Study of the Complexation Behavior of Calixarene with Transition Metal Cations by UV—vis and Fluorescent Spectra

A new fluorescent compound based on calix[4] arene skeleton was synthesized.Its complexation ability with transition metal ions,such as Fe^3 ,Co^2 ,Ni^2 ,Cu^2 ,Zn^2 and Ag^ ,Was investigated by UV-vis and fluorescent spectra.     

反对数微分简易示波伏安法的研究

在获得微分简易地波伏安图的实验线路中,增加了反对数装置,提出了反对数微分简易示波伏安法。该方法被应用于铝合金中微量铜和分子筛中微量钴的测定,获得了满意结果。     

Rhodium(I)‐Catalyzed [4 + 2] Cycloaddition Reactions of 2‐Alkylenecyclo‐butanols with Alkynes and (E)‐2‐Nitroethenylbenzene through C(sp2)—C(sp3) Bond Cleavage

An intermolecular [4 + 2] cycloaddition was realized through C—C bond cleavage in the presence of Rh(I) catalyst. The selective ring opening of 2‐alkylenecyclobutanols enables the generation of active alkenylrhodium species, which underwent smooth cross addition over alkynes and (E)‐2‐nitroethenylbenzene, leading to highly substituted all‐carbon six‐membered rings in a single step and in a complete atom economy.     

正已醇-邻、间、对二甲苯二元系固液相平衡

Melting temperatures have been measured and the solid-liquid phase diagrams constructed for 1-hexanol＋o-xylene, 1-hexanol＋m-xylene and 1-hexanol＋p-xylene. They are simple eutectic systems. Excess mole Gibbs free energies were calculated at 298.15K, showing larger positive deviations from ideal-solution behavior. The largest values of GmE are 711、 650 and 800 J•mol-1 for {o-C6H4(CH3)2＋C6H13OH}、 {m-C6H4(CH3)2 ＋ C6H13OH} and {p-C6H4(CH3)2＋C6H13OH} respectively.     

The designed synthesis and characterization of two novel heterometallic trinuclear incomplete cubane-like clusters [(CH3CH2)4N]{(M2CuS4)}(S2C2H4)2(PPh3) (M = Mo, W)

Two novel heterometallic trinuclear incomplete cubane-like clusters [(CH₃CH₂)₄N][{M₂CuS₄}(edt)₂(PPh₃)] (M = Mo, W) have been synthesized by reaction of [(CH₃CH₂)₄N]₂[M₂S₄(edt)₂] (M = Mo, W) with Cu(PPh₃)₂(dtp) [where edt is 1,2-ethane-dithiolato ligand, dtp is S₂P(OCH₂CH₃)₂⁻]. The two crystals are isomorphous in space group P1 (No. 1). The unit cell contains two independent molecules, but the two discrete anions have the same orientation for the PPh₃ ligands along one axis so the space group is undoubtedly non-centrosymmetric. The discrete anion contains two edt ligands and one PPh₃ ligand attached to one incomplete cubane-like cluster core {M₂CuS₄}³⁺ (M = Mo, W). The bond lengths of Mo---Mo[W---W] and the two Mo---Cu[W-Cu] are 2.852(2)[2.844(1)], 2.802(2)[2.765(3)], 2.760(2)[2.762(3)] Å, respectively. The M ₂S₄(edt)₂ (M = Mo, W) moiety remains almost unchanged, except that for the compound 1 the Mo=S double bond length elongates from av. 2.10 to av. 2.165 Å. The title clusters provide a new type of unsymmetric μ₂-bridging sulphido ligand. The incomplete cubane-like cluster core {Mo₂CuS₄}³⁺ of compound 1 is distorted because the two Cu---μ₂---S bond lengths are significantly different (2.313 Å and 2.409 Å), but the core {W₂CuS₄}³⁺ of compound 2 has approximately C_s symmetry. The IR spectra of the two title clusters and two starting materials are assigned.     

Diffusion characteristics of a T-type microchannel with different configurations and inlet angles.

A series of symmetrical and asymmetrical microfluidic T-sensors with different inlet angles were fabricated to study the mixing characteristics of a T-type microstructure for generating concentration gradient. Computational fluid dynamics (CFD) simulations showed that the concentration gradient, transition zone and diffusion length were different for various configurations and inlet angles. Quick mix and sharp concentration gradient occurred in the asymmetrical structure with large inlet angle. The observed concentration gradients in the fabricated microchannel were consistent with the theoretical prediction. In this microstructure, stagnant zone and z-direction diffusion also affected the concentration gradient. Based on the simulation results, the microfluidic structure was optimized to generate desired concentration gradient for a cell-based study.     

Chemiluminescence Determination of Benzoic Acid Using A Solid-Phase Verdigris Reactor

Benzoicacidisacommonadditiveusedwidelyasfoodpreservativeandplasticizer.Itcouldpromoteseverereactiontoallergicpopulationevenatlowconcentrationlevel1.Routinemethodsfortheassayofbenzoicacidincludeschromatographic2-6,spectrophotometry7,8,capillaryelectrophoresis9-13andelectrochemicaltitration14.Stokes15etal.monitoredairbornebenzoicacidbasedonsurface-enhancedRamanscatteringtechniques.Thereisalsoreportonamicrobialsensorusingpseudomonasforbenzoicacidandtheirderivativesinaqua16.Interestofusinglumines…     

A New Asterosaponin from the Starfish Culcita novaeguineae

A new asterosaponin named novaeguinoside A, along with a known saponin, asteronyl pentaglycoside sulfate, was isolated from the starfish Culcita novaeguineae. The new compound was identitied to be sodium 6α-O-{β-D-fucopyranosyl-(1→2)-β-D-fucopyranosyl-(1→4)-[β-D-quinovopyranosyl-(1→2)]-β-D-xylopyranosyl-(1→3)-[β-D-quinovopyranosyl}-5α-pregn-9(11)-en-20-one-3β-yl-sulfate by extensive spectral analysis and chemical evidence.