用核磁共振方法表征6(8)氨基-3H苯[1,2]氧嗪-1,4-二酮

用一维1HNMR、13CNMR方法研究了6(8)氨基-3H苯[1,2]氧嗪-1,4二-酮的结构,并通过二维1H-1H同核相关谱(COSY)、13C-1H异核相关谱(HMQC)及13C-1H异核远程相关谱(HMBC)进一步确定了该类化合物的1H谱和13C谱中各谱峰的归属,为研究同类化合物表征提供了依据。

Hydrothermal synthesis and structural characterization of a novel P-V-O layered compound [H(2)en](2)[H3O](6)[Co(H2O)(2)(VO)(8)(OH)(4)(PO4)8]

A new compound [H(2)en](2)[H3O](6)[Co(H2O)(2)(VO)(8)(OH)(4)(PO4)(8)] has been hydrothermally synthesized. Single crystal X-ray analysis indicates that this compound crystallizes in a monoclinic system, space group P2(1)/n with a=1.438 5(3) nm, b=1.012 2(2) nm, c=1.832 5(4) nm, beta=90.21degrees, V=2.668 2 (9) nm(3), Z = 2, D-c = 2.112 g/cm(3), R = 0.055, wR = 0.149 7, S = 1.037. The structure of [H(2)en](2)[H3O](6)[Co(H2O)(2)(VO)(8)(OH)(4)(PO4)(8)] is characterized by P-V-O layers constructed by [(VO)4 (OH)(2)(PO4)(4)](6-) non-symmetric units. The P-V-O layers are pillared by [Co(H2O)(2)](2+) group, resulting in the channels within which the protonated diaminoethane and H3O+ are located.

Investigation on nonradiative decay of the (Er3+I13/2)-I-4 -> I-4(15/2) transition in different tellurite glass matrix

Three kinds of Er3+-doped tellurite glasses with different hydroxyl groups are prepared by the conventional melt-quenching method. Infrared spectra are measured to estimate the exact content of OH- groups in samples. The maximum phonon energy in glasses are obtained by measuring the Raman scattering spectra. The strength parameters Omega(t) (t = 2, 4, 6) for all the samples are calculated and compared. The nonradiative decay rate of the Er3+ I-4(13/2) -> I-4(15/2) transition are calculated for the glass samples with different phonon energy and OH- group contents. Finally, the effect of OH- groups on fluorescence decay rate of Er3+ is analysed, the constant KOH-Er Of TWN, TZPL and TZL glasses are calculated to be 9.2 x 10(-19) cm(4)s(-1), 5.9 x 10(-19) cm(4)s(-1), and 3.5 x 10(-19) cm(4)s(-1), respectively.

Cr^4＋，Nd3＋共掺的钆镓石榴石（Cr，Nd：GGG）的光谱性能与光谱参数的研究

用提拉法生长了掺铬、钕的钆镓石榴石(Cr^4+，Nd^3+:GGG)晶体，研究了室温下的吸收光谱和荧光光谱性质，以及晶体中Cr离子浓度对Nd离子光谱性质的影响。应用Judd—ofelt理论计算了强度参数Ωt(t=2，4，6)，自发辐射跃迁几率、荧光分支比和辐射辱命等光谱参数。应用McCumber理论计算^4F3/2→^4I11/2能级跃迁的受激发射截面。结果表明：Cr^3+在300～900nm之间较强地增加了吸收截面，尤其是伴随Cr^3+→Nd^3+有效的能量转移。Cr^4+在1．06μm附近的吸收减弱了

Thiophene-NPN Ligand Supported Rare-Earth Metal Bis(alkyl) Complexes. Synthesis and Catalysis toward Highly trans-1,4 Selective Polymerization of Butadiene

A series of new rare-earth metal bis(alkyl) complexes [L(1-3)Ln(CH2SiMe3)(2)(THF)(n)] (L-1 = MeC4H2SCH2NC6H4(Ph)(2)P=NC6H2Me3-2,4,6: Ln = Sc, n = 1 (1a); Ln = Lu, n = 1 (1b); L-2 = MeC4H2SCH2NC6H4(Ph)(2)P=NC6H3Et2-2,6: Ln = Sc, n = 1 (2a); Ln = Lu, n = 1 (2b); Ln = Y, n = 1 (2c); L-3 = MeC4H2SCH2NC6H4(Ph)(2)P=(NC6H3Pr2)-Pr-i-2,6: Ln = Sc, n = 0 (3a)) and (LSc)-Sc-4(CH2SiMe3)(2()THF) (4a) (L-4 = C6H5CH2NC6H4(Ph)(2)P=NC6H3Et2-2,6) have been prepared by reaction of rare-earth metal tris(alkyl)s with the corresponding HL1-4 ligands via alkane elimination.

Highly 3,4-selective living polymerization of isoprene with rare earth metal fluorenyl N-heterocyclic carbene precursors

Fluorenyl modified N-heterocyclic carbene ligated rare earth metal bis(alkyl) complexes, (Flu-NHC)Ln(CH2SiMe3)2 (Flu-NHC = (C13H8CH2CH2(NCHCCHN)C6H2Me3-2,4,6); Ln = Sc (1a); Ln = Y (1b); Ln = Ho (1c); Ln = Lit (1d)), were synthesized and fully characterized by NMR and X-ray diffraction analyses. Complexes Ib-d with the activation of (AlBu3)-Bu-i and [Ph3C][B(C6F5)4] exhibited high activity, medium syndio-but remarkably high 3,4-regio-selectivity, and the unprecedented livingness for the polymerization of isoprene. Such distinguished catalytic performances could be maintained under various monomer-to-initiator ratios (500-5000) and broad polymerization temperatures (25-80 degrees C).

New rare earth metal bis(alkyl)s bearing an iminophosphonamido ligand. Synthesis and catalysis toward highly 3,4-selective polymerization of isoprene

Newrareearth metal bis(alkyl) complexes [(NPNPh)Ln(CH2SiMe3)(2)(THF) (NPNPh:N(Ph)PPh2=NC6H2Me3-2,4,6; Ln = Sc (3a), Ln = Y (3b), Ln = Lu (3c)) and [(NPNPy)Sc(CH2SiMe3)(2)(THF)1 (NPNPY = N(Py)PPh2=NC6H2Me3-2,4,6) (3d)) have been prepared via protonolysis reaction between rare earth metal tris(alkyl)s and the corresponding iminophosphonamines. Complexes 3a-d are analogous monomers of THF solvate. Each metal ion coordinates to a eta(2)-chelated NPN ligand and two cis-located alkyl groups, adopting tetrahedron geometry.

Non-isothermal crystallisation kinetics of polyamide 6/mesoporous silica nanocomposites

Non-isothermal crystallisation kinetics of a polyamide 6/mesoporous silica nanocomposite (PA6-MS) has been investigated by differential scanning calorimetry (DSC) at different cooling rates. Mandelkern, Jeziorny-Ziabicki and Ozawa methods were applied to describe this crystallisation process. The analyses show that the mesoporous silica particles act as nucleating agents in the composite and that the Avrami exponent n varies from 3.0 to 4.6. The addition of mesoporous silica influenced the mechanism of nucleation and the growth of polyamide 6 (PA6) crystallites.

1,4-二丙氧基-2,3二氰基萘的晶体结构

用 Siemens P4四圆衍射仪,测得了1,4-二丙氧基-2,3-二氰基萘的晶体结构。晶体属单斜晶系,空间群为 C2/C。晶格参数 a=14.987(3)A,b=10.527(2),c=11.755(2),β=118.98°(3),晶胞体积 V=1622.4(6)3,Z=4,Dc=1.205Kg/m~3,μ(MoK_α)=0.079mm~(-1),F(000)=624,T=293(2)K_o晶体结构应用直接法,解出最后的偏离因子 R=0.0554[1425个Ⅰ≥2σ(Ⅰ)衍射点]。结构分析表明,萘环的1,4和2,3位碳原子上的氢原子分别被丙氧基和氰基所取代,由于取代基的引入使萘环的结构有所改变。

LUMINESCENCE AND ENERGY-TRANSFER OF RARE-EARTH-METAL IONS IN MG2Y8(SIO4)(6)O-2

The photoluminescence of Ce3+, Tb3+ and Sm3+, and energy transfer from Ce3+ to Tb3+, Dy3+ and Sm3+ in Mg2Y8(SiOd(4))(6)O-2 are reported and discussed. The Ce3+ ion shows blue luminescence under UV excitation, and occupies simultaneously the 4f site and 6h site in the host lattice. The optimum concentrations for the D-5(3) and D-5(4) emissions of Tb3+ and the (4)G(5/2) emission of Sm3+ are determined to be 0.04, 0.20 and 0.10 mol in every mol of Mg2Y8(SiO4)(6)O-2, respectively. The critical distances responsible for the cross-relaxation between the D-5(3)-D-5(4) and F-7(6)-F-7(0) transitions of Tb3+ and between the (4)G(5/2)-F-4(9/2) and H-6(5/2)-F-4(9/2) transitions of Sm3+ are estimated to be 1.43 and 1.06 nm, respectively. Both Tb3+ and Dy3+ can be sensitized by Ce3+, but Ce3+ and Sm3+ quench each other.

ISOPOLYMOLYBDIC ACID-POLY(4-VINYL)PYRIDINE FILM MODIFIED ELECTRODE

Electrochemical polymerization of 4-vinylpyridine produced a uniform poly(4-vinyl)pyridine(PVP) film on the glassy carbon (GC) electrode surface. The isopolymolybdic acid-PVP film-modified electrode was prepared by soaking the PVP/GC electrode in the 0.05 M H2SO4 aqueous solution containing 0.005 M isopolymolybdic acid (H4Mo8O26). The latter (catalyst) is incorporated and held in the PVP film electrostatically. The electrochemical behavior and electrocatalytic properties of this H4Mo8O26-PVP/GC electrode was described. The results indicate that this modified electrode has good stability and electrocatalytic activity on the reduction of chlorate and bromate ions in aqueous solution. The catalytic process is regarded as an EC mechanism.

Catena-Poly[[[tetra-mu(2)-aqua-heptaaqua-(mu(2)-benzene-1,3,5-tricarboxylato)-mu(3)-hydroxido-trinickel(II)sodium]-mu(4)-benzene-1,3,5-tricarboxylato]sesqui-hydrate]

The title coordination polymer, {[Ni3Na(OH)(C9H3O6)(2)( H2O)(11)] center dot 1.5H(2)O}(n), is built up from three independent Ni-II ions and one Na-I cation bridged by benzene-2,4,6-tricarboxylate ( BTC) ligands and water molecules. Three Ni-II ions are bridged by three bidentate carboxylate groups of three BTC ligands, two aqua ligands and one OH- unit, to form a trinuclear metal cluster. The Na-I cation is bonded to the Ni-II cluster by two bridging water molecules. One of the three BTC ligands bridges neighbouring clusters into one-dimensional chains, which are further connected through a complex hydrogen-bonding scheme, forming a three-dimensional suprastructure. The title complex is isomorphous with the previously reported Co-II complex.

HPLC测定四川及青海地区獐牙菜植物中6种主要成分的含量

目的:建立反相高效液相色谱法同时测定四川及青海地区部分獐牙菜中獐牙菜苦苷、龙胆苦苷、芒果苷、当药醇苷、异荭草苷、1,8-二羟基-3-甲氧基(口山)酮的含量.方法:采用RP-HPLC,使用Kromasil C_(18)(4.6 mm×250mm,5 μm)柱;流动相甲醇-水(含0.02%磷酸);梯度洗脱程序为0～50 min,甲醇的体积分数(下同)由20%上升至80%;50～55 min由80%增至100%,55～60 min为100%,流速1 mL•min~(-1),检测波长254 nm;柱温35 ℃.结果:6种成分均达到基线分离,线性良好.结论:该方法快速、准确、重复性好,为该类药材的入药提供了理论依据.

HPLC法测定野生与栽培藏药麻花艽中4种环烯醚萜苷类成分的含量

目的：对野生和栽培藏药麻花艽中龙胆苦苷、落干酸、獐牙菜苦苷和獐牙菜苷4种苦苷类成分进行高效液相色谱的含量测定，并比较分析它们之间的差异。方法：采用Eelipse XDB-C_8色潜柱(4.6 mm*150 mm，5 μm)，流动相A为95％乙腈水溶液，B为5％乙腈(含10 mmol•L~(-1)的甲酸)水溶液，A在0-20min内比例由0-100％进行线性洗脱，流速1.0 mL•min~(-1)，检测波长240 nm，柱温30℃。结果：4种成分均达到基线分离，龙胆菁苷、落干酸、獐牙菜苦苷、獐牙菜苷的线性范围分别为0.60～19•20μg(r=0.9999)，0.24～7.68μg(r=O.9999)，0.38-12.02μg(r=O.9999)，0.05～1.66μg(r=0.9999)；回收率分别为99.73％，98.13％，98.45％，96.22％。结论：栽培藏药麻花艽中苦苷类成分的含量已经接近或超过野生种的水平，可初步代替野生药材人药。