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.

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.

Non-centrosymmetric Rb2Mn2(MoO4)3.

The title compound, dirubidium dimanganese(II) tris-(tetra-oxo-molyb-date), Rb2Mn2(MoO4)3, was prepared by solid-state reactions. The structure can be described as being composed of MnO6 octa-hedra sharing corners with MoO4 tetra-hedra. The three-dimensional framework contains cavities in which the rubidium ions are located. The Rb(+) cations are within distorted nine- and 12-vertex polyhedra. The pairs of different Mn(2+) and Rb(+) cations are each located on threefold rotation axes.. Rb2Mn2(MoO4)3 is isotypic with compounds of the Cs2 M 2Mo3O12 (M = Ni, Fe) family. A comparative structural description is provided between the structure of the title compound and those of related phases. Differences with structures such as alluaudite are discussed.

ß-K3Fe(MoO4)2Mo2O7.

The title compound, tripotassium iron(III) bis-(ortho-molyb-date) dimolybdate, was obtained by a solid-state reaction. The main structural building units are one FeO6 octa-hedron, two MoO4 tetra-hedra and one Mo2O7 dimolybdate group, all with point group symmetries m. These units are linked via corner-sharing to form ribbons parallel to [010]. The three K(+) cations are located between the ribbons on mirror planes and have coordination numbers of 10 and 12. Two O atoms of one of the MoO4 tetra-hedra of the dimolybdate group are disordered over two positions in a 0.524 (11):0.476 (11) ratio. The structure of the title compound is compared briefly with that of Rb3FeMo4O15.

α-NH4Fe(HAsO4)2.

The title compound α-ammonium iron(III) bis-[hydro-gen arsenate(V)], α-NH4Fe(HAsO4)2 (or poly[ammonium bis-(µ-hydro-gen arsenato)ferrate(III)], {NH4[Fe(HAsO4)2]} n ), syn-the-sized hydro-thermally, is isostructural with NH4Fe(HPO4)2. Condensation of the hydro-gen arsenate groups with FeO6 coordination octa-hedra via common corners results in an overall three-dimensional framework containing inter-connected channels parallel to the a-, b- and c-axis directions. The NH4 (+) cations are located in three inter-secting tunnels, which is promising as an ion exchange. Hydrogen bonding of the types O-H⋯O and N-H⋯O consolidates the packing of the structure. The distortion of the coordination polyhedra is analyzed by means of the effective coordination number and distortion indices. Structural relationships with other compounds of general formula M (I) M (III)[HXO4)]2 (X = P, As) are discussed.

4-Aza-niumyl-2,2,6,6-tetra-methyl-piperidin-1-ium dinitrate.

In the crystal structure of the title salt, C9H22N2 (2+)·2NO3 (-), the piperidine ring of the dication adopts a chair conformation and the orientation of the C-NH3 bond is equatorial. The ions are linked by normal and bifurcated N-H⋯O hydrogen bonds in R 2 (2)(6), two R 4 (2)(8) and R 3 (4)(14) graf-set motifs, generating a three-dimensional network.

Na1.67Mn2.17(MoO4)3.

The title compound, disodium dimanganese(II) tris-[ortho-molybdate(VI)], was prepared by solid-state reactions. The structure can be described as being composed of Mn2Mo2O14 double-chains that are inter-connected by corner-sharing with MoO4 tetra-hedra, leading to a three-dimensional framework with channels propagating in [100] and [001] in which the Na(+) counter-cations are located. One of these Na sites is located on an inversion centre, one is partially occupied [occupancy 0.341 (9)], and one is statistically occupied by Na and Mn in a ratio of 0.829 (5):0.171 (5). Na1.67Mn2.17(MoO4)3 is isotypic with structures of the Ag2 M 2(MoO4)3 (M = Zn, Mg, Co, Mn) family. A comparative structural description is provided between the structure of the title compound and those of related phases containing (MXO8) n chains (M = Mo, Mn and X = As) or M 2O10 (M = Mo, Mn, Nb, V) dimers.

ß-Li0.37Na0.63Fe(MoO4)2.

The title compound, lithium/sodium iron(III) bis-[ortho-molyb-date(VI)], was obtained by a solid-state reaction. The main structure units are an FeO6 octa-hedron, a distorted MoO6 octa-hedron and an MoO4 tetra-hedron sharing corners. The crystal structure is composed of infinite double MoFeO11 chains along the b-axis direction linked by corner-sharing to MoO4 tetra-hedra so as to form Fe2Mo3O19 ribbons. The cohesion between ribbons via mixed Mo-O-Fe bridges leads to layers arranged parallel to the bc plane. Adjacent layers are linked by corners shared between MoO4 tetra-hedra of one layer and FeO6 octa-hedra of the other layer. The Na(+) and Li(+) ions partially occupy the same general position, with a site-occupancy ratio of 0.631 (9):0.369 (1). A comparison is made with AFe(MoO4)2 (A = Li, Na, K and Cs) structures.

Crystal structure of alluaudite-type Na4Co(MoO4)3.

The title compound, tetra-sodium cobalt(II) tris-[molyb-date(IV)], was prepared by solid-state reactions. The structure is isotypic with Na3In2(AsO4)3 and Na3In2(PO4)3. The main structural feature is the presence of infinite chains of edge-sharing X 2O10 (X = Co/Na) dimers, which are linked by MoO4 tetra-hedra, forming a three-dimensional framework enclosing two types of hexa-gonal tunnels in which Na(+) cations reside. In this alluaudite structure, Co and Na atoms are located at the same general site with occupancies of 0.503 (5) and 0.497 (6), respectively. The other three Na and one of the two Mo atoms lie on special positions (site symmetries 2, -1, 2 and 2, respectively). The structure is compared with similar structures and other members of alluaudite family.

ß-Nb9VO25.

The title compound, nona-niobium vanadium penta-cosa-oxide, was prepared by a solid-state reaction at 1198 K. It is isotypic with Nb9AsO25, Nb9PO25 and Ta9VO25. The structure consists of NbO6 octa-hedra (one with 4/m.. and two with m.. symmetry) and VO4 tetra-hedra (-4.. symmetry) sharing corners and edges to form a three-dimensional framework. This framework can be considered as a junction between ribbons made up from NbO6 octa-hedra and chains of NbO6 octa-hedra and chains of VO4 tetra-hedra. The V site shows half-occupancy, hence one half of the VO4 tetra-hedra is unoccupied. The structural differences with α-Nb9VO25, VOSO4, SbOPO4 and NbOPO4 oxides are discussed.

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.

Na(3)Al(AsO(4))(2).

The structure of the title compound tris-odium aluminium bis-(arsenate), Na(3)Al(AsO(4))(2), is built up from AlO(4) and AsO(4) corner-sharing tetra-hedra, forming an undulating two-dimensional framework parallel to (100). The layers are constituted of large Al(6)As(6)O(36) rings made up from six AlO(4) and AsO(4) tetra-hedra in which two sodium cations are situated, the third sodium cation being located in the inter-layer space. The structural relationships between the title compound and Na(3)Fe(PO(4))(2), NaAlCo(PO(4))(2) and Al(5)Co(3)(PO(4))(8) are discussed.

K0.78Na0.22MoO2AsO4.

The title compound, potassium sodium dioxidomolybden-um(VI) arsenate, K0.78Na0.22MoO2AsO4, was synthesized by a solid-state reaction route. The structure is built up from corner-sharing MoO6 octa-hedra and AsO4 tetra-hedra, creating infinite [MoAsO8]∞ chains running along the b-axis direction. As, Mo and all but one O atom are on special positions (4c) with m symmetry and K (occupancy 0.78) is on a position (4a) of -1 in the tunnels. The possible motion of the alkali cations has been investigated by means of the bond-valance sum (BVS) model. The simulation shows that the Na(+) motion appears to be easier mainly along the b-axis direction. Structural relationships between the different compounds of the AMoO2AsO4 (A = Ag, Li, Na, K, Rb) series and MXO8 (M = V; X = P, As) chains are discussed.

K(MoO2)4O3(AsO4).

A new compound with a non-centrosymmetric structure, potassium tetra-kis-[dioxomolybdenum(IV)] arsenate trioxide, K(MoO2)4O3(AsO4), has been synthesized by a solid-state reaction. The [(MoO2)4O3(AsO4)](+) three-dimensional framework consists of single arsenate AsO4 tetra-hedra, MoO6 octa-hedra, MoO5 bipyramids and bi-octa-hedral units of edge-sharing Mo2O10 octa-hedra. The [Mo2O8]∞ octa-hedral chains running along the a-axis direction are connected through their corners to the AsO4 tetra-hedra, MoO6 octa-hedra and MoO5 bipyramids, so as to form large tunnels propagating along the a axis in which the K(+) cations are located. This structure is compared with compounds containing M 2O10 (M = Mo, V, Fe) dimers and with those containing M 2O8 (M = V) chains.

Na7Cr4(P2O7)4PO4.

The title compound, hepta-sodium tetra-chromium(III) tetra-kis-(diphosphate) orthophosphate, was synthesized by solid-state reaction. Its structure is isotypic with that of Na7 M 4(P2O7)4PO4 (M = In, Al) compounds and is made up from a three-dimensional [(CrP2O7)4PO4](7-) framework with channels running along [001]. The three Na(+) cations are located in the voids of the framework. One of the cations is situated on a general position, one is equally disordered around a twofold rotation axis and one is on a fourfold rotoinversion axis. The isolated PO4 tetra-hedron of the anionic framework is also situated on the -4 axis. Structural relationships between the title compound and different diphosphates containing MP2O11 units (M = Mo, V) are discussed.

Li0.5Al0.5Mg2(MoO4)3.

The title compound, lithium/aluminium dimagnesium tetra-kis-[orthomolybdate(VI)], was prepared by a solid-state reaction route. The crystal structure is built up from MgO6 octa-hedra and MoO4 tetra-hedra sharing corners and edges, forming two types of chains running along [100]. These chains are linked into layers parallel to (010) and finally linked by MoO4 tetra-hedra into a three-dimensional framework structure with channels parallel to [001] in which lithium and aluminium cations equally occupy the same position within a distorted trigonal-bipyramidal coordination environment. The title structure is isotypic with LiMgIn(MoO4)3, with the In site becoming an Mg site and the fully occupied Li site a statistically occupied Li/Al site in the title structure.

Imidazolium trans-di-aqua-dioxalato-chromate(III) dihydrate.

In the title hydrated mol-ecular salt, (C3H5N2)[Cr(C2O4)2(H2O)2]·2H2O, the complete cation is generated by a crystallographic twofold rotation axis, with one C atom lying on the rotation axis. The complete anion is generated by crystallographic inversion symmetry (Cr(III) site symmetry -1), to generate a slightly distorted CrO6 octa-hedron with trans water mol-ecules and chelating oxalate dianions. The oxalate ion is almost planar (r.m.s. deviation = 0.017 Å) and the five-membered chelate ring is a shallow envelope with the metal ion displaced by 0.126 (1) Šfrom the ligand atoms. The crystal structure features O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds, which link the components into a three-dimensional network.

ß-K(VO2)2(PO4).

A new vanadium oxide, potassium bis-(dioxovanad-yl) phosphate, ß-K(VO2)2(PO4), has been synthesized by a solid-state reaction. In the title compound, the [V2PO8] framework is built up from infinite pyramidal [V2O8]∞ and [VPO7]∞ chains linked together by V-O-P bridges, leading to a three-dimensional framework which delimits two types of inter-secting tunnels running along [100] and [010] in which the four unique K(+) ions, showing coordination numbers of nine and ten, are located.

ß-Xenophyllite-type Na4Li0.62Co5.67Al0.71(AsO4)6.

The title compound, tetrasodium lithium cobalt aluminium hexa-(orthoarsenate), was synthesized by a solid state reaction route. In the crystal structure, Co(2+) ions are partially substituted by Al(3+) in an octa-hedral environment [M1 with site symmetry 2/m; occupancy ratio Co:Al = 0.286 (10):0.714 (10)]. The charge compensation is ensured by Li(+) cations sharing a tetra-hedral site with Co(2+) ions [M2 with site symmetry 2; occupancy ratio Co:Li = 0.690 (5):0.310 (5)]. The anionic unit is formed by two octa-hedra and three tetra-hedra linked only by corners. The CoM1M2As2O19 units associate to an open three-dimensional framework containing tunnels propagating along the a-axis direction. One Na(+) cation is located in the periphery of the tunnels while the other two are situated in the centres: all Na(+) cations exhibit half-occupancy. The structure of the studied material is compared with those of various related minerals reported in the literature.

Na3Co2(As0.52P0.48)O4(As0.95P0.05)2O7.

The title compound, trisodium dicobalt(II) (arsenate/phosphate) (diarsenate/diphosphate), was prepared by a solid-state reaction. It is isostructural with Na3Co2AsO4As2O7. The framework shows the presence of CoX22O12 (X2 is statistically disordered with As0.95P0.05) units formed by sharing corners between Co1O6 octa-hedra and X22O7 groups. These units form layers perpendicular to [010]. Co2O6 octa-hedra and X1O4 (X1 = As0.54P0.46) tetra-hedra form Co2X1O8 chains parallel to [001]. Cohesion between layers and chains is ensured by the X22O7 groups, giving rise to a three-dimensional framework with broad tunnels, running along the a- and c-axis directions, in which the Na(+) ions reside. The two Co(2+) cations, the X1 site and three of the seven O atoms lie on special positions, with site symmetries 2 and m for the Co, m for the X1, and 2 and m (× 2) for the O sites. One of two Na atoms is disordered over three special positions [occupancy ratios 0.877 (10):0.110 (13):0.066 (9)] and the other is in a general position with full occupancy. A comparison between structures such as K2CdP2O7, α-NaTiP2O7 and K2MoO2P2O7 is made. The proposed structural model is supported by charge-distribution (CHARDI) analysis and bond-valence-sum (BVS) calculations. The distortion of the coordination polyhedra is analyzed by means of the effective coordination number.