Synthesis and Thermal Properties of Three Energetic Ion Salts of 3,6-Bis[(1H-1,2,3,4-tetrazol-5-yl)-amino]-1,2,4,5-tetrazine

Three energetic ion salts of 3,6-bis[(1H-1,2,3,4-tetrazol-5-yl)-amino]-1,2,4,5-tetrazine(BTATz), namely, methylamine salt(compound 1), ethylenediamine salt(compound 2), and diethylamine salt(compound 3), were synthesized and characterized by elemental analysis, Fourier transform infrared spectrometry, NMR spectroscopy, and ^13C NMR spectroscopy. The crystal structure of compound 1 was determined by single-crystal X-ray crystallography, and structural analysis revealed that it belonged to the monoclinic system with P21/c space group. In addition, the thermal behavior of the three compounds was studied by differential scanning calorimetry and thermogravimetry techniques. The thermal decomposition peak temperatures of the compounds were 574.89, 545.60, and 606.72 K, indicating that the three ion salts exhibited good thermal stability. Tlie kinetic mechanism equations of the main decomposition process and the entropy of activation(△S^≠), enthalpy of activation(△H^≠), and Gibbs free energy of activation(△G^≠) of the three compounds were also obtained. Moreover, the thermal safety of the compounds was evaluated by the values of the self^accelerated decomposition temperature(Tsadt)5 thermal ignition temperature(TTIT), and critical temperature of thermal explosion(7b). The results showed that all the compounds demonstrated good thermal safety, and the thermal safety of compound 3 was better than that of the others.     

Thermal Kinetics and Decomposition Mechanism of Methylphenylphosphinic Acid and Diphenylphosphinic Acid

Thermal degradation and degradation kinetics of methylphenylphosphinic acid（MPPA） and diphenyl- phosphinic acid（DPPA） were investigated via thermogravimetric analysis（TGA） technique under non-isothermal conditions. The activation energies of the decomposition process for the two compounds were calculated through the Friedman and Kissinger-Akahira-Sunose（KAS） methods. The thermal decomposition mechanism was investigated by the Criado method based on a set of TGA data obtained at different heating rates. It was shown that the activation energies calculated from the decomposition reaction by different methods were consistent with each other. The results show that the probable model for the degradation of MPPA and DPPA agreed with the two-dimensional（D2） and three-dimensional（D4） diffusion models, respectively. Moreover, the thermodynamic functions（△H, △S, △G） of the two decomnosition reactions were also calculated.     

The High-spin↔Low-spin Equilibrium of Iron(Ⅱ) Complexes with Schiff Base Ligand:Optical,Magnetic and Spectroscopic Properties

Spin transition compounds are of great interest because of their potential application in molecular based electronic devices such as optical memoty and switch, display and data record^[1]. The occurrence of iron(Ⅱ) spin crossover systems depends on the ligand field strength. Iron(Ⅱ) spin crossover compounds mainly have sixfold nitrogen coordination and the range of lODq is very narrow:10Dq^HS≈11500-12500 cm^-1 and 10Dq^LS≈19000-21000 cm^-1[2]. The sensitivity of the spin state to small perturbations suggests that new coordination complexes exhibiting spin transition phenomena could be designed through a fine tuning of the ligands surrounding the metal. The derivatives of 1,2,4-triazole have been found to generate an intermediate ligand field force and the iron(Ⅱ) compounds containing such ligands which yielded spin-crossover materials exhibiting cooperative behavior have been reported recently^[3]. In this paper we present two new iron(Ⅱ) compounds FeL₃(ClO₄)₂·2H₂O (1) and FeL₃(BF₄)₂·3H₂O (2),where L is the Schiff base ligand derived from 4-amino-l,2,4-triazole and benzaldehyde. The compounds appear as white (HS) powders at room temperature and the color changes to pink (LS) upon decreasing the temperature to liquid nitrogen. 1 and 2 are investigated by the optical setup (520 nm, 293-77 K), ⁵⁷Fe Mössbauer Spectroscopy (293-77 K) and magnetic susceptibility (293-4 K). The HS→LS and LS→HS transitions were observed at Tc↓=135 K (1) and 169 K (2), and Tc↑=150 K (1) and 180 K (2), respectively. The thermal hysteresis is found to be 15 K and 11 K for 1 and 2. The area fractions are calculated to be 57% for 1 and 43% for 2. Variable temperature magnetic susceptibility data were fitted to magnetic susceptibility equations derived from domain model, two level Ising-type model and regular solution model. The calculated variations of enthalpy and entropy of the compounds fall within the limits ΔH≈8.1-10.9 kJ·mol^-1 and ΔS≈47-61 J·K^-1·mol^-1 found for mononuclear iron(Ⅱ) spin transition compounds from calorimetric measurements. The cooperativity parameter y determines the occurrence of hysteresis.     

F-(H2O)n(n=1～4)体系的结构、偶极矩、极化率和一阶超极化率的从头计算

用MP2方法得到F^-(H₂O)_n(n=1～4)体系的优化几何结构.依据优化结构计算偶极矩μ₀、极化率α₀、各向异性极化率Δα和一阶超极化率β₀,研究了基组效应.讨论了溶剂水分子数、溶剂水分子排布及溶剂层数变化诸因素对体系超极化率等性质的影响.     

Synthesis,crystal structure and thermal behavior of 4-amino-3,5-dinitropyrazole copper salt

A novel energetic combustion catalyst, 4-amino-3,S-dinitropyrazole copper salt （[Cu（adnp）2（H2O）2]）, was synthesized in a yield of 93.6% for the first time. The single crystal of [Cu（adnp）2（H2O）2] was determined by single crystal X-ray diffraction. It crystallizes in a triclinic system, space group p^-1 with crystal parameters a = 5.541（3） A, b = 7.926（4） A, c = 10.231（5） A,β = 101.372（8）°, V = 398.3（3） A3, Z = 1, μ = 1.467 mm^-1, F（0 0 0） = 243, and Dc = 2.000 g cm^-3. The thermal behavior and non-isothermal decomposition reaction kinetics of [Cu（adnp）2（H2O）2] were studied by means of different heating rate differential scanning calorimetry （DSC）. The kinetic equation of major exothermic decomposition reaction for [Cu（adnp）2（H2O）2] was obtained. The entropy of activation （△S≠）, enthalpy of activation （△H≠）, free energy of activation （△G≠）, the self-accelerating decomposition temperature （TSADT） and the critical temperature of thermal explosion （Tb） are 59.42 j mol^-1 K^-1, 169.5 kJ mol^-1, 1141.26 kJ mol ^-1 457.3 K and 468.1 K, respectively.     

Multi-component Hydrogen-bonding Organic Salts Formed from 1-Methylpiperazine with Aromatic Carboxylic Acids: Synthons Cooperation and Crystal Structures

1-Methylpiperazine was employed to crystallize with 2,4-dihydroxybenzoic acid and 1,8-naphthalene acid, affording two multi-component hydrogen-bonding salts [(C₅H₁₄N₂)²⁺·(C₇H₅O₄)_2-·H₂O](1) and [(C₅H₁₄N₂)²⁺(C₁₂H₆O₄)²ˉ·2H₂O](2). These two forms of salts are both monoclinic systems with space group P2₁/c(14). The lattice parameters of salts 1 and 2 are a=1.32666(10) nm, b=0.90527(7) nm, c=1.67107(13) nm, β=103.125(1)° and a=1.4950(2) nm, b=0.75242(15) nm, c=1.6563(3) nm, β=92.834(2)°, respectively. Expected classical hydrogen bonds N―H…O and O―H…O appear in the chargetransfer salts, and asymmetric units of these two forms both contain water molecules which play a significant role in building novel supramolecular architectures. Robust hydrogen-bond interactions between 1-methylpiperazine and aromatic acid provide sufficient driving force to direct the two crystals to three-dimensional structures. Weak interactions C―H…O emerging in salts 1 and 2 further enhance their crystal structures. As a consequence, hydrogen-bonding interactions in these compounds afford diverse 3D net supramolecular architectures. Thermal stability of these compounds was investigated by thermogravimetric analysis(TGA).     

微量热法研究漆酶和3,4,5-三羟基苯甲酸的反应

用LKB－2107型微量热系统,在不同的温度(pH＝7.4)条件下,测定了3,4,5－三羟基苯甲酸与漆酶反应的摩尔反应烙、米氏常数、反应速率常数、漆酶的活性并计算了结合能、活化自由能、活化能和活化烟等.在此基础上,应用过渡态理论,从能量变化的角度,对其催化过程进行了分析.由活化摘(△S_≠^T＜0)得出酶－底物过渡态的结构较酶－底物复合物更为有序的结论.     

Synthesis and in vitro Evaluation of Manganese（Ⅱ）-porphyrin Modified with Chitosan Oligosaccharides as Potential MRI Contrast Agents

Mn-TCPP-CSn（n=6,1 1,20） as a type of potential magnetic resonance imaging（MRI） contrast agents were synthesized via manganese（Ⅱ） meso-tetra（4-carboxyphenyl） porphyrin（Mn-TCPP） modified with chitosan oligosaccharides（CSn）.Experimental data of infared（IR）,UV-Vis,MS,inductively coupled plasma-atomic emission spectrometer（ICP-AES） and size exclusion chromatography evidenced the formation of Mn-TCPP-CSn-The stability results show that Mn-TCPP-CSn in aqueous solution was stable enough to prevent Mn（Ⅱ） ions from leaking.The magnetic properties in vitro indicate that Mn-TCPP-CS20 possesses higher longitudinal relaxivity（r1=10.38 L·mmol^-1·s^-1） in aqueous solution than unmodified porphyrin Mn-TCPPNa4[manganese（Ⅱ） meso-tetra（4-carboxyphenyl） porphyrin,tetrasodium salt]（r1=5.10 L·mmol^-1·s^-1） and the commercial contrast agent Gd-DTPA（r1=4.05 L·mmol^-1·s^-1）.The preliminary T1-weighted flash image studies in vitro show that the contrast and the imaging signal of Mn-TCPP-CSn were superior to those of Mn-TCPPNa4 and Gd-DTPA under the same conditions.The 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide（MTT） assay shows that Mn-TCPP-CSn has a good biocompatibility.In addition,the thermodynamical parameters（ΔH〈0,ΔS〈0,ΔG〈0） of Mn-TCPP-CSn bound to bovine serum albumin（BSA） show that Mn-TCPP-CSn could bind to BSA spontaneously,where the binding complex was stabilized mainly by van der Waals interactions and hydrogen bonds.These results suggest that Mn-TCPP-CSn have the advantage of becoming a potential MRI contrast agent.     

反气相色谱测定非对称双阳离子型离子液体的溶解度参数

在343.15~363.15 K下采用反气相色谱法对实验室合成的3种非对称双阳离子型离子液体[PyC₅Pi]NTf₂]₂、[MpC₅Pi]NTf₂]₂和[PyC₆Pi]NTf₂]₂的溶解度参数进行了测定。以正辛烷、正癸烷、正十二烷、正十四烷和正十六烷作为探针溶剂,计算了在不同温度下探针溶剂在3种离子液体中的特性保留体积(V_g⁰)、摩尔吸收焓(ΔH₁^S)、无限稀释摩尔混合焓(ΔH_l^∞)、摩尔蒸发焓(ΔH_v)、无限稀释活度系数(Ω₁^∞)以及探针溶剂与3种离子液体的Flory-HuggirIs相互作用参数(χ₁₂^∞),得到了室温下3种离子液体的溶解度参数(δ₂)为28.52~32.66 (J·cm^-3)^1/2。分子结构中含有4-甲基吗啉比含有吡啶时溶解度参数更大。随着两个阳离子间连接基碳数的增加,溶解度参数增大。这一结果对研究离子液体的溶液性质和应用有指导作用。     

Ca3Al2Ge3O12:Cr3+的光谱性质及晶场参数计算

为了解Cr3+离子在钙铝锗酸盐Ca₃Al₂Ge₃O₁₂:石榴石中的光谱性质, 合成了Ca₃Al₂Ge₃O₁₂:Cr³⁺多晶材料；测量了其X射线衍射图, 漫反射光谱, 激发、发射光谱等；分析了Cr3+离子在钙铝锗酸盐中的发光特性；计算了其晶场强度(Dq/B), Stokes位移(ΔEs)及黄昆-里斯因子(S)等. 在450 nm激发下, Ca₃Al₂Ge₃O₁₂:Cr³⁺室温发射光谱主要由三个宽带及附加其上的弱R线构成, 分别对应于Cr3+离子的4T1、 4T2、2T2到 4A2 能级跃迁. 低温时R线变得强而锐. 通过计算, Dq/B=2.43, ΔEs=1884 cm-1, S=5.21. 表明在Ca₃Al₂Ge₃O₁₂中Cr³⁺离子处于较弱的晶场强度, 电子-声子耦合较强, 为发展可调谐激光材料提供重要线索.     

手性赖氨酸基Gemini表面活性剂的表面性能

用表面张力法、电导法和稳态荧光法研究了手性Gemini表面活性剂[C₁₂-m-C₁₂] Na₂（m=2,4,6）和[C₁₂-T-C₁₂] Na₂的表面性能及临界胶束聚集数,并计算胶束形成的热力学参数,用圆二色谱法考察了[C₁₂-2-C₁₂] Na₂在不同浓度下的立体构型. 结果表明,手性Gemini表面活性剂的临界胶束浓度（cmc）和临界表面张力γ_cmc随着连接基链长增加或刚性增强而增大;ΔG_m⁰和ΔH_m⁰为负值,|ΔH_m⁰|比|-TΔS_m⁰|小很多,说明胶束化过程为熵驱动的自发放热过程;随着连接基链长增加或刚性增强,ΔG_m⁰和ΔH_m⁰逐渐增大,ΔS_m⁰和临界胶束聚集数逐渐减小,表明其胶束化能力随之降低;当浓度大于cmc时,手性Gemini表面活性剂可形成手性超分子聚集体.     

Preparation and Standard Formation Enthalpy of 2－Amino－4,6－dimethylpyrimidine and Its Related Complexes of Copper

IntroductionThe pyrimidine and its derivatives are knownto possess extraordinary biological properties thatare generally distinguished qualitatively by havingbeen used as pesticide,herbicide,bactericide,andmedicine intermediates[1] .A survey of these appli-cations and a number of the related variations thathave been developed recently,such as the extraor-dinary effective herbicide of sulfonyl sulfourea,re-veals that the biological properties are just becauseof the wide existence of pyrimidine …     

Synthesis and Thermal Behavior of 1,8-Dihydroxy- 4,5-dinitroanthraquinone Manganese Salt

A novel energetic combustion catalyst, 1,8-dihydroxy-4,5-dinitroanthraquinone manganese salt （DHDNEMn）, was synthesized by virtue of the metathesis reaction in a yield of 91%, and its structure was characterized by IR, element analysis and differential scanning calorimetry（DSC）. The thermal decomposition reaction kinetics was studied by means of different heating rate DSC. The results show that the apparent activation energy and pre-exponential factor of the exothermic decomposition reaction of DHDNEMn obtained by Kissinger＇s method are 162.3 kJ/mol and 1011.8 s^-1, respectively. The kinetic equation of major exothermic decomposition reaction of DHDNEMn is dα/dT= 10^118/β 2/5（1-α）[-ln（1-α）[-ln（1-α）]^3/5 exp（-1.623×10^5/RT）. The entropy of activation（△S^≠）, enthalpy of activation（△H^≠） and free energy of activation（A△G^≠） of the first thermal decomposition are -24.49 J·mol^-1·K^-1, 185.20 kJ/mol and 199.29 kJ/mol（T=575.5 K）, respectively. The self-accelerating decomposition temperature（TSADT） and critical temperature of thermal explosion（Tb） are 562.9 and 580.0 K, respectively. The above-mentioned information on the thermal behavior is quite useful for analyzing and evaluating the stability and thermal safety of DHDNEMn.     

一种阴离子型三维金属有机框架材料Cu(BDC-NH_2)(4,4'-Bipy)_(0.5)(BDC=对苯二甲酸根,Bipy=联吡啶)的制备及其对甲基紫的吸附性能

以2-氨基对苯二甲酸、4,4'-联吡啶配体和硝酸铜为原料,在溶剂热的条件下,合成了一种的阴离子型三维金属有机框架(MOF)材料Cu(BDC-NH_2)(4,4'-Bipy)_(0.5)(BDC=对苯二甲酸根,Bipy=联吡啶)。通过IR、XRD、SEM、TG、N_2吸附法测比表面积等技术手段表征材料的结构和性能。研究了Cu(BDC-NH_2)(4,4'-Bipy)_(0.5)材料对甲基紫的吸附性能,探讨了甲基紫溶液的初始p H值和初始浓度以及不同吸附温度对吸附量的影响。结果表明,等温吸附模型符合Langmuir等温吸附模型,动力学符合拟二级动力学。热力学参数ΔG0、ΔΗ0和ΔS0,表明Cu(BDC-NH_2)(4,4'-Bipy)_(0.5)对甲基紫的吸附是自发和放热的,在溶液p H=9,温度为20℃条件下,Cu(BDC-NH_2)(4,4'-Bipy)_(0.5)对甲基紫的吸附量为60.09 mg/g,说明Cu(BDC)(4,4'-Bipy)_(0.5)材料可以通过氨基改性,提高其对染料的吸附能力。     

Hydrothermal Synthesis,Structure and Property of Transition Metal(Mn,Zn, Cd or Pb) Coordination Frameworks Using Quinoline-8-oxy-acetate Acid and Dicarboxylic Acid as Ligands

Five transition metal coordination compounds, [Mn₂(8-qoac)₂(bdc)(H₂O)₄](1)(8-qoacH=quinoline-8-oxy- acetate acid, H₂bdc=benzene-1,4-dicarboxylic acid), [Zn₄(8-qoac)₄(bdc)₂]_n(2), {[Cd₂(8-qoac)₂(Hip)₂(H₂O)₂]· (H₂O)₄}_n(3)(H₂ip=benzene-1,3-dicarboxylic acid), [Pb₃(8-qoac)₂(bdc)_1.5(H₂O)Cl]_n(4) and [Zn₂(8-qoac)(8-ql)(bdc)]_n (5)(8-Hql=8-hydroxyquinoline), were synthesized by hydrothermal syntheses of metal salts with benzenedicarboxy- lic acid and 8-qoacH. Compound 1 possesses a discrete dimer bridged by bdc^2- ligand. Compound 2 presents a 2D layer network constructed from bdc^2- linkers and 1D infinite ribbons, in which Zn(II) centers are bridged by 8-qoac^- with a tetradentate binding mode. Compound 3 displays a 1D zigzag chain, with adjacent chains further connected via extensive O-H···O hydrogen bonds to generate a 3D supramolecular structure. Compound 4 shows a 3D framework containing trinuclear lead secondary building units and bdc^2- linkers, in which a new coordination mode of 8-qoac^- ligand is observed. In compound 5, Zn(II) ions are simultaneously bridged by 8-qoac^-, 8-ql^- and bdc^2- ligands to form tetranuclear zinc units, which are further interlinked by bdc^2- linkers to yield a 2D wave-like layer. Based on intraligand(IL)(π-π^*) fluorescent emission, compounds 1―5 possess strong purple fluorescent emissions. In addition, the thermal stabilities of compounds 1―5 were studied.     

Al代位合金化对D88-Ti5Si3力学性能与电子结构影响的第一性原理研究

采用基于密度泛函理论(DFT)的第一性原理赝势平面波方法, 计算了不同数量的Al 原子代位六方D8₈结构的Ti₅Si₃晶体中的Si 原子后的形成能(ΔH_f)、结合能(ΔE_coh)、体模量(B)、剪切模量(G)、泊松比(ν)、Cauchy 压力参数(C₁₂―C₆₆,C₁₃―C₄₄)、金属性(f_m)和派-纳力(τ_P-N)等参数, 表征了Al 合金化对D8₈-Ti₅Si₃的结构稳定性和力学性质的影响. 结合态密度、差分电荷密度图和Mulliken 布居等电子结构分析, 揭示了Al 原子的添加量对D8₈-Ti₅Si₃的韧/脆性变化的影响机制. 研究表明, D8₈-Ti₅Si₃晶体中强的Ti^6g―Si^6g方向共价键是导致其室温脆性的主要原因. 当1 个和2 个Al 原子占据D8₈-Ti₅Si₃晶体中Si^6g位置时, 形成了键强较弱的Al^6g―Si^6g键、Ti^6g―Al^6g键和Ti4d―Al^6g键, 同时降低了D8₈-Ti₅Si₃中Ti^6g―Si^6g键的强度和数量, 从而提高了D8₈-Ti₅Si₃的韧性. 当D8₈-Ti₅Si₃晶体中Si^6g位置被3个Al 原子所占时, Al^6g―Si^6g键消失, 而Ti^6g―Si^6g键的强度增加, 导致Ti₅(Si_1-xAl_x)₃的脆性增加.     

沉淀基离子选择电极对干扰离子的动力学响应研究

用活度阶梯法研究了AgI,AgBr,CuS,PbS和CdS电极对干扰离子的动力学响应.溶液中含一定浓度主要离子时上述电极对某些干扰离子响应非单一突跃型瞬时信号;溶液中不含主要离子时,除了AgBr电极响应Cl^-外,其它都响应单一瞬时信号.离子交换产物的溶解度越小,离子的水合焓差越小,瞬时信号峰高度越大.离子水合焓差对瞬时信号峰高度的影响说明,试液高速喷向电极表面时由于扩散层厚度很薄,电极对干扰离子响应瞬时信号的峰电位不决定于离子扩散速度,而决定于离子交换速度.除CuS电极外,根据其它电极非单一突跃型瞬时信号所测定的平衡电位选择性系数K_xy^e与相应化合物溶度积比值是一致的.     

三岔共轭体系中的结构效应(Ⅱ)——分子轨道能量与键级

本文计算了双向型、合流型、分流型三岔共轭多烯链物的分子轨道能级,能级差量。它们的同系递变与相应线型共轭体系一样,也遵守同系线性规律。但它们的同系直线在截距和斜率上都表现有一定的差异,这些差异定量地表明了三岔共轭体系中一根分岔只起代基的作用。这样,由分子基态中轨道能级的同系直线的差异,即可找出作为代基的分岔基团的代基当量。 中心碳原子周围的p_2-3与p_2-N键级的同系直线和用能级因子考查三岔共轭体系的分子轨道能级和键级,所得结果也说明三岔共轭体系的侧链为代基。     

A high-efficient amperometric hydrazine sensor based on novel electrospun CoFe2O4 spinel nanofibers

HeterojunctionFe_2O_3 nanoparticles(NPs), NiFe_2O_4 nanofibers(NFs), and CoFe_2O_4 NFs were synthesized by electrospinning and the subsequent thermal treatment processes. Characterization results indeed display the three-dimensional net-like textural structures of these as-electrospun spinel-type MFe_2O_4 NFs. The MFe_2O_4 NFs-based film configurations possess abundant micro/meso/macropores on their surface. These structures could afford more accessible transport channels for effective reduction of the mass transport resistance and improvement of the density of exposed catalytic active sites. All these advantages are responsible for the enhanced electro-catalytic performance of these MFe_2O_4 NFs in hydrazine oxidation. When used for hydrazine detection, CoFe_2O_4 NFs show the best catalytic efficiency.For example, the CoFe_2O_4 NFs possess a large sensitivity of 1327 mA cmà2(mmol Là1[à1in the linear range of 0.01 to 0.1 mmol Là1and 503 mA cmà2(mmol Là1)à1in the linear range of 0.1 to 11 mmol Là1, a response time of shorter than 3 s, good reproducibility and remarkable long-term stability. The superior catalytic efficiency, excellent stability, low cost, and ease of fabrication render CoFe_2O_4 NFs very promising materials in developing an electrochemical device that directly detects hydrazine.     

Voltammetric Studies on Heteropoly Phosphotungstovanadate Anions Across the Liquid／Liquid Interface

Electrochemical transfer behavior of V^vW11--V3^vW9 heteropoly anions on the water/nitrobenzene interface was investigated by means of cyclic voltammetry. The effect of the solution acidity on the transfer behavior and the stable pH range for the heteropoly anions were studied. The stability of mixed tungstovanadate decreases with increasing the number of vanadium atoms. The main transfer species within the potential window have the negative charges of 4 and the transfer process is diffusion-controlled. The apparent transfer potential Δo%wΨ^0 and the free energy ΔGcr^0 w→o for the heteropoly anions can be obtained from the experimental data. For the different anions, the Δo%wΨ1/2pH relationship can be expressed as: Δo%wΨ1/2=constant-53pH.