One-pot synthesis, structural investigation, antitumor activity and molecular docking approach of two decavanadate compounds.

Two bases-decavanadates coordination compounds [(C6H13N4)2][Mg(H2O)6]2[O28V10].6H2O (1) and [(C7H11N2)4][Mg(H2O)6][O28V10].4H2O (2) have been synthesized and well characterized using vibrational spectroscopy (infrared), UV-Visible analysis and single crystal X-ray diffraction technique. The formula unit, for both compounds, is composed by the decavanadate [V10O28]6-, hydrated magnesium ion, a counter anion and free water molecules. The transition metal adopts octahedral geometries in both compound (1) and (2). The existence of a multitude of hydrogen bonding interactions for both compounds provides a stable three-dimensional supramolecular structure. Optical absorption reveals a band gap energy indicating the semi-conductive nature of the compound. In this study, the cytotoxic and the anti-proliferative activities of compounds (1) and (2) on human cancer cells (U87 and MDA-MB-231) were investigated. Both compounds demonstrated dose-dependent anti-proliferative activity on U87 and MDA-MB-231 with respective IC50 values of 0.82 and 0.31 µM and 1.4 and 1.75 µM. These data provide evidence on the potential anticancer activity of [(C6H13N4)2][Mg(H2O)6]2[O28V10].6H2O and [(C7H11N2)4][Mg(H2O)2][O28V10].4H2O. Molecular docking of the compounds was also examined. Molecular docking studies were performed for both compounds against four target receptors and revealed better binding affinity with these targets in comparison to Cisplatin. Moreover, molecular docking investigations suggest that these compounds may function as potential inhibitors of proteins in brain and breast cells, exhibiting greater efficiency compared to Cisplatin.

Zinc Tetrafluoroborate-Mediated Ring Expansion of trans-Aziridine-2-carboxylates to cis-2-Iminothiazolidines and cis-Thiazolidine-2-iminium Tetrafluoroborates and Evaluation of Antimicrobial Activity.

Cis-2-iminothiazolidines and cis-thiazolidine-2-iminium tetrafluoroborates were successfully produced from trans-N-alkyl aziridine-2-carboxylates and phenyl/alkyl isothiocyanates mediated by zinc tetrafluoroborate in refluxing DCE. Reactions were performed via a complete regio- and stereoselective process to give the title iminothiazolidines and cis-thiazolidine-2-iminium salts in moderate to good yields (35 to 82%) with a wide substrate scope. In addition, the antibacterial activity evaluation of these compounds, as well as the minimum inhibitory concentration (MIC) determination, revealed that only four cis-thiazolidine-2-iminium salts showed growth inhibition against Bacillus cereus.

Structure, Optical and Magnetic Properties of Two Isomeric 2-Bromomethylpyridine Cu(II) Complexes [Cu(C6H9NBr)2(NO3)2] with Very Different Binding Motives.

Two isomeric 2-bromomethylpyridine Cu(II) complexes [Cu(C6H9NBr)2(NO3)2] with 2-bromo-5-methylpyridine (L1) and 2-bromo-4-methylpyridine (L2) were synthesized as air-stable blue materials in good yields. The crystal structures were different with [Cu(L1)2(NO3)2] (CuL1) crystallizing in the monoclinic space group P21/c, while the 4-methyl derivative CuL2 was solved and refined in triclinic P1¯. The orientation of the Br substituents in the molecular structure (anti (CuL1) vs. syn (CuL2) conformations) and the geometry around Cu(II) in an overall 4 + 2 distorted coordination was very different with two secondary (axially elongated) Cu-O bonds on each side of the CuN2O2 basal plane in CuL1 or both on one side in CuL2. The two Br substituents in CuL2 come quite close to the Cu(II) centers and to each other (Br⋯Br ~3.7 Å). Regardless of these differences, the thermal behavior (TG/DTA) of both materials is very similar with decomposition starting at around 160 °C and CuO as the final product. In contrast to this, FT-IR and Raman frequencies are markedly different for the two isomers and the UV-vis absorption spectra in solution show marked differences in the π-π* absorptions at 263 (CuL2) or 270 (CuL1) nm and in the ligand-to-metal charge transfer bands at around 320 nm which are pronounced for CuL1 with the higher symmetry at the Cu(II) center, but very weak for CuL2. The T-dependent susceptibility measurements also show very similar results (µeff = 1.98 µB for CuL1 and 2.00 µB for CuL2 and very small Curie-Weiss constants of about -1. The EPR spectra of both complexes show axial symmetry, very similar averaged g values of 2.123 and 2.125, respectively, and no hyper-fine splitting.

First Report of the Biosynthesis and Characterization of Silver Nanoparticles Using Scabiosa atropurpurea subsp. maritima Fruit Extracts and Their Antioxidant, Antimicrobial and Cytotoxic Properties.

Candida and dermatophyte infections are difficult to treat due to increasing antifungal drugs resistance such as fluconazole, as well as the emergence of multi-resistance in clinical bacteria. Here, we first synthesized silver nanoparticles using aqueous fruit extracts from Scabiosa atropurpurea subsp. maritima (L.). The characterization of the AgNPs by means of UV, XRD, FTIR, and TEM showed that the AgNPs had a uniform spherical shape with average sizes of 40-50 nm. The biosynthesized AgNPs showed high antioxidant activity when investigated using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. The AgNPs displayed strong antibacterial potential expressed by the maximum zone inhibition and the lowest MIC and MBC values. The AgNPs revealed a significant antifungal effect against the growth and biofilm of Candida species. In fact, the AgNPs were efficient against Trichophyton rubrum, Trichophyton interdigitale, and Microsporum canis. The antifungal mechanisms of action of the AgNPs seem to be due to the disruption of membrane integrity and a reduction in virulence factors (biofilm and hyphae formation and a reduction in germination). Finally, the silver nanoparticles also showed important cytotoxic activity against the human multiple myeloma U266 cell line and the human breast cancer cell line MDA-MB-231. Therefore, we describe new silver nanoparticles with promising biomedical application in the development of novel antimicrobial and anticancer agents.

Green synthesis of silver nanoparticles using mixed leaves aqueous extract of wild olive and pistachio: characterization, antioxidant, antimicrobial and effect on virulence factors of Candida.

In this study, a successfully rapid, simple approach was applied for biosynthesis of silver nanoparticles AgNPs using for the first time the mixed leaves extract of Olea europaea subsp. europaea var. sylvestris and Pistacia lentiscus from natural association aimed to enhance their antimicrobial potential. The plant extract acts both as reducing and capping agents. When the aqueous extract was added to AgNO3 solution, the color was changed from pale to yellow to brown indicating the reduction of Ag ions and synthesis of silver nanoparticles (AgNPs) without any solvent or hazardous reagents. The green synthesized AgNPs were characterized by UV-Vis spectrophotometer, FTIR spectrum and the X-ray crystallography. The AgNPs showed superior antioxidant activity measured by DPPH, Ferric Antioxidant Reducing Power (FRAP) as well as the total antioxidant activity methods. Moreover, the analysis of phytochemical constituents including flavonoids, tannins, alkaloids and total polyphenols contents mentioned the most richness of the silver nanoparticles compared to plant extract. The new synthesized AgNPs demonstrated the bactericidal and fungicidal effects against all the tested bacterial and fungal strains and found to limit the spore germination of filamentous fungi. AgNPs also gave an anti-biofilm activity and synergistic effect with the conventional antibiotic's drugs. Here we firstly describe the silver nanoparticles effect on virulence factors of Candida species by reduction of enzymes like proteinase and phospholipase, inhibition of morphogenesis of Candida albicans cells. This natural product, acquiring these properties, should be promoted to be used in pharmaceutical and medical industries in future.

Biosynthesis and Characterization of Silver Nanoparticles from the Extremophile Plant Aeonium haworthii and Their Antioxidant, Antimicrobial and Anti-Diabetic Capacities.

The present paper described the first green synthesis of silver nanoparticles (AgNPs) from the extremophile plant Aeonium haworthii. The characterization of the biosynthesized silver nanoparticles was carried out by using UV-Vis, FTIR and STM analysis. The antioxidant, antidiabetic and antimicrobial properties were also reported. The newly described AgNPs were spherical in shape and had a size of 35-55 nm. The lowest IC50 values measured by the DPPH assay indicate the superior antioxidant behavior of our AgNPs as opposed to ascorbic acid. The silver nanoparticles show high antidiabetic activity determined by the inhibitory effect of α amylase as compared to the standard Acarbose. Moreover, the AgNPs inhibit bacterial growth owing to a bactericidal effect with the MIC values varying from 0.017 to 1.7 µg/mL. The antifungal action was evaluated against Candida albicans, Candida tropicalis, Candida glabrata, Candida sake and non-dermatophytic onychomycosis fungi. A strong inhibitory effect on Candida factors' virulence was observed as proteinase and phospholipase limitations. In addition, the microscopic observations show that the silver nanoparticles cause the eradication of blastospores and block filamentous morphogenesis. The combination of the antioxidant, antimicrobial and antidiabetic behaviors of the new biosynthesized silver nanoparticles highlights their promising use as natural phytomedicine agents.

Crystal structure, Hirshfeld surface analysis and physicochemical characterization of bis-[4-(di-methyl-amino)-pyridinium] di-µ-chlorido-bis[di-chlorido-mercurate(II)].

The title mol-ecular salt, (C7H11N2)2[Hg2Cl6], crystallizes with two 4-(di-methyl-amino)-pyridinium cations (A and B) and two half hexa-chlorido-dimercurate(II) anions in the asymmetric unit. The organic cations exhibit essentially the same features with an almost planar pyridyl ring (r.m.s. deviations of 0.0028 and 0.0109 Å), which forms an inclined dihedral angle with the dimethyamino group [3.06 (1) and 1.61 (1)°, respectively]. The di-methyl-amino groups in the two cations are planar, and the C-N bond lengths are shorter than that in 4-(di-methyl-amino)-pyridine. In the crystal, mixed cation-anion layers lying parallel to the (010) plane are formed through N-H⋯Cl hydrogen bonds and adjacent layers are linked by C-H⋯Cl hydrogen bonds, forming a three-dimensional network. The analyses of the calculated Hirshfeld surfaces confirm the relevance of the above inter-molecular inter-actions, but also serve to further differentiate the weaker inter-molecular inter-actions formed by the organic cations and inorganic anions, such as π-π and Cl⋯Cl inter-actions. The powder XRD data confirms the phase purity of the crystalline sample. Furthermore, the vibrational absorption bands were identified by IR spectroscopy and the optical properties were studied by using optical UV-visible absorption spectroscopy.

Mercerization effect on structure and electrical properties of cellulose: Development of a novel fast Na-ionic conductor.

Mercerized cellulose (alkali cellulose C6H10O5* NaOH) was obtained by treatment of cotton linters (cellulose) with aqueous sodium hydroxide. Cellulose and alkali-cellulose samples with relative density of 78% and 79% were obtained after sintering the material in air at optimal sintering temperatures of 423 K and 473 K, respectively. The electrical properties of the samples were studied by impedance spectroscopy in the frequency range from 13 MHz to 50 Hz at temperatures between 393 K and 493 K. The influence of cellulose mercerization on electrical properties of cotton linters was observed. The cellulose behaves like an electrical insulator. Contrariwise, the alkali-cellulose is a fast-ionic conductor with a conductivity value of σ473 K = 3.22 × 10-6 S cm-1 having activation energies of 0.49 eV and 0.68 eV at temperature range of 393 K-458 K and 459 K-500 K, respectively. The change of activation energy value has been discussed in relation to thermal stability.

Synthesis and structural study of tris-(2,6-di-amino-pyridinium) bis-(oxalato)dioxidovanadate(V) 2.5-hydrate.

Crystals of the title compound, (C5H8N3)3[VO2(C2O4)2]·2.5H2O, a mononuclear VV complex, were obtained by slow evaporation at room temperature of an aqueous solution containing vanadium pentoxide, oxalic acid and 2,6-di-amino-pyridine. The asymmetric unit contains one bis-(oxalato)dioxovanadate(V) anionic complex, three 2,6-di-amino-pyridinium cations and two and a half uncoordinated water mol-ecules. The mononuclear vanadium(V) anions are connected to the organic cations and water mol-ecules through a strong N-H⋯O and O-H⋯O hydrogen-bond network, consolidated by π-π stacking inter-actions, to form a three-dimensional structure.

Crystal structure, Hirshfeld surface analysis and energy framework calculation of the first oxoanion salt containing 1,3-cyclo-hexa-nebis(methyl-ammonium): [3-(aza-niumylmeth-yl)cyclo-hex-yl]methanaminium dinitrate.

The title salt, C8H20N22+·2NO3-, was obtained by a reaction between 1,3-cyclohexa-nebis(methyl-amine) and nitric acid. The cyclo-hexane ring of the organic cation is in a chair conformation with the methyl-ammonium substituents in the equatorial positions and the two terminal ammonium groups in a trans conformation. In the crystal, mixed cation-anion layers lying parallel to the (010) plane are formed through N-H⋯O hydrogen-bonding inter-actions; these layers are formed by infinite undulating chains running parallel to the [001] direction. The overall inter-molecular inter-actions involved in the structure were qu-anti-fied and fully described by Hirshfeld surface analysis. In addition, energy-framework calculations were used to analyse and visualize the three-dimensional topology of the crystal packing. The electrostatic energy framework is dominant over the dispersion energy framework.

Structure cristalline, caractérisation spectroscopique, calcul DFT et analyse de surface Hirshfeld du perchlorate de p-toluidinium.

The synthesis of p-toluidinium perchlorate (systematic name: 4-methyl-anilinium perchlorate), C7H10N+·ClO4-, was carried out from an aqueous reaction of perchloric acid with p-toluidine. This compound was characterized by powder XRD, IR and UV-Vis spectroscopy. The structure was further confirmed by a single-crystal X-ray diffraction study. The crystal structure is formed by a succession of two-dimensional mol-ecular layers consisting of perchlorate anions and organic cations parallel to the (100) plane and located at x = 2n + ½ (n ∈ Z). Each mixed layer is formed by infinite chains {C7H10N+·ClO4-} n parallel to the [010] direction and developing along the c axis, generating R24(8), R22(4) and R44(12) graph-set motifs. The results of a theoretical study using the DFT method at the B3LYP/6-311++G(d,p) level are in good agreement with the experimental data. Hirshfeld surface and fingerprint plots reveal that the structure is dominated by O⋯H/H⋯O (54.2%), H⋯H (26.9%) and C-H ⋯π (14.3%) contacts. The studied crystal was refined as a two-component twin.

Elaboration, structural study and validation of a new NASICON-type structure, Na0.72(Cr0.48,Al1.52)(Mo2.77,Al0.23)O12.

The title compound, sodium chromium/aluminium molybdenum/aluminium dodeca-oxide, Na0.72Cr0.48Al1.74Mo2.77O12, was prepared by solid-state reaction. Its crystal structure is related to NaSICON-type compounds. The framework is built up from M1O6 (M1 = Cr/Al) octa-hedra and M2O4 (M2 = Mo/Al) tetra-hedra inter-connected by corners. The three-dimensional framework contains cavities in which sodium cations are located. Two validation models (BVS and CHARDI) were used to confirm the proposed structural model. The mobility of Na+ ions in the structure has been investigated by theoretical means.

Crystal structure and Hirshfeld surface analysis of bis-(2,6-di-amino-pyridinium) tetra-chlorido-cobaltate(II).

In the title mol-ecular salt, (C5H8N3)2[CoCl4], the cations are protonated at their pyridine N atoms and the anion is an almost regular tetra-hedron. The crystal structure consists of alternating inorganic layers, built from tetra-chlorido-cobaltate anions, and organic layers formed by protonated cations of 2,6-di-amino-pyridinium. The crystal packing is governed by C/N-H⋯Cl hydrogen-bonding inter-actions between the organic and the inorganic ions and Cl⋯Cl inter-actions. Moreover, the cations show a π-π stacking inter-action [inter-centroid distance = 3.763 (2) Å]. The prevalence of these inter-actions is illustrated by an analysis of the three-dimensional Hirshfeld surface and by two-dimensional fingerprint plots.

Structure cristalline et analyses thermique et de surface Hirshfeld du diperchlorate de 4-aza-niumyl-2,2,6,6-tétraméthylpipéridin-1-ium.

The synthesis of 4-aza-niumyl-2,2,6,6-tetra-methyl-piperidin-1-ium diperchlorate, C9H22N22+·2ClO4-, was carried out from an aqueous reaction of perchloric acid with 4-amino-2,2,6,6-tetra-methyl-piperidine. This compound was characterized by TGA-DSC analysis and single-crystal X-ray diffraction. The piperidine ring of the dication adopts a chair conformation and the orientation of the C-NH3 bond is equatorial. One of the two crystallographically independent perchlorate anions exhibits disorder [occupancies 0.625 (7) and 0.375 (7)]. The crystal packing is constituted by a succession of mixed layers parallel to the (-102) plane, made up of C9H22N22+ dications and ClO4- anions. These ions are linked by normal and bifurcated N-H⋯O hydrogen bonds with R44(12) graph-set motifs, generating a two-dimensional network. The inter-molecular inter-actions in the crystal structure were qu-anti-fied and analysed using Hirshfeld surface analysis.

An arsenate with the α-CrPO4 structure type, NaCa1-xNi3-2xAl2x(AsO4)3 (x = 0.23): crystal structure, charge-distribution and bond-valence-sum analyses.

Since the discovery of electrochemically active LiFePO4, materials with tunnel and layered structures built up of transition metals and polyanions have become the subject of much research. A new quaternary arsenate, sodium calcium trinickel aluminium triarsenate, NaCa1-xNi3-2xAl2x(AsO4)3 (x = 0.23), was synthesized using the flux method in air at 1023 K and its crystal structure was determined from single-crystal X-ray diffraction (XRD) data. This material was also characterized by qualitative energy-dispersive X-ray spectroscopy (EDS) analysis and IR spectroscopy. The crystal structure belongs to the α-CrPO4 type with the space group Imma. The structure is described as a three-dimensional framework built up of corner-edge-sharing NiO6, (Ni,Al)O6 and AsO4 polyhedra, with channels running along the [100] and [010] directions, in which the sodium and calcium cations are located. The proposed structural model has been validated by bond-valence-sum (BVS) and charge-distribution (CHARDI) tools. The sodium ionic conduction pathways in the anionic framework were investigated by means of the bond-valence site energy (BVSE) model, which predicted that the studied material will probably be a very poor Na+ ion conductor (bond-valence activation energy ∼7 eV).

K1+2x Ni1-x Fe2(AsO4)3 (x = 0,125): un nouvel arséniate à structure de type α-CrPO4.

A new arsenate K1+2x Ni1-x Fe2(AsO4)3 (x = 1/8) {potassium nickel diiron(III) tris-[arsenate(V)]} was synthesized using a flux method and its crystal structure was determined from single-crystal X-ray diffraction data. This material was also characterized by qualitative energy dispersive X-ray spectroscopy (EDS) analysis. The crystal structure belongs to the α-CrPO4-structure type, space group Imma. It consists of a three-dimensional-framework built up from FeO6 and Ni0.875□1.25O6-octa-hedra and AsO4-tetra-hedra that are sharing corners and/or edges, generating tunnels running along the [010] and [001] directions in which the potassium cations are located. The proposed structural model was validated by bond-valence-sum calculations, charge-distribution (CHARDI) and Madelung energy analyses.

Crystal structure of bis-[4-(di-methyl-amino)-pyridinium] aqua-bis-(oxalato)oxidovanadate(IV) dihydrate.

The title organic-inorganic hybrid salt, (C7H11N2)2[V(C2O4)2O(H2O)]·2H2O, shows a distorted octa-hedral coordination environment for the vanadium(IV) atom in the anion (point group symmetry 2), with four O atoms from two symmetry-related chelating oxalate dianions and two O atoms in trans configuration from a coordinating water mol-ecule and a terminal vanadyl O atom. In the crystal, (001) layers of cations and anions alternate along [001]. The anionic layers are built up by inter-molecular O-H⋯O hydrogen bonds involving the coordinating and solvent water mol-ecules. The cationic layers are linked to the anionic layers via N-H⋯O hydrogen bonds between the pyridinium group and the non-coordinating O atoms of the oxalate group. The 4-(di-methyl-amino)-pyridinium cations are also engaged in π-π stacking with their anti-parallel neighbours [centroid-to-centroid distance = 3.686 (2) Å]. Considering all supra-molecular features, a three-dimensional network structure is accomplished.

Synthesis, crystal structure and charge-distribution validation of ß-Na4Cu(MoO4)3 adopting the alluadite structure-type.

Single crystals of a new variety of tetra-sodium copper(II) tris-[molybdate(VI)], Na4Cu(MoO4)3, have been synthesized by solid-state reactions and characterized by single-crystal X-ray diffraction. This alluaudite structure-type is characterized by the presence of infinite layers of composition (Cu/Na)2Mo3O14 parallel to the (100) plane, which are linked by MoO4 tetra-hedra, forming a three-dimensional framework containing two types of hexa-gonal channels in which Na(+) cations reside. The Cu(2+) and Na(2+) cations are located at the same general site with occupancies of 0.5. All atoms are on general positions except for one Mo, two Na (site symmetry 2) and another Na (site symmetry -1) atom. One O atom is split into two separate positions with occupancies of 0.5. The title compound is isotypic with Na5Sc(MoO4)4 and Na3In2As3O12. The structure model is supported by bond-valence-sum (BVS) and charge-distribution CHARDI methods. ß-Na4Cu(MoO4)3 is compared and discussed with the K4Cu(MoO4)3 and α-Na4Cu(MoO4)3 structures.

Crystal structure and spectroscopic analysis of a new oxalate-bridged Mn(II) compound: catena-poly[guanidinium [[aqua-chlorido-manganese(II)]-µ2-oxalato-κ(4) O (1),O (2):O (1'),O (2')] monohydrate].

As part of our studies on the synthesis and the characterization of oxalate-bridged compounds M-ox-M (ox = oxalate dianion and M = transition metal ion), we report the crystal structure of a new oxalate-bridged Mn(II) phase, {(CH6N3)[Mn(C2O4)Cl(H2O)]·H2O} n . In the compound, a succession of Mn(II) ions (situated on inversion centers) adopting a distorted octa-hedral coordination and bridged by oxalate ligands forms parallel zigzag chains running along the c axis. These chains are inter-connected through O-H⋯O hydrogen-bonding inter-actions to form anionic layers parallel to (010). Individual layers are held together via strong hydrogen bonds involving the guanidinium cations (N-H⋯O and N-H⋯Cl) and the disordered non-coordinating water mol-ecule (O-H⋯O and O-H⋯Cl), as well as by guanidinium π-π stacking. The structural data were confirmed by IR and UV-Visible spectroscopic analysis.

Synthèse, étude et validation structurale d'un triple bis-molybdate en couches, Ag0.60Na0.40Fe(MoO4)2 lié à yavapaiite.

The title compound, Ag0.60Na0.40Fe(MoO4)2 {silver sodium iron(III) bis-[molyb-date(VI)]}, was synthesized by a solid-state reaction. The structure is built up from FeO6 octa-hedra and MoO4 tetra-hedra sharing corners to form a two-dimensional framework parallel to the (001) plane. The occupationally disordered (Ag/Na)(+) cations are located in the inter-layer space. These [Fe(MoO4)2 (-)] n layers are similar to those in the isotypic yavapaiite-related structure of NaFe(MoO4)2. All atoms are on general positions except for Fe (site symmetry -1) and Ag/Na (site symmetry 2). The Ag/Na occupancies of the latter site were refined to 0.597 (4):0.403 (5). The title structure is compared to similar structures.