Double Nitrate Research Articles

Differential metabolic rearrangements in the roots and leaves of Cicer arietinum caused by single or double nitrate and/or phosphate deficiencies.

Nitrate (NO3 - ) and phosphate (Pi) deficiencies are the major constraints for chickpea productivity, significantly impacting global food security. However, excessive fertilization is expensive and can also lead to environmental pollution. Therefore, there is an urgent need to develop chickpea cultivars that are able to grow on soils deficient in both NO3 - and Pi. This study focused on the identification of key NO3 - and/or Pi starvation-responsive metabolic pathways in the leaves and roots of chickpea grown under single and double nutrient deficiencies of NO3 - and Pi, in comparison with nutrient-sufficient conditions. A global metabolite analysis revealed organ-specific differences in the metabolic adaptation to nutrient deficiencies. Moreover, we found stronger adaptive responses in the roots and leaves to any single than combined nutrient-deficient stresses. For example, chickpea enhanced the allocation of carbon among nitrogen-rich amino acids (AAs) and increased the production of organic acids in roots under NO3 - deficiency, whereas this adaptive response was not found under double nutrient deficiency. Nitrogen remobilization through the transport of AAs from leaves to roots was greater under NO3 - deficiency than double nutrient deficiency conditions. Glucose-6-phosphate and fructose-6-phosphate accumulated in the roots under single nutrient deficiencies, but not under double nutrient deficiency, and higher glycolytic pathway activities were observed in both roots and leaves under single nutrient deficiency than double nutrient deficiency. Hence, the simultaneous deficiency generated a unique profile of metabolic changes that could not be simply described as the result of the combined deficiencies of the two nutrients.

Parameters affecting mechanochemical nitration of aromatic precursors

Using MoO3 as catalyst and NaNO3 as nitronium source, aromatic precursors were nitrated in a planetary ball mill. Reaction times and nitrate/precursor molar ratios varied in the experiments. Nitration was observed with maximum yields approaching 80%. Product ratios of para to ortho isomers were consistently above 1, indicating reaction on the catalyst surface. Byproducts, including oxidation products and double nitration products, were observed. The product yield approached its theoretical maximum when the aromatic precursor was the limiting reactant; the yields remained well below their expected maxima when the limiting reactant was nitrate. Thus, the catalyst sites necessary to generate nitronium may be blocked by the excess of the aromatic precursor in such cases. Correlation of the reaction rates with characteristics of the precursors suggests the importance of both physical and chemical parameters. Factors affecting the reaction rate include the aromatic activation, basicity, enthalpy of vaporization, reaction enthalpies and viscosity.

Double Ligation and Topical Silver Nitrate

Double Ligation and Topical Silver Nitrate

Effects of increasing temperature and nitrate concentration on cell abundance, growth rate, biomass and free fatty acid of Tetraselmis sp

It is well known that marine microalgae have a high diversity and potency as natural food for aquaculture, a high bioactive compound, and source of biofuel. Tetraselmis sp. is one of the marine-green algae, which has a high lipid content. A completely randomized design was used in this experiment with four levels of temperature treatments (28°C, 30°C, 32°C, and 34°C) and three levels of nitrate treatments (0 gr/L, 0.2 gr/L and 0.4 gr/L) with length of culture was 21 days. The result of our study showed that the highest growth rate was found at 30°C with double nitrate concentration account for 0.20 cell/day. The highest biomass was found at 0.20 g/L nitrate treatment for 34°C temperature treatment account for 0.17 g/L, while the lowest dry weight was 0.08 g/L that was found at 0.0 g/L nitrate treatment for 28°C temperature treatment. The highest free fatty acid percentage was found at 30°C of temperature treatment at the 0.40 g/L of nitrate concentration treatment, account for 8.81 %. Statistically, results showed that increasing temperature affected significantly to biomass and free fatty acid while increasing nitrate was different significantly on growth rate, and biomass.

Structural, optical and electronic properties of K2Ba(NO3)4 crystal

Nitrate crystals reveal nonlinear optical properties and could be considered as converters of laser radiation in the short-wave region. The conditions for obtaining and basic properties of K2Ba(NO3)4 double nitrate crystals were investigated. Crystal growth was implemented by slow cooling in the temperature range of 72–49 °C and low rate evaporation. The structural analysis of K2Ba(NO3)4 formation on the basis of two mixed simple nitrate structures is discussed. The main groups of oscillations in K2Ba(NO3)4 crystal were revealed using Raman and IR spectroscopy, and the table of vibrations for this compound was compiled. The electronic structure of K2Ba(NO3)4 was elucidated in the present work from both experimental and theoretical viewpoints. In particular, X-ray photoelectron spectroscopy (XPS) was employed in the present work to measure binding energies of the atoms constituting the titled compound and its XPS valence-band spectrum for both pristine and Ar+ ion-bombarded surfaces. Further, total and partial densities of states of constituent atoms of K2Ba(NO3)4 have been calculated. The calculations reveal that the O 2p states dominate in the total valence-band region of K2Ba(NO3)4 except of its bottom, where K 3p and Ba 5p states are the principal contributors, while the bottom of the conduction band is composed mainly of the unoccupied O 2p states, with somewhat smaller contributions of the N 2p∗ states as well. With respect to the occupation of the valence band by the O 2p states, the present band-structure calculations are confirmed by comparison on a common energy scale of the XPS valence-band spectrum and the X-ray emission O Kα band for the K2Ba(NO3)4 crystal under study. Furthermore, the present calculations indicate that the K2Ba(NO3)4 compound is a direct-gap material.

Nitration of 5,11-dihydroindolo[3,2-b]carbazoles and synthetic applications of their nitro-substituted derivatives.

A new general approach to double nitration of 6,12-di(hetero)aryl-substituted and 6,12-unsubstituted 5,11-dialkyl-5,11-dihydroindolo[3,2-b]carbazoles by acetyl nitrate has been developed to obtain their 2,8-dinitro and 6,12-dinitro derivatives, respectively. A formation of mono-nitro derivatives (at C-2 or C-6) from the same indolo[3,2-b]carbazoles has also been observed in several cases. Reduction of 2-nitro and 2,8-dinitro derivatives with zinc powder and hydrochloric acid has afforded 2-amino- and 2,8-diamino-substituted indolo[3,2-b]carbazoles, while reduction of 6,12-dinitro derivatives under similar reaction conditions has been accompanied by denitrohydrogenation of the latter compounds into 6,12-unsubstituted indolo[3,2-b]carbazoles. Formylation of 6,12-dinitro derivatives has proved to occur only at C-2, while bromination of these compounds has taken place at both C-2 and C-8 of indolo[3,2-b]carbazole scaffold. Moreover, 6,12-dinitro-substituted indolo[3,2-b]carbazoles have been modified by the reactions with S- and N-nucleophiles. Notably, the treatment of 6,12-dinitro compounds with potassium thiolates has resulted in the displacement of both nitro groups, unlike potassium salts of indole or carbazole, which have caused substitution of only one nitro group.

Elevated CO2 improved the growth of a double nitrate reductase defective mutant of Arabidopsis thaliana: The importance of maintaining a high energy status

Impairments in leaf nitrogen (N) assimilation in C3 plants have been identified as processes conditioning photosynthesis under elevated [CO2], especially when N is supplied as nitrate. Leaf N status is usually improved under ammonium nutrition and elevated [CO2]. However, ammonium fertilization is usually accompanied by the appearance of oxidative stress symptoms, which constrains plant development. To understand how the limitations of direct fertilization with ammonium (growth reduction attributed to ammonium toxicity) can be overcome, the effects of elevated [CO2] (800ppm) exposure were studied in the Arabidopsis thaliana double nitrate reductase defective mutant, nia1-1/chl3-5 (which preferentially assimilates ammonium as its nitrogen source). Analysis of the physiology, metabolites and gene expression was carried out in roots and shoot organs. Our study clearly showed that elevated [CO2] improved the inhibited phenotype of the nitrate reductase double mutant. Both the photosynthetic rates and the leaf N content of the NR mutant under elevated CO2 were similar to wild type plants. The growth of the nitrate reductase mutant was linked to its ability to overcome ammonium-associated photoinhibition processes at 800ppm [CO2]. More specifically: (i) the capacity of NR mutants to equilibrate energy availability, as reflected by the electron transport equilibrium reached (photosynthesis, photorespiration and respiration), (ii) as well as by the upregulation of genes involved in stress tolerance were identified as the processes involved in the improved performance of NR mutants.

ChemInform Abstract: The Double Nitrate NaRb2(NO3)3, Intermediate Compound in the Binary Isobaric System NaNO3 + RbNO3; Thermal and Crystallographic Study.

AbstractCrystallographic and thermodynamic investigations of the NaNO3—RbNO3 phase diagram at ambient pressure reveal the existence of NaRb2(NO3)3 (451 K).

On the origin of the occasional spring nitrate peak in Greenland snow

Abstract. Ice core nitrate concentrations peak in the summer in both Greenland and Antarctica. Two nitrate concentration peaks in one annual layer have been observed some years in ice cores in Greenland from samples dating post-1900, with the additional nitrate peak occurring in the spring. The origin of the spring nitrate peak was hypothesized to be pollution transport from the mid-latitudes in the industrial era. We performed a case study on the origin of a spring nitrate peak in 2005 measured from a snowpit at Summit, Greenland, covering 3 years of snow accumulation. The effect of long-range transport of nitrate on this spring peak was excluded by using sulfate as a pollution tracer. The isotopic composition of nitrate (δ15N, δ18O and Δ17O) combined with photochemical calculations suggest that the occurrence of this spring peak is linked to a significantly weakened stratospheric ozone (O3) layer. The weakened O3 layer resulted in elevated UVB (ultraviolet-B) radiation on the snow surface, where the production of OH and NOx from the photolysis of their precursors was enhanced. Elevated NOx and OH concentrations resulted in enhanced nitrate production mainly through the NO2 + OH formation pathway, as indicated by decreases in δ18O and Δ17O of nitrate associated with the spring peak. We further examined the nitrate concentration record from a shallow ice core covering the period from 1772 to 2006 and found 19 years with double nitrate peaks after the 1950s. Out of these 19 years, 14 of the secondary nitrate peaks were accompanied by sulfate peaks, suggesting long-range transport of nitrate as their source. In the other 5 years, low springtime O3 column density was observed, suggesting enhanced local production of nitrate as their source. The results suggest that, in addition to direct transport of nitrate from polluted regions, enhanced local photochemistry can also lead to a spring nitrate peak. The enhanced local photochemistry is probably associated with the interannual variability of O3 column density in the Arctic, which leads to elevated surface UV radiation in some years. In this scenario, enhanced photochemistry caused increased local nitrate production under the condition of elevated local NOx abundance in the industrial era.

Highly double selective nitration of nitrostilbenes over zeolite.

A feasible zeolite-assisted ortho C-H nitration of nitrostilbenes has been developed for the first time, which can be used in situ. It uses acetyl nitrate as a mild, easily handled and commercially available nitrating reagent, leading to the synthesis of polynitrostilbenes with double selectivities and in good yields.

Application of Hydrazine Hydrate in the Synthesis of Octa(aminophenyl)silsesquioxane (OAPS) Poss

Octa(aminophenyl)silsesquioxane (OAPS) was prepared from octaphenyl silsesquioxane (OPS) in two steps, first nitration to obtain Octa(nitrophenyl)silsesquioxane (ONPS) then reduction by using the stable, inexpensive, and readily available hydrazine hydrate as the reducing agent in the presence of Iron(III)Chloride catalyst with a yield of around 87%. Hydrazine is a two-electron reducing agent whereas nitro group is a four-electron reduction process. The activated carbon serves as an adsorbent and electrical conductor enabling the reaction to occur by acting as a mediator between a two-electron reagent and a four-electron process. Adsorption provides a reducing potential and a supply of electrons from many hydrazines making possible the initial four-electron process even though each individual hydrazine is a two-electron donor. The product was characterized by FTIR and 1H NMR. The time period for preparation of ONPS from octaphenyl silsesquioxane was considerably shortened to avoid double nitration of the aromatic rings.

Electronic Spectra and Crystal-Field Analysis of Europium in Hexanitritolanthanate Systems

The luminescence spectra of Eu(3+) at a T(h) point-group site in the hexanitritolanthanate systems Cs(2)NaEu((14)NO(2))(6), Cs(2)NaEu((15)NO(2))(6), Rb(2)NaEu((14)NO(2))(6), Cs(2)LiEu((14)NO(2))(6), and Cs(2)NaY((14)NO(2))(6):Eu(3+) have been recorded between 19,500 and 10,500 cm(-1) at temperatures down to 3 K. The spectra comprise magnetic-dipole-allowed zero phonon lines, odd-parity metal-ligand vibrations, internal anion vibrations, and lattice modes, with some weak vibrational progressions based upon vibronic origins. With the aid of density functional theory calculations, the vibrational modes in the vibronic sidebands of transitions have been assigned. The two-center transitions involving NO(2)(-) stretching and scissoring modes are most prominent for the (5)D(0) → (7)F(2) hypersensitive transition. The onset of NO(2)(-) triplet absorption above 20,000 cm(-1) restricts the derived Eu(3+) energy-level data set to the (7)F(J) (J = 0-6) and (5)D(0,1) multiplets. A total of 21 levels have been included in crystal-field energy-level calculations of Eu(3+) in Cs(2)NaEu(NO(2))(6), using seven adjustable parameters, resulting in a mean deviation of ~20 cm(-1). The comparison of our results is made with Eu(3+) in the double nitrate salt. In both cases, the fourth-rank crystal field is comparatively weaker than that in europium hexahaloelpasolites.

Theoretical Studies of Electronic Paramagnetic Resonance g Factors for La2Mg3(NO3)12⋅24H2O

Lanthanum magnesium double nitrate (LMN) crystals can be used as material for adiabatic demagnetization, magnetic thermometers and a proton spin-polarized target in both physics and polarized neutron diffraction. In the past years, the double nitrates doped with transition metal or rare earth ions have been studied by experimental and theoretical methods. For instance, the electronic paramagnetic resonance (EPR) g factors of the Ce3+ ions in La2Mg3(NO3)12⋅24H2O crystal were measured decades ago. But until now, these useful experimental results have not been theoretically explained. In this work, The EPR g factors of the trigonal Ce3+ centers in La2Mg3(NO3)12⋅24H2O are theoretically studied from the perturbation formulae of the EPR parameters for a 4f1 ion under the trigonal symmetry crystal field. The used crystal parameters are obtained from the superposition model and the local structure of the studied crystal. The calculated results are reasonably constant to the observed values. The results are discussed.

Effect of metal powders on γ-ray-induced decomposition of 2KNO3·La(NO3)3·2H2O

It is a well-known fact that metals remain unaffected by electromagnetic radiation in general. However, they may be influenced to some extent by the formation of certain microstructural changes because of γ -radiation. The experimental data showed that γ -radiolysis of double nitrate was influenced by the presence of metal powders in the admixture. The decomposition of the double nitrate exhibits linear correlation with the first ionization potential of the metals (r=0.9787) at 25 mol%. However, at higher concentrations of 50 and 75 mol% metal powders, poor correlation is observed, especially for Sn, Fe and W, which all show variable oxidation states, unlike Al and Zn, which exhibit stable oxidation states of+3 and+2, respectively.

A novel and facile method for the synthesis of octa(aminophenyl)silsesquioxane and its nanocomposites with bismaleimide‐diamine resin

AbstractOcta(aminophenyl)silsesquioxane (OAPS) was prepared from octa(nitrophenyl)silsesquioxane (ONPS) by using the stable, inexpensive, and readily available hydrazine hydrate as the reducing agent with a yield of around 86%. The product was characterized by FTIR, GPC, 1H NMR, 29Si NMR, and XRD. It was found that the time period for preparation of ONPS from octaphenylsilsesquioxane could be considerably shortened, reaching the complete nitration and avoiding double nitration of the aromatic rings. The polyimides were prepared by the reaction of N,N′‐bismaleimido‐4,4′‐diphenylmethane with OAPS and 4,4′‐diamino‐diphenyl ether. The structure of resulting organic–inorganic hybrid nanocomposites was characterized by XRD and FTIR. The decomposition temperature and char yield of resulting materials increased with increasing OAPS loading. The DSC data showed that the glass transition temperature of nanocomposite was enhanced by 36°C with the content of OAPS around 15 wt %. As the feed amount of OAPS increased further, the decrease in Tg's could be observed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1004–1010, 2007

Synthesis and Characterization of Energetic 1,2‐Bis(Oxyamino)Ethane Salts

AbstractThe synthesis, characterization, theoretical calculations, and safety studies of energetic salts based on 1,2‐bis(oxyamino)ethane, (H2NOCH2CH2ONH2), were carried out. The salts were characterized by vibrational (infrared, Raman), multinuclear NMR studies (1H, 13C), differential scanning calorimetry (DSC), elemental analysis, and initial safety testing (impact and friction sensitivity). Single crystal X‐ray diffraction studies were carried out on the mono‐perchlorate and the double nitrate salts, revealing the expected structures.

Combustion Properties of Gas-Generating Pyrotechnics

This work focuses particularly on solid energetic materials designed to produce high-pressure gas for pressurizing or inflating devices. In coot gas generators sodium azide is often used. Unfortunately, this chemical exhibits drawbacks concerning toxicity and yield of gas. Another gas-generating agent is double base propellant, which has traditionally been used in the rocket-industry. However, it delivers toxic and reactive gases and its combustion temperature is high. In previous work a series of gas-generating materials have been proposed as potential alternatives fueled with double base propellant, azodicarbonamide, nitroguanidine, or guanidine nitrate and stoichiometricly oxidized with potassium nitrate or potassium perchlorate. The purpose of this paper is to examine and compare the burning characteristics of the previously proposed compositions. To carry out this characterization, methods typical for propellant technology are used. Ignition delay, time from ignition to maximum pressure, burning rate, and absolute vivacity have been investigated through closed vessel tests. Thanks to the use of a gaseous ignition mixture the form function of the tested grains is not deteriorated. This leads to fairly reproducible results for the burning rate and the absolute vivacity, despite possible discrepancies in the ignition delay. In most of the studied cases, the addition of an oxidizer tends to improve the ignition delay and the time from ignition to maximum pressure. In addition the burning rate and absolute vivacity increase significantly. The only exception is double base propellant, where the presence of an oxidizer causes relatively minor changes in its combustion properties.

ChemInform Abstract: A Novel Method for the Nitration of Deactivated Aromatic Compounds.

Novel nitration systems comprising nitric acid, trifluoroacetic anhydride and zeolite Hβ, with or without acetic anhydride, are described. The system having no acetic anhydride is more active and readily nitrates deactivated substrates such as nitrobenzene, benzonitrile, benzoic acid or 4-nitrotoluene to give predominantly the product substituted meta to the deactivating group.The system incorporating acetic anhydride is more moderate in activity, and nitrates moderately deactivated systems such as halogenobenzenes quantitatively within two hours at ice–salt bath temperature, and provides very high selectivity for the para-nitrated product. This system also nitrates 2-nitrotoluene to give high selectivity for 2,4-dinitrotoluene production. Furthermore, the system can be used for direct double nitration of toluene and gives a 92% yield of 2,4-dinitrotoluene with a 2,4-∶2,6-dinitrotoluene ratio of 25∶1. Even greater selectivity (96% yield and 70∶1 selectivity) can be achieved in the latter reaction by conducting the reaction in one flask but in two stages, with trifluoroacetic anhydride added only in the second stage. p

Raman and infrared spectroscopic investigation of the neutralisation of aluminium in the presence of monomeric orthosilicic acid

The tridecameric aluminium polymer [AlO 4Al 12(OH) 23(H 2O) 12] 7+-O-Si(OH) 3 was prepared by forced hydrolysis of Al 3+ up to an OH/Al molar ratio of 2.0 in the presence of monomeric orthosilicic acid with increasing Si/Al ratio up to 1.00. Crystalline material was obtained by slow evaporation. The Raman spectra are characterised by the similar bands as the Al 13 nitrate. The Fourier transform-IR spectrum of the Al 13 crystals without any SiO(OH) 3 added indicates that previous assignments of the bands between 450 and 800 cm −1 to the sulphate in the crystal structure of basic aluminium sulphate are not correct for the Al 13 in this study. These bands are more likely to correspond with deformation bands within the Al octahedra of the Al 13 complex. Upon increasing the Si/Al ratio, a part of the nitrate is replaced as evidenced by the decrease in intensity of one of each set of double nitrate bands in both the Raman and Fourier transform-IR spectra. The incorporation of SiO(OH) 3 in the crystal structure results in the formation of new Fourier transform-IR bands at 3740 cm −1 assigned to silanol groups, 1106 cm −1 assigned to Si–O stretching mode and a band at 724 cm −1 assigned to Si–O–Al deformation mode. The formation of the [AlO 4Al 12(OH) 23(H 2O) 12] 7+-O-Si(OH) 3 therefore is thought to proceed via the replacement of incorporated nitrate groups in the Al 13 structure instead of via the hydroxyl groups.

Study of the Denitrifying Enzymatic System of Comamonas sp. Strain SGLY2 Under Various Aeration Conditions with a Particular View on Nitrate and Nitrite Reductases

This paper studies the effect of oxygen on the denitrifying enzymatic system of Comamonas sp. It is shown that nitrate respiration can take place in the presence of oxygen. Indeed, even if a protein synthesis inhibitor is added in the medium, immediate nitrate consumption is observed in an aerobic culture inoculated with cells that have never been subjected to nitrate. Existence of a constitutive nitrate reductase could explain this phenomenon. Moreover the nitrate and nitrite reductases are active and synthesized under aerobic conditions. The different levels of inhibition of nitrate reductase activity by respiratory inhibitors and detergent, according to the aerobic and anaerobic cultures, might suggest the existence of a double nitrate reductase enzymatic system.