Synthesis,crystal structure and conformational analysis of an unexpected [1,5]dithiocine product of aminopyridine and thiovanillin

The condensation reaction of 2‐mercapto‐3‐methoxybenzaldehyde with 3‐aminopyridine afforded an unexpected N‐alkylated [1,5]dithiocine instead of the N‐salicylideneaniline. The proposed mechanism for this condensation involves a strong intramolecular hydrogen bond between the thiol and the amine groups, leading to a second condensation. The corresponding product, i.e. 4,10‐dimethoxy‐13‐(pyridin‐3‐yl)‐6H,12H‐6,12‐epiminodibenzo[b,f][1,5]dithiocine methanol 0.463‐solvate, C₂₁H₁₈N₂O₂S₂·0.463CH₃OH, was characterized by single‐crystal X‐ray diffraction analysis. The supramolecular structure shows π–π stacking and S…S interactions in the crystal packing. Within the asymmetric unit, two geometries of the N atom are observed. Although a planar geometry should be expected, a pyramidal one is observed due to the crystal packing. The presence of the two geometries was further supported by density functional theory (DFT) calculations that show an electronic energy difference of less than 2 kJ mol^?1 between the two conformers.     

The Synthesis of 2‐(Chromon‐2/3‐yl)‐3‐(5‐thione‐4‐hydro‐1,3,4‐thiadiazol‐2‐yl)‐4‐oxo‐thiazolidine

2‐Formylchromones and 3‐formylchromones as the first materials singly reacted with 2‐amino‐5‐mercapto‐1,3,4‐thiadiazole to give the corresponding Schiff bases, which on cyclocondensation with mercapto‐acetic acid in 1,4‐dioxane yielded target compounds named 4‐oxo‐thiazolidines. The structures of all the synthetic compounds were confirmed by elemental analysis and IR, ¹H NMR, LC‐MS (ESI) spectral data.     

四磺基钴酞菁/MCM-41的制备、表征及其催化性能

将四磺基钴酞菁（CoTSPc）通过共价结合连接在氨基化的介孔分子筛MCM-41孔道壁上，制成负载酞菁催化剂，对其进行了X射线衍射（XRD）和红外分析，并研究了其对巯基乙醇的催化氧化反应动力学．结果表明，负载酞菁催化剂有优良的催化性能，在液相反应过程中扩散阻力较小．这种负载催化剂有酶催化特点，即遵循米氏动力学规律，米氏常数Km为0．015mol／L．反应完成后，通过沉淀即可从反应体系中分离，解决了酞菁催化剂无法回收利用和对环境造成新的污染的问题．在工业生产和环境保护方面有着良好应用前景．     

“推-拉”型巯基偶氮苯衍生物的合成

分子电子器件的研究是近期基础研究中受到极大关注的前沿热点[1-4]。带巯基的有机分子在金电极表面形成的自组装单分子膜(SAMs)及其电活性,是分子电子学领域具有代表性和研究最多的体系之一[5-13]。由于结构的特殊性和特征的光致异构化,偶氮苯衍生物具有对光和电的双重活性[14]     

2—（4,6—二甲基—2—嘧啶巯基）乙酰芳胺的合成及其生物活性的初步研究

许多乙酰芳胺类化合物具有优异的生物活性，例如除草剂苯噻草胺，可抑制细胞生长和分裂，防除稻田中禾本科杂草［１］；杀菌剂甲霜灵可防治作物霜霉病［２］。本文将具有多种生物活性的嘧啶基团引入到乙酰芳胺结构中［３］，合成下列１０个未见文献报道的标题化合物Ⅰ，通...     

MMI作为铜的盐酸酸洗缓蚀剂作用机理的研究

用失重法研究了N-甲基-2-巯基咪唑（MMI）在5％盐酸中对铜的酸洗缓蚀性能.探讨了温度和MMI浓度对缓蚀效果的影响，从中得出了MMI在铜表面的吸附等温式，计算了吸附热及MMI的加入对铜在盐酸中腐蚀反应活化能的影响，进而探讨了MMI对铜缓蚀作用的机理.结果表明， 30 ℃下，在5％盐酸中，当MMI的浓度在3 mmol•L－1和8 mmol•L－1之间时,缓蚀率随MMI浓度的增加而迅速增加，当浓度达到8 mmol•L－1时，缓蚀率趋于定值，而当浓度小于3 mmol•L－1时， MMI的加入会加速铜的腐蚀；吸附在铜表面的MMI分子间的作用力整体表现为引力； MMI在铜表面的吸附是吸热反应； MMI的加入降低了铜的腐蚀反应活化能.     

2-取代苯并噁唑衍生物的合成及生物活性

苯并唑类化合物具有广泛的生物活性 ,在农业上用作杀菌[1 ] 、除草[2 ] 和杀虫剂[3] 都有报道 ,对这类化合物的修饰主要是在苯环上引入不同的取代基 ,或在 2位上引入不同的杂环和其它活性基团 ,其中2位上的取代基对生物活性影响最大。同时还有文献报道了许多杂环硫醚类化合物表现出除草和杀菌活性[4～ 7] ;杂环取代的硫乙酰胺类化合物有很好的除草活性[8] 。因此 ,本文在 2 巯基苯并唑的 2位上引入不同的烷基和N 取代的乙酰胺 ,以期能发现活性好的化合物 ,并分别对它们进行了杀菌和除草活性的研究。合成路线如下 :2a .R =CH2 CH3 ;2…     

Transition metal derivatives of 3-4-diphenyl-5-mercapto-l,2,4-triazole

Neutral chelates of 3,4-diphenyl-5-mercapto-l,2,4-triazole (DPMTH) with Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) have been prepared and characterized by analytical and physicochemical techniques such as magnetic susceptibility measurements, TGA, electronic ESR and IR spectral studies. The IR data suggest that DPMTH behaves as a uninegative bidentate ligand in all the complexes except Fe(II) and Ni(II) where it is tridentate. The complexes have been found to display significant antifugal activity againstA. ahernata andA. flavus.     

巯基膨润土的制备工艺及性能

为了简化巯基膨润土(Bent-SH)的制备工艺、降低制备成本以便于实际应用,用3-巯丙基三甲氧基硅烷(MPS)与硅酸钠协同改性膨润土(Bent)。 优化了Bent-SH的工艺条件、表征了Bent-SH的结构、测定了Bent-SH的性能。 最佳制备工艺为:Bent与MPS的用量比为1∶0.05(g/mL);m(Na₂SiO₃)∶m(Bent)=7.0∶100;固液比为1∶20(g/mL);改性悬浮液的最佳pH值为8.0～10.0;改性时间为5～6 h,反应温度为室温。 Bent-SH较Bent胶质价、膨胀倍和阳离子交换容量均有所下降,但Bent-SH对镉的饱和吸附容量为20.86 mg/g,比Bent提高了20多倍。 硅酸钠和MPS协同改性没有改变Bent层状结构,而显著增强了Bent-SH的疏水性,分散性及对镉的吸附容量和吸附选择性。 Bent-SH是一种具有应用前景的重金属污染土壤的钝化剂。     

Recovery of Uranium(VI) from Sulfate Leach Liquor using Modified Duolite

Silicate mercapto Duolite composite ( SMDC ) and activated Duolite A 101 D ( AD ) were prepared, characterized, and tested for uranium removal from sulfate solution using batch experiment technique. The capability of newly adsorbents for sorption of uranium was estimated and optimized under different controlling variables, including the impact of uranium initial concentration, pH of the medium, equilibrium time, temperatures, dose and interfering ions. Testing of different adsorbents for adsorption isotherms revealed that the achieved experimental data were fitting well with the Langmuir isotherm model with 68.02 mg · g^–1 and 208.33 mg · g^–1 as theoretical capacity for AD and SMDC , respectively. Thermodynamic parameters have been resulted in negative values for ΔH and ΔS indicating an exothermic and decreased randomness behavior for uranium(VI) adsorption, while negative values of ΔG indicate spontaneous uranium adsorption. The kinetics studies showed that the adsorption process was controlled expressed by pseudo-second order model. Finally, the optimized factors have been applied for uranium(VI) recovery from Gattar leach liquor producing a uranium concentrate (Na₂U₂O₇) with uranium concentration of 70 % and purity of 93.33 %.