Magneto-structural studies on a number of doubly end-on cyanate and azide bridged dinuclear nickel(ii) complexes with {NO} donor Schiff base ligands.

Two new doubly -N bridged (1 and 3) and six new doubly -NCO bridged Ni complexes (2, 4-8) with six different NO donor Schiff base ligands have been synthesized and magneto-structurally characterized. All these neutral complex molecules are isostructural and constitute edge sharing bioctahedral structures. Magnetic studies revealed that all these complexes exhibit ferromagnetic interaction through bridging pseudohalides with ferromagnetic coupling constant being significantly higher for azide-bridged complexes than that of the cyanate analogues.

A Carbonate-Templated Decanuclear Mn Nanocage with Two Different Silsesquioxane Ligands.

The mild reaction of the preorganized silsesquioxane precursor with Mn(II) acetate under ambient conditions results in a mixed-valent {MnMn} nanocage () which is protected by both acyclic trimer [Si3] and cyclic tetramer [Si4]. Serendipitous capture of atmospheric CO as a μ-carbonate anion placed at the center supports the formation of the cluster. The magnetic analysis reveals the strong antiferromagnetic interactions between Mn ions.

Carboxylic acid-tuned nickel(ii) clusters: syntheses, structures, solution behaviours and magnetic properties.

Three novel cicada-like nickel(ii) clusters, formulated as [Ni(bdped)(mba)(Hdmpz)(NO)(HO)]·4MeCN (SD/Ni6b), [Ni(bdped)(tca)(Hdmpz)(MeOH)(HO)]·MeOH (SD/Ni5a) and [Ni(Hbdped)(ba)(Hdmpz)]·2NO·2MeCN (SD/Ni4a), were obtained by tuning the auxiliary carboxylic acids, where Hbdped = 1,2-bis-(3,5-dimethylpyrazol-1-yl)-ethane-1,2-diol; Hmba = 2-methylbenzoic acid; Hdmpz = 3,5-dimethyl-1H-pyrazole; Htca = 3-thiophenecarboxylic acid; and Hba = benzoic acid. The structures of SD/Ni6b, SD/Ni5a and SD/Ni4a are built from a central NiO opened cube, appending two to zero NiNO octahedra. The solution behaviours of SD/Ni6b, SD/Ni5a and SD/Ni4a were studied in detail via an ESI-MS technique and their solution stabilities were confirmed.

Prediction of Task Performance From Physiological Features of Stress Resilience.

In this paper, we investigate the potential of generic physiological features of stress resilience in predicting air traffic control (ATC) candidates' performance in a highly-stressful low-fidelity ATC simulator scenario. Stress resilience is highlighted as an important occupational factor that influences the performance and well-being of air traffic control officers (ATCO). Poor stress management, besides the lack of skills, can be a direct cause of poor performance under stress, both in the selection process of ATCOs and later in the workplace.

Copper(II)-Assisted Ligand Fragmentation Leading to Three Families of Metallamacrocycle.

We present an unprecedented copper(II)-assisted organic ligand fragmentation process under basic conditions leading to several ligands within three families of metallamacrocycle, Cu, Cu, and Cu. The sequential multistep reaction include (i) the deprotonation of the starting alcohol, 1,2-bis(3,5-dimethyl-pyrazol-1-yl)ethane-1,2-diol () to its diolate followed by complexation through six bonds (μ) to three copper atoms in a ring, (ii) the breaking of the ethane-pyrazole C-N bonds by the different solvent alcohols to form 1-(3,5-dimethyl-pyrazol-1-yl)-2-methoxyethane-1,2-diolate () or 2-(3,5-dimethyl-pyrazol-1-yl)-2-hydroxyacetate (), while retaining coordination to the copper centers and (iii) the final step to ethane-1,1,2,2-tetraolate, CHO (). Importantly, the latter product, only observed on two previous occasions, occupies the core of Cu and Cu through exceptionally eight coordination bonds (μ).

Self-assembly of a nonanuclear Ni cluster via atmospheric CO fixation: synthesis, structure, collision-induced dissociation mass spectrometry and magnetic property.

A novel nonanuclear nickel(ii) cluster identified as [Ni9(OH)6(CO3)2(ba)8(Hdmpz)6(DMF)2]·EtOH·2DMF (SD/Ni9a, Hba = benzoic acid, Hdmpz = 3,5-dimethyl-1H-pyrazole) is successfully constructed from mixed ligands. The single-crystal X-ray diffraction (SCXRD) structural analysis confirms the composition and reveals the "drum-like" inner core structure surrounded by ba- and DMF. Six Hdmpz ligands in their neutral form further sandwich the "drum" up and down, and is hydrogen bonded with two carbonate anions that are derived from the atmospheric CO2 with the help of Et3N.

Magnetoelectric Coupling Springing Up in Molecular Ferroelectric: [N(CH)CH][FeCl].

A molecule-based ferroelectric triethylmethylammonium tetrachloroferrate(III) ([N(CH)CH][FeCl]) powder was designed as a multifunctional material exhibiting excellent multiple bistability. Prepared by the slow evaporation method at room temperature, the compound crystallizes in the non-centrosymmetric assembly of hexagonal symmetry (6 space group) which undergoes a reversible temperature-triggered phase transition pinpointed at 363 K to the centrosymmetric packing within the 6/ space group. Aside from the inseparable role of the symmetry-breaking process smoothly unveiled from the X-ray powder diffraction data, a striking change in the dielectric permittivity observed during the paraelectric-to-ferroelectric phase transition directly discloses the bistable dielectric behavior-an exceptionally high increase in the dielectric permittivity of about 360% at 100 kHz across the heating and cooling cycles is direct proof showing the highly desirable stimuli-responsive electric ordering in this improper ferroelectric architecture.

An Octanuclear Cobalt Cluster Protected by Macrocyclic Ligand: In Situ Ligand-Transformation-Assisted Assembly and Single-Molecule Magnet Behavior.

Macrocyclic molecules with multiple coordination sites have been widely used as promising ligands to build polynuclear metal clusters; however, cyclic silsesquioxane-based metal clusters are still rare. Herein, we report a new octanuclear Co-silsesquioxane cluster [Co(OH){(MeSiO)}(bpy)(Obpy)] (; SD = SunDi), wherein the Co disc-like core is sandwiched by two hexamethylcyclohexasiloxanolate ligands (MeSiO) at two poles and finally encircled by two bpy (bpy = 2,2'-bipyridine) and two Obpy (HObpy = 6-hydroxy-2,2'-bipyridine) ligands at the equatorial region. Interestingly, both MeSi(OMe) and bpy undergo in situ transformations to generate hexameric cyclic (MeSiO) and Obpy, respectively.

A Polyoxochromate Templated 56-Nuclei Silver Nanocluster.

Most of polyoxometallates (POMs) templated silver nanoclusters recorded so far are polyoxomolybdates and polyoxotungstates; however, as congeneric polyoxochromates, they are rarely observed in silver nanoclusters. Herein, a high-nuclearity polyoxochromate, (CrCrO), is uncovered in a novel silver nanocluster () as an anion template. The mixed-valent (CrCrO) consists of four edge-sharing CrO octahedra and eight CrO tetrahedra, which are fused together by sharing one or two vertexes.

Self-Organization into Preferred Sites by Mg, Mn, and Mn in Brucite-Structured M Cluster.

The search for functional materials, for example those aiming at microelectronics, magnetic recording, and catalysis, often ventures into mixed metal systems to achieve optimization of the properties. Thus, understanding site preference and self-organization is crucial but hard to implement. Herein, we present a system whereby Mg, Mn, and Mn ions selectively locate exact positions within the Brucite-structured cluster, MnMg, [Mn⊂Mg⊂MnMn( L)(OH)(N)](ClO)·12CHCN, H L = 1-(hydroxymethyl)-3,5-dimethylpyrazolate).

Nanocomposites comprised of homogeneously dispersed magnetic iron-oxide nanoparticles and poly(methyl methacrylate).

Nanocomposites with a high, uniform loading of magnetic nanoparticles are very desirable for applications such as electromagnetic shielding and cancer treatment based on magnetically induced hyperthermia. In this study, a simple and scalable route for preparing nanocomposites with a high, uniform loading of magnetic nanoparticles is presented. The magnetic iron-oxide nanoparticles were functionalized with a methacrylate-based monomer that copolymerized in a toluene solution with the methyl methacrylate (MMA) monomer.

Two Unprecedented POM-Based Inorganic-Organic Hybrids with Concomitant Heteropolytungstate and Molybdate.

Two novel POM-based inorganic-organic hybrids, [Cu(2,2'-bipy)(MoO)(SiWO)] (1), and {[Cu(ppz)(HO)(MoO)(SiWO)]·4HO} (2) (2,2'-bipy = 2,2'-bipyridine, Hppz = 3-(pyrid-2-yl)pyrazole), have been constructed from heteropolytungstates and molybdates. Two compounds have been identified by single crystal X-ray diffraction, elemental analysis, and FT-IR. Compound 1 shows a 1D (one-dimensional) chain structure constructed from classical Keggin heteropolytungstate [SiWO] clusters and [Cu(2,2'-bipy)] modified isopolymolybdates [MoO].

pH-Controlled assembly of two novel Dawson-sandwiched clusters involving the in situ reorganization of trivacant α-[P2W15O56](12-) into divacant α-[P2W16O57](8.).

Modified classical trivacant Wells-Dawson α-[P2W15O56](12-) and the assembly of related sandwiched transition metal clusters are of interest, but surprisingly few reports of these materials exist because of the sensitivity of α-[P2W15O56](12-) to the assembly environment. Herein, we describe the pH-controlled assembly of two novel Dawson-sandwiched clusters, (H2bpz)6[Co2(P2W16O57)2]·22H2O (1, bpz = 3,3',5,5'-tetramethyl-4,4'-bipyrazole) and (H2bpz)6[Co3H2(P2W16O57)(P2W15O56)(H2O)]·12H2O (2), involving the in situ transformation of α-[P2W15O56](12-). Both clusters were characterized by X-ray single-crystal diffraction, FT-IR spectroscopy, UV-Visible spectroscopy, thermogravimetric analysis, powder X-ray diffraction, and elemental analyses.

Bacterial chemotaxis and entropy production.

Entropy production is calculated for bacterial chemotaxis in the case of a migrating band of bacteria in a capillary tube. It is found that the speed of the migrating band is a decreasing function of the starting concentration of the metabolizable attractant. The experimentally found dependence of speed on the starting concentration of galactose, glucose and oxygen is fitted with power-law functions.

Mathematical modeling of the myosin light chain kinase activation.

The mathematical model presented here describes the interactions among Ca2+, calmodulin (CaM), and myosin light chain kinase (MLCK) and consists of a kinetic scheme taking into account 7 reactions instead of 12 as proposed previously. We derive a system of 5 nonlinear ordinary differential equations. Solving it yields the prediction of active MLCK as a function of [Ca2+] whereby the active MLCK is defined to be proportional to the Ca4CaM.