Divalent nitrogen-rich cationic salts with great gas production capacities

Monocyclic nitrogen-rich 3-(aminomethyl)-4,5-diamine-1,2,4-triazole(1)and fused cyclic 3,7-diamine-6-(aminomethyl)-[1,2,4]triazolo[4,3-b][1,2,4]triazole(9)were synthesized through the convenient cyclization reaction from the readily available reactant.Their energetic salts with high nitrogen content were proved to be rare examples of divalent monocyclic/fused cyclic cationic salts according to the single crystal analyses.The structure of intermediate B was also identified and verified by its trivalent cation crystal 17.5H_2O indirectly.Energetic compounds 2-8 and 10-17 were fully characterized by NMR spectroscopy,infrared spectroscopy,differential scanning calorimetry,elemental analysis.These energetic salts exhibit good thermal stability with decomposition temperatures ranged from 182℃to 245℃.The sensitivity of compounds 2,6,10 and 14 is similar or superior to that of RDX while the others were much more insensitive to mechanical stimulate.Furthermore,detonation velocity of 10(8843 m/s)surpass that of RDX(D=8795 m/s).Considering the high gas production volume(≥808 L/kg)of 2,4,10and 12,constant-volume combustion experiments were conduct to evaluate their gas production capacities specifically.These compounds possess much higher maximum gas-production pressures(P_(max):7.88-10.08 MPa)than the commonly used reagent guanidine nitrate(GN:P_(max)=4.20 MPa),which indicate their strong gas production capacity.

A Theoretical Study of Tris-(o-benzoquinonediimine)-First-Row Divalent Transition Metal Complexes

The ligand o-phenylenediamine (opda) and its oxidized form, o-benzoquinonediimine (bqdi), act as a fascinating candidate coordinating toward transition metal ions leading to the photochemical hydrogen production in absence of photosensitizers. Herein, we report the systematic study of the interaction between the oxidized form bqdi ligand, tris-(o-benzoquinonediimine) with divalent first-row transition metal series using DFT calculations. The lowest energy structures, bond length, binding energies, frontier molecular orbital analysis, natural bond orbitals, and global reactivity descriptor were calculated using B3LYP/6-311G(d,P) level of theory. The time dependent-DFT at the CAM-B3LYP/6-311+G(d,p) level of theory was applied to determine the electronic structures and the optical spectra. The theoretical binding trend of the divalent first-row transition metal series is decreasing as follows: Cu >Ti > V > Co > Ni > Fe > Cr > Zn >Mn. Among them, the binding potency of iron (II) by the bqdi ligand was not predominantly sturdy as compared to other first-row divalent transition metal ions. The origin of strong coordination with Fe(II) is attributed to its extra capability to induce covalent coordination of bqdi ligands. The complex exhibited two strong peaks at 370 nm and 452 nm, due to the HOMO-3 to LUMO+1 and HOMO-1 to LUMO transitions, respectively. Natural bond orbital analysis showed that the major interaction happens between the N lone pair electrons of the ligand with an anti-bonding orbital of metal ions, in which Ti showed the highest interaction energy than other metal ions. The present systemic DFT study of bqdi ligands with the first-row transition metals strongly encourages the future establishment of photochemical hydrogen production in absence of photosensitizers.

Polymerization of Phenyl Isocyanate by Divalent Samarium Complex (ArO)_2Sm(THF)_4 (ArO=2,6-di-tert-butyl-4-methylphenoxo)

Phenyl isocyanate was for the first time successfully polymerized by divalent samarium complex (ArO)2Sm(THF)4. The monomer concentration and temperatur affected the polymerization greatly.

SYBR Green I-based product-enhanced reverse transcriptase assay for quantification of retroviral PFV and detection of the divalent cation preference of PFV RT

Dear Editor,Prototype foamy virus(PFV)belongs to the genus Spumavirus in the Spumaretrovirinae subfamily of Retroviridae.Although PFV and HIV have much in common,research into PFV has lagged far behind that into HIV,as PFV appeared to be non-pathogenic both in accidentally infected humans and in experimentally infected animals.In recent decades,however,more attention has been focused on PFV because it seems to

EFFECTS OF COMPOSITION AND STRUCTURE OF ALGINATES ON ADSORPTION OF DIVALENT METALS

Results of a series of experiments（on the adsorption of divalent metal ions by dried alginic acid, Na and Ca alginates of different composition and block structure） conducted in this systematic study of the effects of the composition and structure of alginates on the static adsorption equilibrium of divalent metal ions indicate that the properties of alginate adsorption to divalent metal ions are highly different, depending not only on the cations used, but also on the form and structure of the alginates. There is close correlation between the adsorption properties and the structure of the alginates. The selectivity coefficient of Na alginate for Cd-Sr ion exchange tends to increase with the increase of the M/G ratio in alginate, whereas the adsorption capacity of Ca alginate for Cu2+ ion decrease with the increase of the G-block or the average length of the G-block （（?）G） and the total adsorption capacity of alginic acid is found to vary in the same order as the FMM（diad frequency） in alginate

Syntheses of Divalent Rare Earth Ternary Halides KYbBr_(3), KYbCl_(3), KSm_(2)Br_(5), KSm_(2)C_(l5), KEu_(2)C_(l5) by Alkalimetallothermoreduction

Introduction CsEuF3, CsYbF3 and RbYbF3 are the first members of divalent rare earth ternary halides obtained via reduction of trivalent rare earth halides by alkali metals. Recently we adopted a new synthesis route in preparing divalent rare earth chlorides and bromides and the five titled compounds were suc-

Prediction of Enthalpies of Fusion for Divalent Rare Earth Halides Based on Modeling by Artificial Neural Networks and Pattern Recognition

The artificial neural network (ANN) and the pattern recognition were applied to study the correlation of enthalpies of fusion for divalent rare earth halides with their microstructural parameters,such as ionic radius and electronegativity. The model,represented by a back-propagation netal network, was trained with a 12 set of published data for divalent rare earth halides and then was used to predict the unknown ones. Also the criterion equations were ptesented to determine the enthalpies of fuSion for divalent rare earth halides using pattern recognition in mis work. The results from the model in ANN and criterion equations are in very good agreement with reference data.

Implication of Electrostatic Forces on the Adsorption Capacity of a Modified Brick for the Removal of Divalent Cations from Water

Adsorption properties of brick for the removal of divalent cations increased significantly after this material were pre-activated by HCl and subsequently impregnated with ferrihydrite. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis demonstrated that ferrihydrite was preferentially attached to clays (mainly to metakaolinite) and possessed Na atoms at levels higher than those observed in iron-poor aggregates. Sodium is bound to hydroxyl groups which have a function as reactive sites and give rise to surface charge. Zeta potential measurements were conducted to determine the isoelectric point (IEP) and salt-addition method was used to assess the point of zero charge (PZC) of this brick. Modified brick has a positive charge in water up to pH ≈ 3.2 and negative charge above this pH. Moreover, pH was found to be the most important factor affecting the adsorption process, suggesting the possible implication of electrostatic forces at the brick-water interface. The complexation model proposed by James and Healy was applied to our system: theoretical data on free-energy changes due to effects associated both with electrostatic attraction and solvation, were found to be in agreement with those determined from kinetic experiments. Column experiments permitted further to show that adsorption reactions were strongly inhibited by addition of an inert electrolyte (like NaNO3). Under this condition, ionic strength increased and most surface sites of the brick would be occupied by Na+ ions, leading to a charge neutralization and thereby a depletion of electrostatic forces.

The Effects of Zinc and Other Divalent Cations on M-Current in Ventral Tegmental Area Dopamine Neurons

Ventral tegmental area dopamine (DA VTA) neurons are important for the reinforcing effects of drugs of abuse such as ethanol and nicotine. We have previously shown that M-current (IM) regulates the excitability of DA VTA neurons. Zinc (Zn2+) contributes to the regulation of neuronal excitation as a neuromodulator. In the present study, we investigated zinc effect on the properties of IM and the spontaneous firing frequency of DA VTA neurons. The standard deactivation protocol was used to measure IM during voltage-clamp recording with a hyperpolarizing voltage step to ﹣40 mV from a holding potential (VH) of ﹣25 mV. Zn2+ (100 μM) inhibited IM amplitude and IM recovered completely from the inhibition after the washout of Zn2+. Zn2+ inhibited IM in a concentration-dependent manner (IC50: 5.8 μM). When hyperpolarizing voltage steps were given to ﹣65 mV (in 10 mV increments) from a VH of ﹣25 mV, Zn2+ (100 μM) reduced IM amplitude at each voltage and zinc inhibition of IM was not voltage-dependent. Zn2+ increased the spontaneous firing frequency of DA VTA neurons in a concentration-dependent manner, suggesting that Zn2+ causes excitation of DA VTA neurons through an action on IM. IM of DA VTA neurons was inhibited by 100 μM divalent cations in increasing order of potency: Ba2+ (16%) 2+ (25%) 2+ (40%) 2+ (59%) 2+ (67%). These results suggest that Zn2+ may exert physiologically significant regulation of neuronal excitability in DA VTA neurons.

Synthesis of Luminescent CdTe Nanorods on Anodized Aluminum Oxide Template and Their Utility in Divalent Heavy Metal Ion Sensing

A simple one-pot hydrothermal method to grow luminescent CdTe nanorods on porous anodized aluminum oxide (AAO) template is described. These CdTe nanorods on the AAO template were further applied as an optical probe to detect divalent heavy metal ions such as Hg, Pb, Mg and Zn, by examining its photoluminescence (PL) responses. The presence of Pb and Hg ions quenched the photoluminescence (PL) of the CdTe nanorods where as Zn and Mg ions enhanced it with the effect of red shift in the peak position respectively. These PL enhancements/quenching of the nanorods after exposing to the divalent ions were explained on the basis of the active surface related recombination, which depends on the direction of carrier transfer mechanism i.e. from nanorods to the surface adsorbed metal ions or vice-versa and is attributed to the alignment of bands thus formed. The luminescent CdTe nanorods grown on AAO template was found to be effective in sensing metal ions (Pb, Hg, Zn and Mg) up to a micro-molar concentration.

Experimental Design in Solvent Extraction: A Study for Divalent Metals Separation in D2EHPA/Isoparaffin System

The solvent extraction process combined with tools of experimental design assists in developing procedures for separation and purification of elements or mineral compounds with high purity. In this work the technique was used to replace the traditional methods for the collection of basic information required for the development of a circuit of solvent extraction. According to the literature, several factors may influence the extraction of divalent metals by D2EHPA in sulfate media, among which the concentration of metals in solution. The objective was to study the variables affecting the separation process Mn/Ni/Co/Cu, such as the aqueous/organic (A/O), contact time, concentrations of the divalent metals in sulfuric medium, pH and solvent concentration. An investigation into the variables that control the process was done using a “cube + star” experimental design, with central point. The results demonstrate it is possible to obtain of a satisfactory mathematical model that describes the process.

Divalent anion intercalation and etching-hydrolysis strategies to construct ultra-stable electrodes for seawater splitting

Developing stable electrodes for seawater splitting remains a great challenge due to the detachment of catalysts at a large operating current and severe anode corrosion caused by chlorine.Herein,divalent anion intercalation and etching-hydrolysis strategies are deployed to synthesize the ultra-stable anode,dendritic Fe(OH)_(3) grown on Ni(SO_4)_(0.3)(OH)_(1.4)–Ni(OH)_(2).Experimental results reveal that the anode exhibits good activity and excellent stability in alkaline simulated seawater.After 500 h,the current density operated at 1.72 V remains 99.5%,about 210 m A cm^(-2).The outstanding stability originates from the etchinghydrolysis strategy,which strengthens the interaction between the catalyst and the carrier and retards thus the detachment of catalysts at a large current density.Besides,theoretical simulations confirm that the intercalated divalent anions,such as SO_4^(2-) and CO_(3)^(2-),can weaken the adsorption strength of chlorine on the surface of catalysts and hinder the coupling and hybridization between chlorine and nickel,which slows down the anode corrosion and improves catalytic stability.Furthermore,the twoelectrode system shows the remarkable 95.1% energy efficiency at 2,000 A m-2and outstanding stability in 6 mol L^(-1) KOH +seawater at 80 ℃.

Molecular dynamics simulations on the interactions between nucleic acids and a phospholipid bilayer

Recently,lipid nanoparticles(LNPs)have been extensively investigated as non-viral carriers of nucleic acid vaccines due to their high transport efficiency,safety,and straightforward production and scalability.However,the molecular mechanism underlying the interactions between nucleic acids and phospholipid bilayers within LNPs remains elusive.In this study,we employed the all-atom molecular dynamics simulation to investigate the interactions between single-stranded nucleic acids and a phospholipid bilayer.Our findings revealed that hydrophilic bases,specifically G in single-stranded RNA(ssRNA)and single-stranded DNA(ssDNA),displayed a higher propensity to form hydrogen bonds with phospholipid head groups.Notably,ssRNA exhibited stronger binding energy than ssDNA.Furthermore,divalent ions,particularly Ca2+,facilitated the binding of ssRNA to phospholipids due to their higher binding energy and lower dissociation rate from phospholipids.Overall,our study provides valuable insights into the molecular mechanisms underlying nucleic acidphospholipid interactions,with potential implications for the nucleic acids in biotherapies,particularly in the context of lipid carriers.

Upregulation of Divalent Metal Transporter 1 (DMT1) Is Involved in Amyloid Precursor Protein Processing and Aβ Generation

The amyloid beta precursor protein (APP) and its pathogenic byproduct β-amyloid peptide (Aβ) play central roles in the pathogenesis of Alzheimer’s disease (AD). Reduction in

Study on Divalent Organolanthanide Catalysts for Styrene Polymerization——Catalytic Activity Affected by the Substituent on the Cyclopentadienyl Ring

Divalent organosamarium and organoytterbium complexes as a kind of strong reducing agent not only can react with electron rich agents such as halides, aldehyde, ketone, unsaturated hydrocarbon and the compounds containing active hydrogen but also can catalyze hydrogenation of alkyne, ethylene polymerization and methyl methacrylate polymerization. More and more interests and attention have been given to the synthesis, structure and catalytic activity of divalent organolanthanide complexes in recent years,

EFFECTS OF DIVALENT CATIONS ON FLUIDITY AND ENZYME ACTIVITY OF H^+-ATPase-CONTAINING PROTEOLIPOSOMES

Previous studies have reported that, during reconstitution of pig heart mitochondrial H+-ATPase in soybean phospholipid liposomes by cholate dialysis method, 1mM Mg2+ in the dialysis medium greatly enhances the reconstituted enzyme activity and decreases the fluidity of the incorporating H+-ATPase proteoliposomes.

Study of Divalent Rare Earth Iodides

Properties of trivalent rare earth ions have been extensively understood. Besidesthe +3 valent state, the rare earth elements also have +4, +2 and +1 valencies,clusters and mixture valent compounds. The research of their synthesis, structure,properties of unusual valent rare earth compounds has theoretical and practicalsignificance. It will broaden the horizon of rare earth chemistry and extend

Interaction of Divalent Metal Ions with the Adenosine Triphosphate Measured Using Nuclear Magnetic Resonance

WTFZ] The interaction of adenosine triphosphate with divalent metal ions is important in biochemical functions. The effects of pH and metal ions Mg 2+ , Ca 2+ , Zn 2+ , Mn 2+ , and Co 2+ on the chemical shift of the phosphate group of ATP have been studied using Nuclear Magnetic Resonance. The chemical shift of the β-phosphate of ATP is the most sensitive to pH. Ca 2+ and Mg 2+ bind with the α- and β-phosphate groups of ATP. Zn 2+ binds to the adenosine ring hydrogen as well as to phosphate. The paramagnetic ions Mn 2+ and Co 2+ do not cause chemical shifts of the phosphate or proton peak. Mn 2+ and Co 2+ broaden the resonance peak only.[

Polyamide Nanofiltration Membrane from Surfactant-assembly Regulated Interfacial Polymerization of 2-Methylpiperazine for Divalent Cations Removal

Removal of metal ions from water can not only alleviate the scaling problem of domestic and industrial water,but also solve the water safety problem caused by heavy metal ion pollution.Here,we fabricate a positively charged nanofiltration membrane via surfactant-assembly regulated interfacial polymerization(SARIP)of 2-methylpiperazine(MPIP)and trimesoyl chloride(TMC).Due to the existence of methyl substituent,MPIP has lower reactive activity than piperazine(PIP)but stronger affinity to hexane,resulting in a nanofiltration(NF)membrane with an opposite surface charge and a loose polyamide active layer.Interestingly,with the help of sodium dodecyl sulfate(SDS)assembly at the water/hexane,the reactivity between MPIP and TMC was obviously increased and caused in turn the formation of a positively charged polyamide active layer with a smaller pore size,as well as with a narrower pore size distribution.The resulting membrane shows a highly efficient removal of divalent cations from water,of which the rejections of MgCl_(2),CoCl_(2)and NiCl_(2)are higher than 98.8%,98.0%and 98.0%,respectively,which are better than those of most of other positively charged NF membranes reported in literatures.

Emission Spectra and Crystallographic Sites of Eu^(2+) in Ca_8Zn(SiO_4)_4Cl_2

The fluorescent characteristic and emission spectra of Eu2+ in the cubic structureCa8Zn（SiO4）4Cl2 with three kinds of cation sites is reported.The influence of temperature,Eu2+ concentra-tion and excitation conditions on fluorescent properties of Eu2+ are studied at 77 and 298 K.Thecoordination number of Eu2+ at different sites is obtained.The green and red emission bands arise fromEu2+ ions locating on eight- and six- coordinated inequivalent sites respectively.