一种新颖有机-无机杂化配位聚合物[(C10H16N)2（Pb2I6）·2DMF·H2O]n的自组装合成和晶体结构(英)

A novel coordination polymer [(C₁₀H₁₆N)₂（Pb₂I₆）·2DMF·H₂O]_n (C₁₀H₁₆N=N-butyl-2-Methy-Pyridinium) was synthesized by the reaction of Pb(NO₃)₂ with C₆H₁₀NI at room temperature in DMF solvent and structurally characterized by means of X-ray single diffraction. The title compound crystallizes in triclinic system, space group P1 with a=1.1237(2) nm, b=1.25330(16) nm, c=0.808 00(12) nm, α=102.523(4)°, β=92.475(5)°, γ=95.712(10)°, V=1.102 9(3) nm³, Z=1, D_c=2.470 Mg·m^-3, F(000)=738, chemical formula C₂₆H₄₈N₄O₃Pb₂I₆ and M_r=1 640.46, μ（MoKα）=11.849 mm^-1, the final R=0.057 8 and wR=0.166 5 for 3716 observed reflections with I > 2σ(I). The title compound consists of cations ([(C₁₀H₁₆N)⁺] and anion chain(PbI₃^-),they are combined by static attracting forces in the crystal. DMF and H₂O locate between the organic and inorganic moiety. CCDC: 210812.     

Zur Kenntnis des Natrium-tetrahydroxoaluminat-chlorids Na2[Al(OH)4]Cl

On the Sodium Tetrahydroxoaluminate Chloride Na₂[Al(OH)₄]Cl The hitherto unknown compound Na₂[Al(OH)₄]Cl was prepared by crystallisation from a NaCl containing sodium aluminate solution. According to the X-ray single crystal investigation (tetragonal, space group P4/nmm, a = 7.541 Å, c = 5.059 Å, Z = 2) the compound represents the first example of a crystalline hydroxoaluminate with monomeric [Al(OH)₄]^? anions. Cl^? shows a quadratic anti prismatic coordination to 4 Na⁺ and over hydrogen bonds to 4 O^2? while Na⁺ is octahedrally coordinated by 4 O^2? and 2 Cl^? (axial). The results of the crystal structure analysis are confirmed by ²⁷Al and ²³Na MAS NMR investigations. Na₂[Al(OH)₄]Cl decomposes at about 200°C without intermediates under formation of β-NaAlO₂ and NaCl.     

1570例学龄前儿童血铅水平调查

为了解顺德伦教学龄前儿童血铅水平及铅中毒发病情况 ,以便及时采取有效措施 ,根据整群分层随机抽样 ,检测了本区学龄前儿童血铅水平 ,并进行了流行病学分析。结果表明 ,本次调查学龄前儿童 1 5 70例 ,血铅水平为 (1 0 8 6± 79 8) μg/L ,儿童铅中毒患病率为 5 0 76% ;男童血铅水平及铅中毒患病率都高于女童 ,但无明显统计学差异 (P >0 0 5 ) ;年龄越大血铅水平相对越高 ,铅中毒患病率也越高 ,并存在明显差异 (P <0 0 1 )。提示顺德伦教学龄前儿童血铅水平及铅中毒患病率维持在较高水平 ,应及时采取有效措施 ,防治儿童铅中毒。     

Et2NH2[Nd(S2CNEt2)4]的晶体结构和生成反应焓变

在干燥氮气气氛下,以无水乙醇为溶剂,制备了低水合氯化钕与二乙氨基荒酸二乙铵(D-DDC)配合物,确定其组成为Et2NH2[Nd(S2CNEt2)4].单晶结构分析表明,配合物中4个二乙氨基荒酸根各通过2个硫原子与钕离子成键形成八配位十二面体阴离子,并与二乙铵阳离子形成缔合型分子.晶体属单斜晶系,空间群P21/n,a=1.37517(14)nm,b=2.1146(2)nm,c=1.44641(15)nm,β=102.028(2)°,Z=4.用微量热法测定了298.15K下水合氯化钕和D-DDC在无水乙醇中的溶解焓及二乙氨基荒酸钕液相生成反应焓变分别为(-17.89±0.096),(50.280±0.151)和(-10.116±0.065)kJ/mol,求得固相生成反应焓变.     

Three-component catalytic method for synthesis of α-amino phosphonates with the use of α-amino acids as amine component

Interaction of aliphatic and aromatic aldehydes and ketones with optically active L-α-amino acids or their esters in the three-component catalytic one-pot synthesis of α-aminophosphonates was studied. The corresponding α-amino phosphonates are formed in high yields as mixtures of diastereomers. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 768–774, April, 2007.     

Inhibition of Pb-Leaching from Lead Crystal Glass by Coating with Films Prepared by the Sol-Gel Method

The chemical durability of lead glass tumblers (24% PbO) in a 4% (v/v) acetic acid solution before and after coating with sol-gel derived SiO2 films was assessed to determine the extent of reduction in Pb-leaching that can be achieved. It was found that by coating the internal surface of the glass tumblers with 1 ml of 10% TEOS solutions at 100°C and densifying the coating formed at 500°C for 1 h, it was possible to reduce Pb-leaching to about one quarter of that of the uncoated glass.     

Enthalpies of dilution of electrolyte solutions by flow microcalorimetry

The enthalpies of dilution of NaCl, Me₄NBr, andn-Bu₄NBr were measured in water at 25°C with a new flow microcalorimeter. The data were analyzed with a polynomial equation, and the derived relative apparent molal enthalpies _L are in good agreement with literature values. Provided care is taken that mixing is complete, flow calorimeters are as reliable and much less time-consuming than cell-type instruments for enthalpies of dilution measurements.     

An unprecedented N-transacylation reaction on 2-acetamido-2-deoxy-α-d-glucopyranosides

An unprecedented N-transacylation reaction on 2-acetamido-2-deoxy-α-d-glucopyranosides was disclosed in the presence of acyl chloride and DMAP under reflux in pyridine.     

PHOTO-INDUCED DOPED POLYANILINE BY THE VINYLIDENE CHLORIDE AND METHYL ACRYLATE COPOLYMER AS PHOTO ACID GENERATOR

The emeraldine base form of polyaniline (PANI) can be doped by a photo-induceddoping method. In this method a copolymer of vinylidene chloride and methyl acrylate(VCMAC) was used as photo acid generator which can release proton when it is exposedto ultraviolet light (λ= 254 nm). The structure of PANI-VCMAC system before and afterirradiation was characterized by elemental analysis, IR, XPS, and SEM images. Resultsobtained indicate that the photo-induced doping characteristics, such as doping positionand type of charge carriers, are similar to that of PANI doped with HCl. The poor room-temperature conductivity (～10~(-5)S/cm) of PANI-VCMAC system after irradiation maybe due to low doping degree (～pH= 3) and the difference in morphology as compared withPANI-HCl film.     

Conductance studies in amide-water mixtures. II. Sodium salts inN,N-dimethylformamide-water mixtures at 35°C

Conductance data for sodium nitrite, chloride, and acetate in water andN,N-dimethylformamide (DMF)-water mixtures (74.82D42.48) for the concentration range 0.001–0.04N, as well as the densities, viscosities, and dielectric constants of the solvent mixtures at 35°C, are reported. The data have been analyzed by the Fuoss (1975) equation. The existence of a maximum in the viscosity at a 13 mole ratio of DMF and water is indicated. The Walden products for all the three salts pass through a maximum while the equivalent conductances show a minimum with increasing DMF content. The maxima in the Walden product are attributed to the dehydration of ions by the cosolvent (DMF).Part I:Indian J. Chem. 14A, 1015 (1976).Deceased.