锂离子电池正极材料Li(1-2x)MgxMnPO4/C的合成与表征

采用溶胶凝胶法合成前驱体,再在空气气氛中分别于400℃、500℃和600℃下焙烧,得到锂离子电池正极材料(1-2x)MgxMnPO4/C(0≤x≤0.1);利用X射线衍射分析、环境扫描电镜分析、恒流充放电、阻抗测试等分析了产物的结构、形貌和电化学性能.结果表明,合成的(1-2x)MgxMnPO4/C颗粒呈球形,具有橄榄...     

La10(SiO4)6-x(GaO4)xO3-0.5x的合成及其导电性能

以溶胶-凝胶法合成前驱体, 在950 ℃时烧结制得La10(SiO4)6－x(GaO4)xO3－0.5x (x＝0, 0.5, 1.0, 1.5和2.0)陶瓷样品, 通过TG-DTA, XRD, IR和SEM表征, 所得产品为磷灰石相. 以电化学阻抗谱研究了其导电性能, 发现决定电导率大小的因素有两种, 一是间隙氧的数量, 二是晶胞的大小, 两种因素的综合作用, 使得La10(SiO4)5(GaO4)O2.5的电导率最大, 在700 ℃时其电导率达到4.66×10－2 S•cm－1. 离子迁移数和氧分压对电导率的研究表明, 其主要的电荷载体是O2－离子.     

钠快离子导体Na1+xZr2-yTiySixP3-xO12系统的研究Ⅲ

通过高温固相反应合成了Na_(1+x)Zr_(2-y)Ti_y,Si_xP_(3-x)O_(12)系统y=1,x=0-2.0的一系列合成物.其合成反应温度低于Zr-NASICON的合成温度.研究了系统的相变关系以及电导率、电导激活能与化学组成的关系.研究了系统合成物对水的稳定性.结果表明y=1.0,x=0.9的合成物的电导性能最好,对水的反应性也较小,其电导率在室温时为3.64×10~(-4)(Ω·cm~(-1)),在623K时为1.25×10~(-1)(Ω·cm)~(-1),其激活能为26.35kJ/molc(0.27cV)(473-673K).     

五,六硝酸根合稀土(Ⅲ)酸4-[2-(3-硝基-4-甲氧基苯基)乙烯基]-1-甲基吡啶配合物的合成及性质

合成了通式为(C~1~5H~1~5N~2O~3)~xRE(NO~3)~y(当RE=La～Gd时,x=3,y=6,RE=Tb～Lu,Y时,x=2,y=5)的一个系列十五种五,六硝酸根合稀土(Ⅲ)酸4-[2-(3- 硝基-4-甲氧基苯基)乙烯基]-1-甲基吡啶配合物.通过元素分析, 紫外光谱, 红外光谱,^1H核磁共振谱,热重-差热分析,摩尔电导和X 射线粉末衍射分析等对各配合物的结构和性质进行了表征,并对影响其组成变化的因素作了初步探讨     

五,六硝酸根合稀土(Ⅲ)酸4-[2-(3-硝基-4-甲氧基苯基)乙烯基]-1-甲基吡啶配合物的合成及性质

合成了通式为(C_(15)H_(15)N_2O_3)_xRE(NO_3)_y(当RE=La～Gd时,x=3,y=6;RE=Tb～Lu,Y时,x=2,y=5)的一个系列十五种五、六硝酸根合稀土(Ⅲ)酸4-[2-(3-硝基-4-甲氧基苯基)乙烯基]-1-甲基吡啶配合物.通过元素分析、紫外光谱、红外光谱、’H核磁共振谱、热重-差热分析、摩尔电导和X射线粉末衍射分析等对各配合物的结构和性质进行了表征.并对影响其组成变化的因素作了初步探讨.     

催化剂含水量对合成(4-乙酰氨基)-苯基膦酸二乙酯的影响

有机膦酸酯在医药、农业、科研等领域具有重要的价值,研究提高有机膦酸酯合成时的选择性和转化率,对实际生产提高产量、降低成本具有重要意义.本论文通过Arbuzov反应,以对溴乙酰苯胺和亚磷酸三乙酯为原料,利用无水氯化镍的路易斯酸性催化C-P交叉偶联反应,合成了(4-乙酰氨基)-苯基膦酸二乙酯,并通过1H核磁共振、13C核磁共振、红外光谱和熔点测试等手段对产物结构进行表征.在合成中我们发现,无水氯化镍会逐渐与空气中的水分子结合形成水合氯化镍(Ni Cl2·x H2O),而氯化镍的含水量会直接影响其路易斯酸性,并最终影响合成(4-乙酰氨基)-苯基膦酸二乙酯的转化率.本文中,我们研究了氯化镍含水量对合成(4-乙酰氨基)-苯基膦酸二乙酯的影响,并找出了最优反应条件.     

合成4-叔丁基-4′-甲氧基二苯甲酰甲烷的新方法

对叔丁基苯甲醛与对甲氧基苯乙酮在甲醇钠作用下缩合生成1-(4-甲氧基苯基)-3-(4-叔丁基苯基)-2-丙烯-1-酮(1,收率91%);1经溴加成,甲醇钠脱溴合成4-叔丁基4′-甲氧基二苯甲酰甲烷(收率89%),总收率81%,其结构经UV-Vis和1H NMR表征.     

4-溴吲哚衍生物的合成

以4-溴吲哚为原料,经3步反应合成了1-甲基4-溴吲哚乙醇(4,总收率46.9%);经5步反应合成了1-甲基4-溴吲哚乙胺(6,总收率41.3%).4和6的结构经1H NMR,13C NMR和IR表征.4和6分别是合成具重要生理活性的天然产物Communesin和Clavicipitic acid的重要中间体.     

(2R，3R)-和(2S，3S)-2-(4-羟基-3-甲氧基)-3-羟甲基-1，4-苯并二氧六环-6-醛的对映选择性合成

1,4-苯并二氧六环木脂素类天然产物多数具有增加胆碱乙酰化酶和抗肝毒等活性 ,其活性主要源于 1 ,4-苯并二氧六环官能团 [1] . 1 ,4-苯并二氧六环木脂素的消旋全合成已有报道 [2 ] ,但其不对称合成还是空白[3] .我们发展了一条对映选择性合成 1 ,4-苯并二氧六环木脂素的简捷有效的路线 .基于前面的工作 [4 ] ,我们发现 1 ,4-苯并二氧六环醛类衍生物是合成此类天然产物的关键中间体 ,选择 2 - (4-羟基- 3-甲氧基 ) - 3-羟甲基 - 1 ,4-苯并二氧六环 - 6-醛 (1 )作为目标分子 ,其合成路线如下 :Reagents and conditions:( ) Me OH,H2 SO4,9…     

新型特效钠离子吸附剂Li1+xLaxZr2-x(PO4)3的制备和性能研究

采用高温固相法合成了新型特效Na离子吸附剂Li1 xLaxZr2-x(PO4)3.对不同条件下合成的吸附剂进行了XRD结构分析以及SEM分析和IR分析,并对其吸附性能进行了测定.XRD结构分析表明,当x≤0.4时均能得到与LiZr2(PO4)3相同的晶体结构.SEM分析表明,合成的吸附剂分散性好,粒径范围在5～20μm之间.吸附性能测定结果表明,少量La的加入使Li1 xLaxZr2-x(PO4)3对Na离子产生了特效吸附作用,La离子掺杂是改善LiZr2(PO4)3吸附性能的一条有效途径,当x=0.4时,在pH值为10.0～11.0条件下,Li1 xLaxZr2-x(PO4)3的吸附容量达到48.3mg/g.     

Stabilization Studies on Divalent Five‐Membered Rings C4H4C,C4H4Si,C4H4Ge,C4H4Sn,and C4H4Pb

Energy differences, ΔX_S‐t (X = E, H and G) (ΔX_S‐t = X_(singlet)‐X_(triplet)) between singlet (s) and triplet (t) states are calculated at B3LYP/6‐311++G (3df,2p). The DFT calculations show that the triplet state of C₄H₄C is a ground state with planar conformer respect to its corresponding nonplanar singlet state. Both singlet and triplet states of C₄H₄M (M = Si, Ge, Sn and Pb) have a planar conformer with the singlet ground state. Four isodesmic reactions are presented for determining the stability energies, SE. NICS calculations are carried out for C₄H₄M to determine the aromatic character.     

NH4VO3在NH4H2PO4-H2O和(NH4)3PO4-H2O体系中的溶解度

采用等温溶解法测定了偏钒酸铵(NH₄VO₃)在NH₄H₂PO₄-H₂O和(NH₄)₃PO₄-H₂O体系中T = 298.15-328.15 K时的溶解度以及溶液的密度和pH值。结果表明, NH₄VO₃的溶解度随着(NH₄)₃PO₄或NH₄H₂PO₄溶液浓度的增大,先降低后升高,这是由于同离子效应、化学反应平衡及离子活度的共同作用。比较T = 298.15K时, NH₄VO₃分别在NH₄H₂PO₄-H₂O、(NH₄)₂HPO₄-H₂O和(NH₄)₃PO₄-H₂O体系中溶解度,发现在相同的磷酸盐浓度下, NH₄VO₃的溶解度在NH₄H₂PO₄-H₂O体系中最大,在(NH₄)₃PO₄-H₂O体系中居中,在(NH₄)₂HPO₄-H₂O体系中最小。进一步地,在T = 298.15 K和磷酸盐浓度C = 0.5 mol·kg^-1时,结合pH值和反应溶度积常数K_SP等计算三个体系中的平均离子活度系数(γ_±),发现γ_±值在(NH₄)₂HPO₄-H₂O体系中最大,在(NH₄)₃PO₄-H₂O体系中居中,在NH₄H₂PO₄-H₂O体系中最小,与溶解度规律一致。     

Synthesis of 4-aminopolymethoxycoumarins from 4-hydroxycoumarin triflates

4-Aminocoumarins were synthesized in high yields by the reaction of 4-hydroxycoumarin trifluoromethanesulfonates with amines. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1583–1588, September, 2006.     

Effects of Base for the Efficient Synthesis of 4-Formylcoumarins and 4-Formylcarbostyrils

The first efficient transformation of 4-bromomethylcoumarins and 4-bromomethylcarbostyrils to 4-formylcoumarins and 4-formylcarbostyril under aqueous conditions has been achieved by modifying the Kornblum method, resulting in excellent yield. The experimental method is very simple and economical; no further purification is required and the experimental conditions have been optimized. All the isolated compounds were characterized by infrared, NMR, and mass spectroscopy, and some of the compounds have been analyzed by single-crystal x-ray analysis.     

Dehydration of 4-hydroxy-4-methyl-3-phenylamino-oxazolidin-2-ones

The dehydration of two 5,5-disubstituted 4-hydroxy-4-methyl-3-phenylaminooxazolidin-2-ones into the corresponding 4-methylene-3-phenylaminooxazolidin-2-ones has been carried out. The structure of the products was confirmed by X-ray diffraction analysis.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1512–1517, October, 2004.     

A simple and efficient synthesis of optically pure 4-alkylisoxazolidin-4-ols

The reaction between N-hydroxyphthalimide and optically pure epichlorohydrin followed by addition of methanol represents a straightforward procedure for the synthesis of isoxazolidin-4-ols in high enantiomeric purity. Under the same conditions, the reaction of glycidyl arenesulfonates can lead to different products depending on the nature of the sulfonate. This property allowed the synthesis of both enantiomers of 4-methylisoxazolidin-4-ol from the same chiral epoxide starting material.     

2-烷硫基-5-苯基亚甲基-4H-咪唑啉-4-酮的合成与表征

用2-硫代-3-正丁基-5-苯基亚甲基4-咪唑啉二酮的-S-烷基化反应合成了2-烷硫基-3-正丁基-5-苯基亚甲基-4H-咪唑啉-4-酮衍生物。探讨了S-烷基化反应的反应条件和所合成化合物的波谱性质。目标产物均为新的化合物，其结构经元素分析，IR，1H NMR和MS确正。     

Facile Synthesis of 4-Oxo-4H-quinolizine-2-carboxamide Derivatives

A facile synthetic method for the construction of 2-substituted-4-oxo-4H-quinolizine-based core structure has been successfully developed. The synthesis made use of a one-pot Stobbe condensation followed by cyclization starting from the commercially available 2-pyridinecarbaldehyde. The structure of the formed 4-oxo-4H-quinolizine-2-carboxylate was fully confirmed by mass spectra, ¹H NMR and ¹³C NMR, correlation spectrography, heteronuclear multiple bond correlation, and heteronuclear single quantum coherence (HSQC) spectra. The ethyl carboxylate moiety was then further functionalized via direct aminolysis by a range of amines to afford the corresponding 4-oxo-4H-quinolizine-2-carboxamides 4a–i in moderate to good yields.     

Hydrogen bonds in 4-dihydroxymethylpyridinium 2,6-dichloro-4-nitrophenolate

The ionic adduct of 2,6-dichloro-4-nitrophenol with 4-formylpyridine (which transforms into 4-dihydroxymethylpyridine), crystallizes in the space group P2₁/c with a = 12.264(2), b = 6.730(1), c = 16.731(3) Å, β = 99.46(3)° and Z = 4. Relatively long N⁺---HO⁻ hydrogen bonds (R_N = 2.683(3) Å are formed with strongly asymmetric location of the H-atom. This is well reflected both in IR and UV-VIS spectra. One of the gem diol OH group is attached to the phenolate oxygen atom and the second is engaged in the formation of infinite polyanionic chains via O---HO hydrogen bonds between OH groups.