Equilibrium constants of nitration of alcohols and thermal stability of their nitrates

The data on equilibrium constants of the nitration of polyhydric alcohols and cellulose were examined and generalized. Changes in values of the equilibrium constants and Gibbs's energy of nitration related to the position of the nitrated hydroxyl group in the molecule and the existence of the adjacent hydroxyl and nitrate groups were established. An empirical method for calculating rates of thermal decomposition of different nitrate groups using experimental equilibrium constants of nitration was suggested. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1802–1804, October, 1997.     

Femtogram level quantitative determination of nitroglycerin and metabolites in human plasma by GC-MS negative ion chemical ionization,single ion monitoring

Recent developments in the use of negative ion detection in GC-MS have indicated the potential for highly sensitive analyses for certain compounds. This paper describes the application of the techniques to the assay of Nitroglycerin and its metabolites yielding sensitivity to two femtograms. Because of the low levels of nitroglycerin in biological media such sensitivity is highly desirable if not essential for meaningful measurements. In addition to sensitivity the method is shown to yield extremely good selectivity contributing further to the credibility of quantitative results.     

稀土硝酸盐与L－精氨酸固体配合物的合成与表征

报道了合成的九种稀土硝酸盐与精氨酸的配合物，经化学分析和热重分析确定了其组成为ＲＥ（ＮＯ３）３（Ａｒｇ）２·４Ｈ２Ｏ（ＲＥ＝Ｌａ，Ｎｄ，Ｓｍ，Ｅｕ，Ｇｄ，Ｔｂ，Ｄｙ，Ｔｍ，Ｙ）．测定了配合物的红外光谱，并推测配体是通过羧基进行配位的     

Thermodynamic evaluation and optimization of the (NaNO3 + KNO3 + Na2SO4 + K2SO4) system

A complete critical evaluation of all available phase diagram and thermodynamic data has been performed for all condensed phases of the (NaNO₃ + KNO₃ + Na₂SO₄ + K₂SO₄) ternary reciprocal system, and optimised model parameters have been found. The model parameters obtained for the four binary common-ion subsystems (i.e. (NaNO₃ + Na₂SO₄), (KNO₃ + K₂SO₄), (NaNO₃ + KNO₃) and (Na₂SO₄ + K₂SO₄)) are used to predict thermodynamic properties and phase equilibria for the entire system. The Modified Quasichemical Model in the Quadruplet Approximation for short-range ordering was used for the molten salt phase, and the Compound Energy Formalism was used for the various solid solutions.     

Crystal structure of 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo [8.8.8]hexacosane nitrate-hydrogen nitrate perchlorate semihydrate

An adduct of 2.2.2-cryptand with nitric and perchloric acids of the [H₂(Crypt-222)· 0.52H₂O]²⁺·ClO ₄ ^? ·NO ₃ ^? ·HNO₃ composition (I) is prepared and characterized by single crystal X-ray diffraction. The triclinic structure of I (space group \(P\overline 1 \), a = 10.176 Å, b = 11.272 Å, c = 12.870 Å, α = 78.61°, β = 76.62°, γ = 79.88°, Z = 2) is solved by a direct method and refined in the full-matrix anisotropic approximation to R = 0.062 for all 3642 measured independent reflections (CAD-4 automated diffractometer, λMoK _α). The structure of I contains a dication of 2.2.2-cryptand in the endo-endo conformation, two hydrogen atoms at the protonated N atoms are directed inside the cavity which also includes a water molecule with a site occupation factor of 0.52. Tetrahedral ClO ₄ ^? anion in I is disordered. In I, the H atom of the NO ₃ ^? ·HNO₃ dimer is split over two close positions with occupation factors of 0.33 and 0.67; this dimer is joined by a very strong single disordered hydrogen bond N-O-H?O = N between the molecule of nitric acid and its anion.     

粘土矿物材料用于水中硝酸盐去除的研究进展

硝酸盐污染威胁着环境安全和人体健康,储量高、易获取、低价高效的粘土矿物材料作为硝酸盐脱除剂极具潜力。首先从硝酸盐的特性和来源出发,介绍了用于水中硝酸盐去除的天然粘土矿物,包括高岭土、凹凸棒土、伊利石、海泡石和膨润土,发现它们普遍存在着离子交换容量较低、选择吸附性不高的问题。接着归纳了目前常用的改性方法和复合方法：两种方法均能有效提升粘土矿物材料对硝酸盐的脱除能力,改性技术能够改良其表面性质,调整表面官能团的种类和数量,其中表面活性剂改性所取得的成效更优;复合技术能够拓宽其功能性,获取更多的操作性和性能提升,其中同双金属离子或壳聚糖复合是更好的办法。然后分析了粘土矿物材料的毒性,总结出其具有制备低毒性和高生物相容性复合材料的潜力,但需要对改性剂的选择和使用浓度进行严格的控制。最后,展望了未来粘土矿物材料在硝酸盐去除方面的研究重点和发展方向,为开发用于硝酸盐去除的新型粘土矿物材料提供理论支持和参考。     

Field Measurement of NO2 and RNO2 by Two-Channel Thermal Dissociation Cavity Ring Down Spectrometer

A two-channel thermal dissociation cavity ring down spectroscopy (CRDS) instrument has been built for in situ, real-time measurement of NO₂ and total RNO₂ (peroxy nitrates and alkyl nitrates) in ambient air, with a NO₂ detection limit of 0.10 ppbv at 1 s. A 6-day long measurement was conducted at urban site of Hefei by using the CRDS instrument with a time resolution of 3 s. A commercial molybdenum converted chemiluminescence (Mo-CL) instrument was also used for comparison. The average RNO₂ concentration in the 6 days was measured to be 1.94 ppbv. The Mo-CL instrument overestimated the NO₂ concentration by a bias of +1.69 ppbv in average, for the reason that it cannot distinguish RNO₂ from NO₂. The relative bias could be over 100% during the afternoon hours when NO₂ was low but RNO₂ was high.     

硝酸稀土组氨酸配合物的拉曼光谱

研究了组成为ＲＥ（Ｈｉｓ）（ＮＯ３）３·Ｈ２Ｏ（ＲＥ＝Ｌａ～Ｎｄ,Ｓｍ～Ｌｕ,Ｙ;Ｈｉｓ＝Ｌ～ａ－ｈｉｓｔｉｄｉｎｅ）固态配合物的拉曼光谱。结果表明,配合物中ＲＥ＾３＋与羧基氧原子配位,氨基和味唑环均未参与配位,ＮＯ３＾－为双齿配位。配合物羧基振动峰的ΔυＣＯＯ＾ａｓ－ｓ－与镧系离子的原子序数作图服从Ｏｄｄｏ－Ｈａｒｋｉｎｓ规律。     

Mechanism of Thermal Decomposition of d-metals Nitrates Hydrates

A series of six nitrates(V) hydrates of 4d-metals as well as mercury and cadmium thermal decomposition was examined by DTA, TG and EGA techniques. It was found that thermal decomposition of d-metals nitrate(V) hydrates proceeds in three stages: partial dehydration, oxo-nitrates and hydroxide nitrates formation and metal oxides formation. General chemical equations for all decomposition stages were proposed. It was found that dehydration of hydrated salts is accompanied by partial decomposition of nitrate(V) groups. This revised version was published online in August 2006 with corrections to the Cover Date.