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Determines the factors which control the complex formation of PCP ligand based platinum and palladium macrocycles by studying the coordination behavior prior to C-M bond formation of the chelating aromatic PCP substrate. Formation and identification of complexes; X-ray crystal structure determination.

Examines an approach of influencing the electron density on a metal center by the presence of heteroatom in the trans-position of the aromatic ring of a terdentate chelating bis(phosphine) ligand. Results of using appropriate scectroscopic technique; Details of the experiment used.

Reports on a reaction promoted by a rhodium complex in which a methylene group can be abstracted from a methyl group and inserted into a variety of bonds. Requirement of a metal coordination geometry in the metal complex; Mechanism for the methylene group transfer.

Reports on the selective activation of a simple carbon-carbon (C-C) bond by a mononuclear rhodium complex in a neutral homogenous medium, tetrahydrofuran solution. Cleavage of C-C bonds by transition-metal containing heterogenous catalysts; Rh insertion into a C-C bond; Overpressure of H2; Competitive C-H and C-C activation.

Solid oxide fuel cells are characterized by a high efficiency for converting chemical energy into electricity and fuel flexibility. This research work focuses on developing durable and efficient anodes for solid oxide fuel cells (SOFCs) based on exsolving nickel from the perovskite structure. A-site-deficient La- and Ni-doped strontium titanates (La0.2Sr0.7Ti0.95Ni0.05O3−δ, LSTN) were synthesized using four different techniques and mixed with Ce0.8Gd0.2O2−δ (GDC) to form the SOFC anode. The synthesis routes of interest for comparison included solid-state, sol-gel, hydrothermal, and co-precipitation methods. LSTN powders were characterized via XRD, SEM, TPR, BET and XPS. In situ XRD during reduction was measured and the reduced powders were analyzed using TEM. The impact of synthesis route on SOFC performance was investigated. All samples were highly durable when kept at 0.5 V for 48 h at 800 °C with H2 fuel. Interestingly, the best performance was observed for the cell with the LSTN anode prepared via co-precipitation, while the conventional solid-state synthesis method only achieved the second-best results. [ABSTRACT FROM AUTHOR]

The article discusses a study on the catalytic oxidation of hydrazo compounds boosted by a catalyst mixture comprising titanium trichloride (TiCl3) and hydrogen bromide (HBr). TiCl3/HBr system works via two separate catalytic cycles that are connected by radical species. It is found that preparing azo compounds through catalytic oxidation of corresponding hydrazo precursors were highly efficient and corresponds a valuable addition to the chemistry of azo compounds.

Reports on a system that allows direct observation of oxidative addition of a strong unactivated carbon-carbon bond to a metal complex in solution, including isolation and crystallographic characterization of the insertion product.

Mixtures of 1,3,5-trinitroso-1,3,5-triazinane (TMTA) with 1,3,5-trinitro-1,3,5-triazinane (RDX), cis-1,3,4,6-tetranitro-octahydroimidazo-[4,5-d]imidazole (BCHMX) and ɛ-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20), respectively, have been investigated by DSC and TGA techniques. It has been found that there are two endothermic peaks at about 96 °C and 107 °C, due to polymorphic transition and melting of TMTA, whereas only small endothermic peaks were observed in the temperature region of 92.8–95.0 °C for mixtures of RDX-TMTA, BCHMX-TMTA and CL-20-TMTA. These differences in exothermic temperatures of the pristine TMTA versus its mixtures could be a result of co-crystals formation. Moreover, only one complex step for decomposition of TMTA and RDX-TMTA was observed, while at least two steps were found for BCHMX-TMTA and CL-20-TMTA mixtures. TGA measurements showed that a mass loss of TMTA begins at 89.3 °C and has a peak temperature of 185.9 °C. In contrast, the mass loss of RDX-TMTA mixture begins at 142.9 °C and has a peak temperature of 227.6 °C, evidently showing a behavior of a single compound. On the other hand, the activation parameters for the first step decomposition of the BCHMX-TMTA (2.355 J g −1 ) and CL-20-TMTA mixtures were found to be very close to that of TMTA (1.320 J g −1 ), strongly indicating that most probably TMTA undergoes decomposes during the first decomposition steps of these mixtures. [ABSTRACT FROM AUTHOR]

Control over molecular scale electrical properties within nano junctions is demonstrated, utilizing site-directed C60 targeting into protein macromolecules as a doping means. The protein molecules, self-assembled in a miniaturized transistor device, yield robust and reproducible operation. Their device signal is dominated by an active center that inverts affinity upon guest incorporation and thus controls the properties of the entire macromolecule. We show how the leading routes of electron transport can be drawn, spatially and energetically, on the molecular level and, in particular, how the dopant effect is dictated by its "strategic" binding site. Our findings propose the extension of microelectronic methodologies to the nanometer scale and further present a promising platform for ex situ studies of biochemical processes. [ABSTRACT FROM AUTHOR]

A series of new adamantyl-oligoethyleneglycol-fullerene hybrids was prepared via Bingel-Hirsch functionalization of the C60 fullerene with various adamantyl-oligoethyleneglycol malonates. As NMDA-targeted antioxidants, these compounds may have the potential to be developed as therapeutic agents for the treatment of neurological disorders. [ABSTRACT FROM AUTHOR]

The development of halogen-free nitramine-based green solid propellants has attracted a significant interest due to their application in rapidly developing aerospace technologies. However, relatively low burn rates, and generation of high pressure in the combustion chamber limit applications of such propellants. The alleviation of these problems could be achieved by using suitable combustion catalysts. Herein, a new energetic nitrogen-rich open framework compound 1 was prepared and evaluated as an efficient Pb-free combustion catalyst for HMX-nitrocellulose-nitroglycerin solid composite propellant formulation. Compound 1 was synthesized by a straightforward one-step process, its structure was comprehensively characterized by x-ray crystallography, and it was found to be thermostable (decomposition at 289 °C), insensitive to mechanical impact and friction (60 J, 360 N), and showed high hydrolytic stability. A propellant formulation containing 3.0 wt.% of 1 exhibited 45% increase in its burning rate (under 6.0 MPa) versus catalyst-free reference propellant. In the pressure range of 3–10 MPa, the pressure exponent was calculated to be 0.32, which is more than two times lower than of the reference propellant. These impressive properties of catalyst 1 suggest that it has a great potential to be further used in the development of future highly energetic green solid propellants. [ABSTRACT FROM AUTHOR]

A method of synthesizing stable chiral Ag nanoparticles inside a natural mucin glycoprotein is demonstrated. The reaction is carried out without the help of an external reducing agent, by utilizing the reducing properties of the host mucin. A chiral spectrum is detected in the visible range, indicating the formation of a new type of chiral Ag nanoparticles-containing biomaterial. [ABSTRACT FROM AUTHOR]

Subcritical water hydrolysis and carbonization of the biomass are an emerging green technology for seaweed biomass processing. In this work, a novel approach for co-generation of two energy streams from seaweed biomass (fermentable sugars and solid hydrochar) with subcritical water from a green macroalgae Ulva sp. was developed. It was found that for the released of glucose, xylose, rhamnose, fructose, and galactose, the process temperature is the most significant parameter, followed by salinity, solid load, and treatment time. For the formation of fermentation inhibitor 5-hydroxymethylfurfural (5-HMF), temperature also was the most important parameter, followed by residence time, salinity, and solid load. The optimum parameters for maximal release of total sugars under minimum formation of 5-HMF were 170 °C (800 kPa abs.), 5% solid loading, 40 min residence time, and 100% salinity. The hydrochar yield was 19.4% and hydrochar high heating value was 20.2 ± 1.31 MJ kg−1. These results provide new detailed information on the subcritical hydrolysis and carbonization of Ulva sp. biomass and show co-production of fermentable monosaccharides and hydrochar. [ABSTRACT FROM AUTHOR]

Epoxy resins have a wide range of applications, including in corrosion protection of metals, electronics, structural adhesives, and composites. The consumption of epoxy resins is predicted to keep growing in the coming years. Unfortunately, thermoset resins cannot be recycled, and are typically not biodegradable. Hence, they pose environmental pollution risk. Here, we report degradation of epoxy resin by two bacteria that are capable of using epoxy resin as a sole carbon source. These bacteria were isolated from soil samples collected from areas around an epoxy and polyurethanes manufacturing plant. Using an array of molecular, biochemical, analytical, and microscopic techniques, they were identified as Rhodococcus rhodochrous and Ochrobactrum anthropi. As epoxy was the only carbon source available for these bacteria, their measured growth rate reflected their ability to degrade epoxy resin. Bacterial growth took place only when the two bacteria were grown together, indicating a synergistic effect. The surface morphology of the epoxy droplets changed significantly due to the biodegradation process. The metabolic pathway of epoxy by these two microbes was investigated by liquid chromatography mass spectrometry. Bisphenol A, 3,3′-((propane-2,2-diylbis(4,1-phenylene))bis(oxy))bis(propane-1,2-diol) and some other constituents were identified as being consumed by the bacteria. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Macroalgae as carbon source for polyhydroxyalkanoate accumulation in Haloferax mediterranei. • Utilization of Ulva sp. hydrolysate for PHA production with halophilic archaea. • Application of extreme halophilic archaea for PHA production. • Seagriculture for sustainable PHA production. Abstract Non-conventional carbon sources, such as macroalgae, are sustainable alternatives for large-scale production of biopolymers. The present study examined macroalgae-derived carbohydrates, as carbon sources for the production of polyhydroxyalkanoates (PHAs) by Haloferax mediterranei. Simulants of the hydrolysates of seven different macroalgal biomasses were prepared and the PHA production was studied. A maximum biomass concentration with maximum PHA content was detected in medium prepared from green macroalgae. The highest cell dry weight and PHA concentrations were 3.8 ± 0.2 g·L−1 and 2.2 ± 0.12 g·L−1 respectively when Haloferax mediterranei was grown in 25% (w/w) of Ulva sp. hydrolysate, at 42 °C temperature and initial pH of 7.2. Poly(3-hydroxy-butyrate-co-3-hydroxyvalerate was the major PHA constituent. The present study demonstrated that Ulva sp. is a promising feedstock for PHA production. [ABSTRACT FROM AUTHOR]

Development and molecular engineering of new highly-efficient energetic biocidal materials is a significant challenge and of a great importance. Until now this type of materials included mostly halogen-rich nano-thermites and iodine-rich organic materials. So far, no energetic coordination polymers were reported as precursors for combustion-generated biocidal agents. Here, we demonstrate for the first time the synthesis of uniquely-structured three-dimensional energetic coordination polymer ( ECP3 ) containing Zn metal centers and iodine- and nitrogen-rich bridging ligand ( 2 ). Upon its combustion, ECP3 is capable of generating gaseous reactive iodine species and elemental iodine-coated ZnO particles. ECP3 presents a novel approach for the design of efficient biocidal agents. [ABSTRACT FROM AUTHOR]

Graphical abstract The Diaminotriazole group has great effect on the physical models and activation energies of the initial decomposition of tetrazine derivatives. Highlights • The heat flow behaviour of three insensitive and thermostable s -tetrazine derivatives was evaluated. • The mass loss properties of these compounds were compared with DSC results. • Their decomposition kinetic parameters and physical models were determined. • The gaseous products were analyzed with proposed initial thermolysis mechanisms. Abstract The thermal behaviour, decomposition kinetics and mechanisms of three diaminotriazole-substituted tetrazine compounds have been investigated using simultaneous DSC-TG and TG/MS techniques. It has been found that TBDM-2NB is much more stable than TBDM-NB and TBDM, where the latter decomposes in two steps with different kinetic parameters. The TBDM decomposes with peak temperature of 379.0 °C, while it is 355.6 °C and 386.5 °C for TBDM-NB and TBDM-2NB, respectively. The activation energy of the first step of TBDM is much higher (176.2 kJ mol−1) than the second step (102.3 kJ mol−1). The decomposition of TBDM-NB follows 2-d diffusion model, while it is a first order reaction model for TBDM and nucleation growth model for TBDM-2NB. The rearrangement of s-tetrazine ring is typical for thermal decomposition of the title compounds, which may undergo a homo-scission to produce N 2 and followed by production of NH 3. [ABSTRACT FROM AUTHOR]

The avocado processing industry produces up to 1.3M tons of agro-waste annually. Chemical analysis of avocado seed waste (ASW) revealed that it is rich in carbohydrates (464.7 ± 21.4 g kg−1) and proteins (37.2 ± 1.5 g kg−1). Optimized microbial cultivation of Cobetia amphilecti using an acid hydrolysate of ASW, generated poly(3-hydroxybutyrate) (PHB) in a 2.1 ± 0.1 g L−1 concentration. The PHB productivity of C. amphilecti cultivated on ASW extract was 17.5 mg L−1 h−1. The process in which a novel ASW substrate was utilized has been further augmented by using ethyl levulinate as a sustainable extractant. This process achieved 97.4 ± 1.9 % recovery yield and 100 ± 1 % purity (measured by TGA, NMR, and FTIR) of the target PHB biopolymer, along with a high and relatively uniform PHB molecular weight (M w = 1831 kDa, M n = 1481 kDa, M w /M n = 1.24) (measured by gel permeation chromatography), compared to PHB polymer extracted by chloroform (M w = 389 kDa, M n = 297 kDa, M w /M n = 1.31). This is the first example of ASW utilization as a sustainable and inexpensive substrate for PHB biosynthesis and ethyl levulinate as an efficient and green extractant of PHB from a single bacterial biomass. [Display omitted] • Avocado seed waste (ASW) was found to be a novel carbohydrate-rich source. • ASW was found as an efficient substrate for poly(3-hydroxybutyrate) (PHB) production. • Ethyl levulinate is a novel, cost-effective, and sustainable PHB extraction solvent. • High PHB recovery yield (~97 %) and purity (~100 %) were obtained. • High and uniform M w (1830 kDa, M w /M n = 1.23) PHB polymer was recovered. [ABSTRACT FROM AUTHOR]

Several new photosensitive, yet mechanical insensitive energetic coordination hybrid crystals (ECHCs) containing nano-sheets of carbohydrazide functionalized graphene oxide (GO-CHZ), as a doping agent, were prepared and comprehensively characterized. It has been demonstrated that the transition metal centers in ECHCs are 6-coordinated with the GO-CHZ and CHZ as coligands. The SEM analyses show that the GO-CHZ-CuN-1 ECHC has irregular shapes, while its cobalt and nickel analogues are homogeneous crystalline embedded with layered GO-CHZ nano-sheets. Powder X-ray diffraction study indicates that the type of metals and doping of GO-CHZ would not change the space group and symmetry of the crystals of ECHCs. The doping of CHZ-CoP and CHZ-NiP by GO-CHZ significantly improves their impact sensitivity (from 1.0 J to over 10 J). Notably, by using GO-CHZ as a doping agent, the ignition delay of CHZ-CoP was also greatly improved (only 214 μs for GO-CHZ-CoP-3), which is much shorter than that of pristine CHZ-CoP (401 μs), even though the latter used a laser with 30 times higher energy density. It indicates that these new materials are highly attractive for future smart laser-ignition systems. [ABSTRACT FROM AUTHOR]

A series of new nitrogen-rich energetic salts containing 1 H ,1′ H -[5,5′-bitetrazole]-1,1′-diol (BTO) anion and ethane-1,2-diaminium ( 1 ), 1-amino-1 H -1,2,3-triazol-3-ium ( 2 ), 4-amino-4 H -1,2,4-triazol-1-ium ( 3 ) and 4,5-diamino-4 H -1,2,4-triazol-1-ium ( 4 ) cations were synthesized by direct salt formation or by metathesis strategy. The structures of energetic salts 1 - 4 were comprehensively characterized by elemental analysis, mass spectrometry, IR and NMR spectroscopies and by X-ray crystallography. DSC and TGA methods were used to study thermal properties of these salts. Additionally, the non-isothermal kinetic parameters and thermodynamic parameters were calculated by utilizing the Kissinger's and Ozawa-Doyle's methods. The enthalpies of formation for all target compounds in this study were calculated, and their sensitivity to mechanical impact and friction was tested according to BAM guidelines. We found these new energetic salts exhibit good thermal stability and have typical decomposition temperatures above 230 °C, except for the salt 2 . All our salts have highly-positive enthalpies of formation (311.1–473.6 kJ mol − 1 ) and are insensitive to impact and friction stimuli (>40 J, 120 N). With a high nitrogen-rich content, high enthalpy of formation, good thermostability and very low sensitivity to impact, some of these new salts may have a potential for application in the field of environmentally friendly insensitive energetic materials. [ABSTRACT FROM AUTHOR]

A simple method for the synthesis of nanoparticles (NPs) of silver (Ag) in a matrix of bovine submaxillary mucin (BSM) was reported previously by some of the authors of this study. Based on mucin characteristics such as long-lasting stability, water solubility, and surfactant and adhesive characteristics, we hypothesized that these compounds, named BSM-Ag NPs, may possess favorable properties as potent antimicrobial agents. The goal of this study was to assess whether BSM-Ag NPs possess antibacterial activity, focusing on important plant-pathogenic bacterial strains representing both Gram-negative (Acidovorax and Xanthomonas) and Grampositive (Clavibacter) genera. Growth inhibition and bactericidal assays, as well as electron microscopic observations, demonstrate that BSM-Ag NPs, at relatively low concentrations of silver, exert strong antimicrobial effects. Moreover, we show that treatment of melon seeds with BSM-Ag NPs effectively prevents seed-to-seedling transmission of Acidovorax citrulli, one of the most threatening pathogens of cucurbit production worldwide. Overall, our findings demonstrate strong antimicrobial activity of BSM-Ag NPs and their potential application for reducing the spread and establishment of devastating bacterial plant diseases in agriculture. [ABSTRACT FROM AUTHOR]

A series of nitrogen-rich energetic salts of 1,1′-dinitramino-5,5′-bistetrazolate (DNABT) guanidinium ( 1), aminoguanidinium ( 2), diaminoguanidinium ( 3), triaminoguanidinium ( 4), diaminouronium ( 5), 3,4-diamino-1,2,4-triazolium ( 6), and ethylenediammonium ( 7) was synthesized by a metathesis strategy and characterized by elemental analysis, mass spectrometry, and IR spectroscopy as well as single-crystal X-ray diffraction and differential scanning calorimetry (DSC). The natural bond orbitals (NBOs) and electrostatic potentials (ESPs) were further computed for a better understanding of the structures of the DNABT molecule. The heats of formation were calculated based on the Born-Haber energy cycle. The detonation parameters were evaluated by using the EXPLO5 program, and the sensitivities were measured according to BAM standers. These new salts exhibit highly positive heats of formation (407.0-1377.9 kJ mol−1) and good thermal stabilities (180-211 °C). Most of these compounds possess detonation velocities comparable to RDX and acceptable detonation pressures. The high volumes of explosion gases of the salts 3 and 4 (921 and 933 L kg−1, respectively) further support their power as explosives. The enhancing performances, the fact of being free of metals, and the more moderate sensitivities than K2DNABT, suggest that the salts 4 ( D=8851 m s−1, P=29.0 GPa), 5 ( D=9053 m s−1, P=32.3 GPa), and 6 ( D=8835 m s−1, P=30.2 GPa) might be potential environmentally friendly energetic materials. [ABSTRACT FROM AUTHOR]

• Novel hypergols with H 2 O 2 -HAN oxidizer formulations were prepared and evaluated. • Top performing hypergol showed ID time of 4 ms with HAN-H 2 O 2 , even at −40 °C. • Stability of 15N-labeled HAN in H 2 O 2 was studied by multinuclear NMR and DSC. • Based on UV–vis and EPR studies, a mechanism of hypergolic reaction was proposed. • Ignition and combustion studies were conducted using a custom-made hybrid motor. Development of fully green hybrid propulsion systems, in which both the oxidizer and the fuel are environmentally benign, while having a desirable performance under in-space conditions, is a formidable challenge. Herein, we present new air-stable solid propellants capable of exhibiting hypergolic ignitions with commercially available H 2 O 2 (70 %) and its low-freezing formulation containing hydroxylammonium nitrate (HAN). A top performing Janus-type fuel 15 showed remarkable ignition delay time of 4 ms with HAN-H 2 O 2 formulation, even at −40 ℃. The Janus-type design approach allowed modulation of the ignition delay times by varying the carbon chain-length, the type of the used transition metals and the molecular structure of the resulted solid fuels. Studies of HAN and related salts formulations with H 2 O 2 allowed us to get an insight into the reasons of the stability of HAN-H 2 O 2 formulations. UV–vis and EPR monitoring of selected fuels reactions with oxidizers, as well as surface wettability measurements, provided a valuable information related to the better understanding of the hypergolic reaction mechanisms, which should contribute to the design of the next generation of green hypergolic propulsion systems. We also successfully tested fuel 15 in a custom-made small-scale static hybrid motor system, injecting H 2 O 2 in a sequence of pulse or in continuous flow modes. [ABSTRACT FROM AUTHOR]

Tetrazolone (5-oxotetrazole) was synthesized by a moderate strategy through three steps (addition, cyclization and catalytic hydrogenation) avoiding the unstable intermediate diazonium, as reported during the previous preparation. Alkali and alkaline earth metal salts with lithium (1), sodium (2), potassium (3), rubidium (4) caesium (5), magnesium (6), calcium (7), strontium (8) and barium (9) were prepared and fully characterized using elemental analysis, IR and NMR spectroscopy, DSC and TG analysis. All metal salts were characterized via single-crystal X-ray diffraction. They crystallize in common space groups with high densities ranging from 1.479 (1) to 3.060 g cm−3 (5). Furthermore, the crystal structures of 7, 8 and 9 reveal interesting porous energetic coordination polymers with strong hydrogen bond interactions. All new salts have good thermal stabilities with decomposition temperature between 215.0 °C (4) and 328.2 °C (7), significantly higher than that of the reported nitrogen-rich salt neutral tetrazolone. The sensitivities towards impact and friction were tested using standard methods, and all the tetrazolone-based compounds investigated can be classified into insensitive. The flame test of these metal salts supports their potential use as perchlorate-free pyrotechnics or eco-friendly insensitive energetic materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • A microwave sensitive nanothermite was prepared by doping of Al/CuO with MXene. • The composites' microwave ignition power and delay time were significantly reduced. • The combustion and ignition performance of composites could be modulated by MXene. Nanothermites have a wide application in many civil and defense applications, including propulsion and detonations systems, micro-electromechanical (MEMs) and other systems that require fast energy release rate and low ignition temperature. Traditional ignition methods are commonly based on surface excitation (spot ignition), possessing a risk of undesired ignition. Safe and selective microwave (MW)-based igniting systems can interact with an ignitable material (typically a thermite) over its full volume at once. Unfortunately, thermites have low susceptibility to MW due to the presence of Al 2 O 3 oxide shell on Al particles, which would commonly require a high ignition power of MW radiation and long ignition delay times. In this work, Ti 3 C 2 MXene was introduced as a MW susceptor into Al/CuO energetic nanocomposites. The samples were ignited using a MW probe, showing that the introduction of MXene into Al/CuO/MXene could significantly reduce the power required for its MW ignition, as well as shorten the ignition delay time versus the parent Al/CuO nanothermite. Besides, presence of MXene could modulate and control a heat release, gas production and combustion performance of the Al/CuO/MXene composites, substantially extending safety, flexibility and adaptability of new nanothermites to various operational requirements. [ABSTRACT FROM AUTHOR]

New highly energetic coordination polymers (ECPs), based on the graphene oxide (GO)-copper(II) complex, have been synthesized using 5,5′-azo-1,2,3,4-tetrazole (TEZ) and 4,4′-azo-1,2,4-triazole (ATRZ), as linking ligands between GO-Cu layers. The molecular structures, sensitivity, and detonation performances of these ECPs were determined. It was shown that these energetic nanomaterials are insensitive and highly thermostable, due to high heat and impact dissipation capacity of GO sheets. In particular, the GO-TEZ-Cu(II) ECP shows low sensitivity to impact and electrostatic discharge (Im = 21 J; ESD of 1995 mJ) and has a comparable detonation performance to RDX. Also, our novel GO/Cu(II)/ATRZ hybrid ECP GO-Cu(II)-ATRZ ECP exhibits high density (2.85 g·cm-3), remarkably high thermostability (Tp = 456 °C), and low sensitivity (Im > 98 J; ESD of 1000 mJ). The latter material has a calculated detonation velocity of 7082 m·s-1, which is slightly higher than that of energetic ATRZ-Cu(II) 3D MOF and higher than one of the top thermostable explosives HNS (Tp = 316 °C; 7000 m s-1). [ABSTRACT FROM AUTHOR]

• Novel sulfur-containing laser-ignitophores were prepared and evaluated. • Sulfur atoms integration significantly improves thermostability and sensitivity. • Compound C7 exhibited low-power laser ignitability with ignition delay time of 11 ms. • Crystal-level TD-DFT and ab initio molecular dynamics calculations were performed. • A mechanism of sequential multi-photon absorption conversion into heat was proposed. The chemistry of lead-, azide- and perchlorate-free photosensitive energetic materials suitable for laser-ignition systems is an emerging field of research with a broad range of applications. To develop less toxic materials that would be sufficiently thermostable, safe, and sensitive enough to be ignited by low-power laser, is a formidable challenge. In this work, we designed, prepared, and studied properties of new sulfur-containing energetic molecules (SEMols), based on novel N -(1,3,4-thiadiazol-2-yl)nitramide explosophore. Newly synthesized energetic compounds N -(5-nitro-1,3,4-thiadiazol-2(3 H)-ylidene)-nitramide (L1) and N 5, N 5′-dinitro-[2,2′-bi(1,3,4-thiadiazole)]-5,5′(4 H ,4′ H)-diimine (L4) were found to be more thermostable than their sulfur-free 1,3,4-oxadiazole analogues. In small-scale detonation experiments, L1 , L4 , and C7 showed better brisance than TNT. Perchlorate-free complex C7 was found to have low-power laser igniting properties, showing an ignition delay time of 11 ms and threshold ignition energy of 12.0 mJ (at 915 nm irradiation). Extensive crystal-level (328-atom super-cell) ab-initio molecular dynamics and TD-DFT calculations were performed to study the laser ignition mechanism of C7. Based on our hypothesis, this photo-thermal ignition is taking place via sequential multi-photon absorption, with energy transfer to vibrational motions in this molecule. We suggest that SEMols, such as C7 , can open a new platform for the development of novel energetic materials that have a potential for integration into laser-based safe energetic components in civil, aerospace, and defense applications. [ABSTRACT FROM AUTHOR]

The article presents a study on the function of mucin glycoproteins in promoting organic reactions. The study reveals that mucins is capable of accelerating organic chemical reactions which can create a natural nonenzymatic proteins. It highlights the process on how the highly reactive therapeutic agents go through the metabolic process.

Conceptually new cylindrical charges enveloped by Al foils have been designed and their thermobaric effects, due to simultaneous fragmentation and combustion of the foils, have been experimentally determined. The fragmentation processes of Al foil was supported by numerical simulations. It has been shown that the quasistatic pressures (QSP) for phlegmatized RDX (RDX ph ) enveloped with Al-coated plastic foils are higher than that of the pure RDX ph , due to combustion of these foil fragments in a thermobaric explosion. The QSP generated by Al–Ni foils enveloping RDX ph was found to be much lower than performance of other foils, possibly due to relatively inert nature of Ni. In a small detonation chamber, the charges of RDX ph /Al foil (RDX ph /Alf) produced even higher experimental maximum peak pressure (Δ p max ) than the charges that contained Al powder (Al p ). In a closed bunker, the impulse amplitudes of RDX ph enveloped by aluminized polyethylene (Al-PE) foils and RDX ph enveloped by 100 µm Alf (Alf100) charges are much lower than those of the other charges. It was found that the charges enveloped by Al foils have even larger Δ p max than that of RDX ph /Al p charges, indicating that the Alf could generate better blast performances than the Al p . The simulations indicate that the observed blast enhancement is dependent not on the thickness, but on the size of surrounding space. The thermobaric fire-ball generated by 40 g RDX/Alf charge could sustain combustion up to 40 ms, reaching a maximum radius of about 2.4 m. [ABSTRACT FROM AUTHOR]

[Display omitted] • C. amphilecti strain isolated from Ulva sp. was used for the biosynthesis of PHB. • PHB was generated from mannitol-rich agriculture wastes by C. amphilecti. • Methyl levulinate is a novel renewable and non-chlorinated PHB extraction solvent. • High recovery yield and purity of PHB were obtained with methyl levulinate solvent. The present study explored the use of mannitol and mannitol-rich agro-industrial wastes as substrates for PHB production by Cobetia amphilecti isolated from the green Ulva sp. seaweed. Cultivation of C. amphilecti on mannitol, celery, and olive leaves (OLs) waste led to 4.20, 6.00, and 5.16 g L−1 of cell dry mass (CDM), 76.3, 25.5, and 12.0% of PHB content in CDM and 3.2, 1.53, and 0.62 g L−1 of PHB concentration, respectively; which suggested that they can be exploited as carbon substrates for the production of PHB. Extraction of PHB from C. amphilecti cultures by solubilization in the green solvent methyl levulinate (ML) (2% w/w, 140 °C, 1 h) indicated that the recovery yield and purity of PHB are above 97 and 90% w/w, respectively. The use of ML could be an attractive method for the recovery of PHB when safe and non-toxic solvents are required. [ABSTRACT FROM AUTHOR]

Highlights: [•] We correlate between the nanotube curvature and the dispersion efficiency by β-lactoglobulin. [•] The nanotube changes the conformation of the dispersant β-lactoglobulin. [•] A whey protein successfully disperses carbon nanotubes. [ABSTRACT FROM AUTHOR]

Highlights: [•] New soil remediation process using phase transition of partially miscible solvents. [•] Design and synthesis of new bio-degradable, organic soluble chelating agents. [•] Feasibility tests of the process on authentically polluted sediments and sludge. [•] Simultaneous removal of toxic metals and organic pollutants was demonstrated. [Copyright &y& Elsevier]

[Display omitted] • Application of extreme halophilic archaea for PHA production. • Utilization of pneumatically agitated reactors for outdoor fermentation. • Application of ultrasonic separation technology for harvesting of archaeal biomass. • Value addition towards a halophilic biorefinery. The present study tested the outdoor cultivation of Haloferax mediterranei for PHA production from green macroalgae Ulva sp. in pneumatically agitated bioreactors and applied ultrasonic separation for enhanced settling of archaeal cells. Scaled-up cultivation (40 L) yielded maximum biomass productivity of 50.1 ± 0.11 mg·L-1·h−1 with a PHA productivity of 27 ± 0.01 mg·L-1·h−1 and conversion yield of 0.107 g PHA per gram Ulva DW. The maximum mass fraction of PHA achieved in biomass was calculated to be 56% w/w. Ultrasonic harvesting of Hfx. mediterranei cells approached 30% removal at energy inputs around 7.8 kWh·m−3, and indicated no significant aggregation enhancement by Ca2+ addition. Molecular weight analysis showed an increase in Polydispersity Index (PDI) when the corresponding air velocities were increased suggesting that the polymer was more homogeneous at lower mixing velocities. The current study demonstrated scalable processes for PHA production using Ulva sp. feedstock providing new technologies for halophilic biorefinery. [ABSTRACT FROM AUTHOR]

• Novel hydride- and boron-free, air-stable H 2 O 2 -hypergols were prepared and evaluated. • Some of these fuels have high density and showed thermostability up to 343 °C. • Top performing fuel showed Ignition Delay of 7 ms, and Specific Impulse up of 279 s. • Crystal-level DFT calculations allowed to propose Structure-Activity Relationships. • The ignition performance key factor is based on electron density on metal and ligand. The race and competition in aerospace technologies based on environmentally friendly green propulsion systems with green fuels and oxidizers are attracting a significant attention. Development of hybrid propulsion systems that use a hypergolic fuel and green H 2 O 2 oxidizer, capable of deep throttling and restarting from "cold", is a very challenging task. Here, we describe a new synthetic approach for the synthesis and characterization of conceptually new hydride- and boron-free, and air/moisture stable solid H 2 O 2 -hypergols, based on Cu and Co complexes of bis(5-tetrazolyl) amine (H 2 BTA) ligand. Among prepared and evaluated materials, the best performing compound [K 2 (H 2 O) 2 Cu(BTA) 2 ]n (JD-4) was found to exhibit short ignition delay time of 7 ms (with H 2 O 2 , 97%), and high thermostability of 343 °C. Based on obtained ignition results, X-ray crystallography and HASEM software calculations, structure-hypergolic activity-relationship studies were conducted. We found that the electron density difference between Cu and BTA units should be in a specific range (~2) for these compounds to ignite, providing a valuable tool for further development of novel, green, solid fuels for propulsion systems. [ABSTRACT FROM AUTHOR]

The nitration of chitin monomer in a mixture of nitric acid and acetic anhydride was conducted and a highly nitrated (3R,4R,6R)-3-acetamido-6-((nitrooxy)methyl)tetrahydro-2H-pyran-2,4,5-triyl trinitrate (1) was obtained. Its structure was fully characterized using infrared spectroscopy, NMR spectroscopy, elemental analysis, and X-ray diffraction. Compound 1 possesses good density (ρ: 1.721 g·cm−3) and has comparable detonation performance (Vd: 7717 m·s−1; P: 25.6 GPa) to that of nitrocellulose (NC: Vd: 7456 m·s−1; P: 23 GPa; Isp = 239 s) and microcrystalline nitrocellulose (MCNC; Vd: 7683 m·s−1; P: 25 GPa; Isp = 250 s). However, Compound 1 has much lower impact sensitivity (IS: 15 J) than the regular nitrocellulose (NC; IS: 3.2 J) and MCNC (IS: 2.8 J). Compound 1 was calculated to exhibit a good specific impulse (Isp: 240 s), which is comparable with NC (Isp: 239 s) and MCNC (Isp: 250 s). By replacing the nitrocellulose with Compound 1 in typical propellants JA2, M30, and M9, the specific impulse was improved by up to 4 s. These promising properties indicate that Compound 1 has a significant potential as an energetic component in solid propellants. [ABSTRACT FROM AUTHOR]

Abstract: A new type of gas chromatograph mass spectrometer (GC–MS) was used for semi-online monitoring of organic chemical reactions for their yield optimization, mechanism elucidation, and for obtaining information on the reaction products identity and purity. It was used with reaction mixtures without prior separation and purification as needed for NMR, thereby saving time and effort. Our unique GC–MS named 5975-SMB Supersonic GC–MS is based on GC interface with the MS with supersonic molecular beams (SMB) and on ionization of the sample molecules during their axial flight through an open electron ionization ion source as vibrationally cold molecules. GC–MS with SMB is demonstrated to significantly extend the range of compounds amenable for analysis, practically always giving molecular ions, enabling effective fast GC–MS analysis, and providing elemental formulas via isotope abundance analysis with unit mass resolution quadrupole MS. In addition, it uniquely provides uniform response to all compounds, a feature, which is vital for the measurement of chemical reaction yields. In this manuscript, four different organic synthetic reactions were studied and are described. Based on the collected data, we were able to better understand how the reaction conditions should be optimized in order to maximize the yields and purity of target products. Consequently, we propose that GC–MS with SMB can serve as a novel tool for the fast optimization of chemical reactions. [Copyright &y& Elsevier]

The catalytic reduction of nitrate by molybdo-enzymes plays a central role in the global biological cycle of nitrogen. However, the use of nitrates as oxidants in synthetic organic chemistry is very limited and typically requires very strong acidic and other extreme reaction conditions. We have developed a highly chemoselective and efficient catalytic process for the sulfoxidation of thioethers and arylthioethers containing boronic acid or boronic ester functional groups, using nitrate salts as oxidants. This homogeneous catalytic reaction was carried out in acetonitrile, where die MoO2Cl2(OPPh3)2 complex 1 or a mixture of complex 1 with Cu(NO3)2 were used as catalysts. We examined the reaction mechanism using ¹H, 15N, and 31P NMR techniques and 18O-labeled sodium nitrate (NaN18 O3) and show that the thioethers are oxidized by nitrate, generating nitrite. Our work adds to the existing chemical transformations available for organoboron compounds, providing straightforward accessibility to a variety of new substrates that could be suitable for Suzuki cross-coupling chemistry. [ABSTRACT FROM AUTHOR]

Axonal degeneration is an important determinant of progressive neurological disability in multiple sclerosis (MS). Thus, therapeutic approaches promoting neuroprotection could aid the treatment of progressive MS. Here, we used what we believe is a novel water-soluble fullerene derivative (ABS-75) attached to an NMDA receptor antagonist, which combines antioxidant and anti-excitotoxic properties, to block axonal damage and reduce disease progression in a chronic progressive EAE model. Fullerene ABS-75 treatment initiated after disease onset reduced the clinical progression of chronic EAE in NOD mice immunized with myelin-oligodendrocyte glycoprotein (MOG). Reduced disease progression in ABS-75-treated mice was associated with reduced axonal loss and demyelination in the spinal cord. Fullerene ABS-75 halted oxidative injury, CD11b+ infiltration, and CCL2 expression in the spinal cord of mice without interfering with antigen-specific T cell responses. In vitro, fullerene ABS-75 protected neurons from oxidative and glutamate-induced injury and restored glutamine synthetase and glutamate transporter expression in astrocytes under inflammatory insult. Glutamine synthetase expression was also increased in the white matter of fullerene ABS-75-treated animals. Our data demonstrate the neuroprotective effect of treatment with a fullerene compound combined with a NMDA receptor antagonist, which may be useful in the treatment of progressive MS and other neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

The syntheses of 1,10-phenanthroline fluorophore-based chemosensor 7 and its truncated analog 9 are reported. Interactions of these compounds with urea, thiourea, 1,3-dimethylurea, tetrahydropyrimidin-2(1H)-one, imidazolidin-2-one, and selected uronium salts were assessed by three-dimensional excitation-emission spectroscopy, UV-vis absorbance, and fluorescence titrations. Chemosensor 7 was found to be capable of distinguishing between neutral ureas and their salts, by producing a different optical response for each type of compounds. The complexation of urea by 7 was also studied by selective-NOE ¹H NMR, 13C NMR (using 13C-labeled guest), and MALDI-TOF mass spectrometry. In addition, we performed DFT calculations (B3LYP 3-21g** level) for structures of complexes of 7 with urea, imidazolidin-2-one, and tetrahydropyrimidin-2(1H)-one. Development of chemosensor 7-type compounds in conjunction with differential excitation-emission spectroscopy represents an important step toward the development of novel tools for ureas and their salts analysis. [ABSTRACT FROM AUTHOR]

A novel methodology for the evaluation of receptor arrangement in structurally flexible anion chemosensors was developed and applied to map the binding site of a new pseudocyclic tristhiourea chemosensor (6). The syntheses of 6 and related macrocyclic chemosensor 10 (a model of the folded monomeric structure of 6) are reported. Both chemosensors were evaluated by titration with a variety of structurally different anions in CH3CI and DMSO, showing a common preference for F-, CH3CO2-, and H2PO4-. However, within this group of anions, the binding patterns of the chemosensors differed, indicating dissimilarity in the arrangement of the binding sites of 6 and 10. [ABSTRACT FROM AUTHOR]

Abstract: Most prostate cancers are androgen dependent upon initial diagnosis. On the other hand, some very aggressive forms of prostate cancer were shown to have lost the expression of the androgen receptor (AR). Although the AR is routinely targeted in endocrine treatment, the clinical outcome remains suboptimal. Therefore, it is crucial to demonstrate the presence and activity of the AR in each case of prostate cancer, before and after treatment. While noninvasive positron emission tomography (PET) has the potential to determine AR expression of tumor cells in vivo, fully optimized PET imaging agents are not yet available. Based on molecular modeling, three novel derivatives of hydroxyflutamide (Compounds 1–3) were designed and synthesized. They contain an electron-rich group (dimethylamine) located on the methyl moiety, which may confer a better stability to the molecule in vivo. Compounds 1–3 have AR binding that is similar or higher than that of the currently used commercial drugs. An automated carbon-11 radiolabeling route was developed, and the compounds were successfully labeled with a 10–15% decay-corrected radiochemical yield, 99% radiochemical purity and a specific activity of 4Ci/μmol end of bombardment (n=15). These labeled biomarkers may facilitate the future quantitative molecular imaging of AR-positive prostate cancer using PET and may also allow for image-guided treatment of prostate cancer. [Copyright &y& Elsevier]

Abstract: Approximately 80–90% of prostate cancers are androgen dependent at initial diagnosis. The androgen receptor (AR) is present in most advanced prostate cancer specimens and is believed to have a critical role in its development. Today, treatment of prostate cancer is done by inhibition of AR using antiandrogens such as flutamide (pro-drug of hydroxyflutamide), nilutamide, and bicalutamide. However, there is currently no noninvasive imaging modalities to detect, guide, and monitor specific treatment of AR-positive prostate cancer. (R)-3-Bromo-N-(4-fluoro-3-(trifluoromethyl)phenyl)-2-hydroxy-2-methyl-propanamide [ 18 F]-1 and N-(4-fluoro-3-(trifluoromethyl)phenyl)-2-hydroxy-2-methylpropanamide [ 18 F]-2, derivatives of hydroxyflutamide, were synthesized as a fluorine-containing imaging agent candidates. A three-step fluorine-18 radiosynthesis route was developed, and the compounds were successfully labeled with a 10±3% decay corrected radiochemical yield, 95% radiochemical purity, and a specific activity of 1500±200Ci/mmol end of bombardment (n =10). These labeled biprobes not only may enable for the future quantitative molecular imaging of AR-positive prostate cancer using positron emission tomography but may also allow for image-guided treatment of prostate cancer. [Copyright &y& Elsevier]

• Exploring Polyhydroxyalkanoats production by green seaweed associative bacteria. • Ulva sp. hydrolysates as a substrate for PHA production by microbial isolates. • New Cobetia isolates afforded high PHA production, 61% (w/w) This work aimed to isolate a series of bacterial strains associated with the green seaweed Ulva sp. and evaluate their capability to manufacture PHA. The effect of the type of supplemented sugars found to be in macroalgae, on the growth and PHA productivity of the strains was studied. Analysis of the 16S rRNA gene sequence of the isolated strains revealed that the PHA-producing bacteria were phylogenetically related to the genus Cobetia , Bacillus , Pseudoaltermonas and Sulfitobacter, which showed high PHA contents among the isolates. The highest PHA content was observed in the case of Cobetia strain, with up to 61% w/w in the presence of mannitol and 12% w/w on Ulva sp. acid hydrolysate as a substrate. [ABSTRACT FROM AUTHOR]

• Hydrothermal processing of the whole Ulva sp. biomass vs. extracted carbohydrate fractions of starch and cellulose. • Glucose is a major released monosaccharide with hydrothermal deconstruction. • Most of the glucose is released from starch. • Whole biomass hydrolysis preferred for PHA fermentation with Haloferax mediterranei. • The highest ash-free hydrochar yield was from Ulva cellulose. In the fermentation and bioenergy industry, terrestrial biomass is usually fractionated and the collected components, such as starch, are processed separately. Such a separation has not been reported for seaweeds. In this work, the direct hydrothermal processing of the whole green seaweed Ulva sp. biomass is compared to processing of separated starch and cellulose, to find the preferable route for monosaccharide, hydrochar, and polyhydroxyalkanoates (PHA) production. Glucose was the major released monosaccharide. A significant share of the glucose yield comes from the starch fraction. The highest hydrochar yield with the lowest ash content was obtained from the separated cellulose fraction. The highest PHA yield was obtained using a whole Ulva sp. hydrolysate fermentation with Haloferax mediterranei. Economic analysis shows the advantage of direct Ulva sp. biomass fermentation to PHA. The co-production of glucose and hydrochar does not add significant economic benefits to the process under plausible prices of the two outputs. [ABSTRACT FROM AUTHOR]

• Tea polyphenols are used as an interfacial layer to tailor the structured iodine-based MICs. • The modified MIC shows enhanced thermal reactivity and energy release. • The improved combustion efficiency and burning rate have been demonstrated. It has been demonstrated in this paper that the tea polyphenols (TP) can easily adhere to the surface of particles through self-polymerization, even these particles are very hydrophobic. In this paper, a method of in-situ polymerization of TP has been used to coat n-Al powder. Then, Bi(IO 3) 3 crystal is grown on TP as an interfacial layer to obtain core-shell iodine-based MICs (n-Al@TP@Bi(IO 3) 3). Various characterization techniques are used to investigate the prepared core-shell MICs, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermal analysis, mass spectrum (MS), bomb calorimetry and high-speed camera. The results show that the obtained novel MICs are uniformly and densely distributed. The n-Al@TP@Bi(IO 3) 3 has higher reactivity and heat release than the traditional mechanical mixture, and the initial reaction temperature is reduced by about 30 °C caused by the decomposition-promoting effect of the decomposition product of TP (carbon) on Bi(IO 3) 3. and the volume reaction heat of n-Al@TP@Bi(IO 3) 3 (21.246 kJ cm−3) enhances by 11.3%. The results of combustion experiments show that the burning rate of n-Al@TP@Bi(IO 3) 3 is above 3.4 m s−1, which is 4 times that of Al/ Bi(IO 3) 3 (0.9 m s−1). Moreover, the combustion efficiency is higher and the agglomeration of the condensed combustion products is greatly decreased. Various other core-shell structured MICs with tunable reactivity could be easily prepared by using similar interfacial binding materials by using our strategy as a guidance. [ABSTRACT FROM AUTHOR]

Due to a significant and prolific activity in the field of design and synthesis of new energetic molecules, it becomes increasingly difficult to introduce new explosophore structures with attractive properties. In this work, we synthesized a trans-bimane-based energetic material—3,7-diamino-2,6-dinitro-1H,5H-pyrazolo-[1,2-a]pyrazole-1,5-dione (4), the structure of which was comprehensively analyzed by a variety of advanced spectroscopic methods and by X-ray crystallo-graphy (with density of 1.845 g·cm−3 at 173 K). Although obtained crystals of 4 contained solvent molecules in their structure, state-of-the-art density functional theory (DFT) computational techniques allowed us to predict that solvent-free crystals of this explosive would preserve a similar tightly packed planar layered molecular arrangement, with the same number of molecules of 4 per unit cell, but with a smaller unit cell volume and therefore higher energy density. Explosive 4 was found to be heat resistant, with an onset decomposition temperature of 328.8 °C, and was calculated to exhibit velocity of detonation in a range of 6.88–7.14 km·s−1 and detonation pressure in the range of 19.14–22.04 GPa, using for comparison both HASEM and the EXPLO 5 software. Our results indicate that the trans-bimane explosophore could be a viable platform for the development of new thermostable energetic materials. [ABSTRACT FROM AUTHOR]

Although the negative consequences of the global phenomenon of jellyfish (JF) swarms are well recognized, the use of their biomass for practical applications is mostly limited to a niche in the Asian food industry. This fact is quite surprising since JF's biomass comprises useful biomaterials such as Q‐mucin glycoprotein and collagen. In this work, the JF biomass, collected from two different species, is used to prepare electrospun scaffolds composed of nanometric "core–shell"‐type fibers, in which adjustment of the electrospinning process parameters can easily control their mechanical, morphological, and chemical properties. This nonwoven scaffold shows excellent biocompatibility and biodegradability, indicating suitability for biomedical research contexts. Performed cell proliferation assays show that the scaffold could support the growth of cardiac cells, fitting the requirement of tissue engineering. Additional incorporation of in situ‐generated silver nanoparticles in these nanofibers produced mats with potent antibacterial properties. Preclinical trials with the resulted mats on porcine wound healing models exhibit fast and complete healing of wounds. [ABSTRACT FROM AUTHOR]