Self‐assembly synthesis and structure of mono‐ and di‐nuclear uranyl complex

Mixing the malonate (mal), 4,4′‐bipyridine, UO₂(CH₃COO)₂ · 2H₂O in different solvent condition gets two compounds (bpy)₂(H₂bpy)[UO₂(mal)₂(μ‐H₂O)] · 8H₂O (1) and (H₂bpy)[UO₂(mal)₂] · 2H₂O (2) . Both complexes contain seven‐coordinated pentagonal bipyramidal uranium center. Crystal 1 is mononuclear structure and crystal 2 contains dinuclear [(UO₂)₂(mal)₂(μ₂‐mal)₂]^4‐ subunit. Particularly, Crystal 2 forms the twodimensional supramolecular topology by hydrogen bonds. The sheet constructs from two sorts of chamber, of which the larger one has two water molecular guests. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

二维气相色谱技术及其在烟草行业中的应用

二维气相色谱的应用大大提高了分析能力,而与飞行时间质谱的联用更使其达到一个新的高度。介绍了二维气相色谱的原理、优越性及不足,以及与飞行时间质谱联用的技术进展。综述了近年来该技术在各行业特别在烟草行业中的应用,展望了二维气相色谱在烟草行业中的应用前景。     

Synthesis and Crystal Structure of a New Copper–PMIDA Compound (H4PMIDA=H2O3PCH2N(CH2CO2H)2)

A new Cu(II)PMIDA compound [Cu(H₂PMIDA)(phen)] 3H₂O (1) (H₄PMIDA = H₂O₃PCH₂N (CH₂CO₂H)₂,phen = 1,10-phenanthroline) has been successfully synthesized and structurally characterized. In complex 1, Cu (II) is six coordinated by chelation in a tetradentate fashion by a PMIDA ligand and by two N atoms of a phen ligand. Every phen–Cu(II)–PMIDA group connects with each other via a hydrogen bond and the edge-to-face -stacking interaction. Complex 1 crystallized in triclinic P-1 with cell dimensions of a = 7.5817(6) Å, b = 10.6980(8) Å, c = 13.1852(10) Å, =82.350(2)°, = 84.151(2)°, =78.4250(2), V= 1035.25(14) ų, Z = 2, Dc = 1.677 Mg/m³.     

Solvothermal Synthesis and Structure of Two 2D Tin–Selenides with Long Alkyldiamine NH2(CH2) n NH2 (n = 8, 10)

Reactions of NH₂(CH₂) _n NH₂ (n = 8,10) with elemental Sn and Se in a H₂O/CH₃OH mixture at 150°C afford two compounds (NH₃(CH₂)₈NH₃)Sn₃Se₇ (1) and (NH₃(CH₂)₈NH₃)Sn₃Se₇ (2). The crystal structures were determined by single crystal X-ray diffraction at room temperature. Both compounds exhibit the same anionic structure—a 6³ netted plane composed of [Sn₃Se₇]^2– subunits. The distance between the centers of crystal 1 layers is 7.5 Å, somewhat shorter than the distance (8.5 Å) in crystal 2.     

固相微萃取/加速溶剂萃取-气相色谱-质谱法分析青山绿水茶叶的挥发性成分

采用固相微萃取(SPME)和加速溶剂萃取(ASE)两种前处理方法从青山绿水茶叶(也叫苦丁茶)中提取挥发性成分,用气相色谱-质谱法(GC-MS)定性。实验结果表明:两种前处理方法共检测出91种成分,SPME检出49种,ASE检出56种,共同组分14种。青山绿水茶叶的挥发性成分主要成分有β-月桂烯、3,3,5-三甲基-1,5-庚二烯、L-柠檬烯、α-罗勒烯、β-罗勒烯、β-蒎烯、2-甲基安息香醛和5-羟甲基糠醛等物质。这两种提取方法各具优势,共同应用可以起到取长补短的作用。     

Synthesis and structure of a new one‐dimensional cobalt complex with dicyanamide and 4‐picolyl choride bridges

The synthesis and structure of the 1D cobalt (II) complex, [Co( L )₂(dca)₂] ( 1 ) (dca = dicyanamide, C₂N₃^–, L = 4‐picolyl choride) is reported. Complex 1 crystallized in triclinic system, space group P ‐1, with cell dimensions of a = 7.291(2) Å, b = 7.481(2) Å, c = 9.007(3) Å, α =104.444(4)°, β = 96.971(4)°, γ =102.618(4)°, V = 456.1(2) ų, Z = 1, Dc = 1.624 Mg/m³. In complex 1 , Co (II) is 6‐coordinated by N atoms of four dca ligands and two L ligands. The centrosymmetric CoN6 chromophore is an axially elongated octahedron that has Co‐N distances ranging from 2.122(3) to 2.154(3) Å. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

超高效液相色谱法测定烟用香精中的欧前胡素

建立了测定烟用香精中欧前胡素的超高效液相色谱方法.以体积比为1∶1的乙腈-水溶液为萃取剂,采用ACQUITY UPLC(R)BEH C18(50 mm×2.1mm,1.7 μm)色谱柱,柱温为30℃,流动相为乙腈-水,进行梯度洗脱,流速为0.2 mL/min,检测波长为248 nm,对20种烟用香精样品进行测定.欧前胡...     

Synthesis and structure of a three-dimensional coordination polymer [Ag<Subscript>3</Subscript>hmt<Subscript>3</Subscript>(μ<Subscript>3</Subscript>-btc)]·5H<Subscript>2</Subscript>O

A new coordination polymer [Ag₃hmt₃(₃-btc)]·5H₂O (1 )(hmt = hexamethylenetetramine, btc = 1,3,5-benzenetricarboxyl)has been successfully synthesized. Crystal data: P2₁/a , a = 11.9906(2) Å, b = 17.3689(2) Å, c = 16.96100(10) Å, = 101.9820(14)°, V = 3455.40(7) ų, Z = 4, Dc = 2.002 mg/m³. In the hexagonal structure of the Ag-hmt unit, each Ag-hmt unit comprises three Ag atoms and three hmt ligands. The ₃-btc ligands bridge the adjacent two-dimensional honeycomb-like Ag-hmt layers to form three-dimensional networks. Structural analysis shows that hydrogen bonds play a key role for the structural stability of the compounds.Original Russian Text Copyright © 2004 by Shoubo Qin, Sheming Lu, Yanxiong Ke, Jianmin Li, Shuxi Zhou, Xintao Wu, and Wenxin DuTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 3, pp. 566–571, May–June 2004.     

Influence of soaking duration on the selective oxidation and galvanizability of a high‐strength dual phase steel

High‐strength dual phase steels readily exhibit bad galvanizability and coating defects because of selective oxides formed on steel surface during the annealing process prior to galvanizing. To investigate selective oxidation of alloying elements and their effects on glavanizability, a high‐strength dual phase steel was annealed with soaking duration for 45, 90, and 120 s, respectively, and then galvanized using a hot‐dip simulator. Field‐emission scanning electron microscopy characterization revealed that when dual phase steel was soaked for 45 s, selective oxides mainly precipitated along grain boundaries, while only a few of the oxides formed on grains. With soaking duration increased, oxides were so dense that nearly all steel surface was covered, leaving little bare area of the steel surface. Further XPS analysis showed that selective oxides mainly consisted of MnO and Cr₂O₃. In addition, the chemical nature of oxides did not change at all although soaking duration prolonged. Scanning Auger microprobe depth profiles presented that Mn had a much higher tendency to segregate than Cr and Mo. Oxygen penetration depth to subsurface was promoted as soaking duration increased. The formation of interfacial inhibition layer was founded to be greatly influenced by the density and size of surface oxides. The widely spaced small oxides had virtually no adverse effect on wettability because of aluminothermic reduction of oxides by the bath dissolved Al. As the oxides became dense and considerably big, the grains of the inhibition layer in some certain zones became coarse and the galvanizability tended to deteriorate. Copyright © 2011 John Wiley & Sons, Ltd.     

气相色谱-负化学电离源-飞行时间质谱测定烟草中有机氯农药残留

采用QuEChERS前处理方法,建立了气相色谱-负化学电离源-飞行时间质谱(GC-NCI-TOF-MS)检测烟草中10种有机氯农药残留的分析方法。样品采用乙酸乙酯-正己烷(1 : 1, v/v)溶液提取,提取液经N-丙基乙二胺(PSA)、无水硫酸镁分散固相萃取净化,用GC-NCI-TOF-MS检测分析。根据有机氯化合物特征离子的精确质量数、同位素离子峰簇、碎片离子丰度比和保留时间对目标物定性鉴定,外标法定量。10种有机氯农药的线性关系良好,相关系数 (r²)均大于0.997;相对标准偏差小于6.5%;检出限为0.04~0.80 μ g/kg;加标回收率为77.2%~93.0%。该方法简单快速、灵敏度高、准确性好,适用于烟草中有机氯农药残留的定性分析和定量检测。