-4,6-diamino-1,3,5-triazine and melamine under hydrothermal conditions. Complexes 1–3 have been characterized by single-crystal X-ray diffraction, IR spectra, elemental analysis and thermogravimetric analysis (TGA). The compound 1 exhibits a uninodal three-connected 3D network with a rare lig LiGe type topology, which contains right-handed and left-handed [Ag(PAHT)]n helical chains. For compound 2, the 3D network is comprised of 2D sheet by strongly Ag–O and weakly Ag(I)…Ag(I) interactions. In compound 3, it is infrequently observed that dodecanuclear copper(I) units as secondary building units (SBUs) construct 3D network by the ligands CA3− with a rare uninodal 10-connected bct topology (312.428.55). The photoluminescent properties of three compounds have also been measured.