A chloride-anion insensitive colorimetric chemosensor for trinitrobenzene and picric acid

A new receptor, the bisTTF-calix[2]thiophene[2]pyrrole derivative 3, has been prepared from the Lewis acid-catalyzed condensation of 2,5-bis(1-hydroxymethylethyl)thiopheno-TTF and pyrrole. This new system is found to form complexes with the electron-deficient guests, trinitrobenzene (TNB) and picric acid (PA), which serve as models for nitroaromatic explosives. The binding phenomenon, which has been studied in organic solution using proton nuclear magnetic resonance and absorption spectroscopies, results in an easy-to-visualize color change in chloroform that is independent of the presence of chloride anion, a known interferant for an earlier tetrakisTTF-calix[4]pyrrole TNB chemosensor. Support for the proposed binding mode comes from a preliminary solid state structure of the complex formed from TNB, namely TNB⊂3. A color change is also observed when dichloromethane solutions of chemosensor 3 are added to solvent-free samples of TNB, PA, and 2,4,6-trinitrotoluene supported on silica gel. Figure A new bis-tetrathiafulvalene calix[2]thiophene[2]pyrrole derivative has been prepared that gives rise to an easy-to-visualize color change in the presence of the model nitroaromatic explosives trinitrobenzene and picric acid. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.

Retroperitoneal ancient schwannoma presenting as an adrenal incidentaloma: CT and MR findings

A 35-year-old woman was referred to our institution for additional examinations to evaluate bilateral suprarenal masses incidentally found on abdominal ultrasonographic images obtained during an annual medical health checkup. Our computed tomographic scans showed bilateral and well-circumscribed low-density suprarenal masses, while MRI revealed the tumors to be heterogeneous with low intensity on T₁-weighted images and high intensity on T₂-weighted images. A laparoscopic adrenalectomy was performed under the suspicion of a malignant tumor, such as a malignant fibrous histiocytoma. Pathologic findings indicated a retroperitoneal ancient schwannoma of two histologic types: Antoni A and Antoni B. We considered that elucidation of the characteristic features of a schwannoma would provide helpful preoperative information for diagnosis.     

含萘磺酰基N_3O_2大环化合物与DNA相互作用的光谱法研究

以8,1 1,14-三氮杂-5,6:16,17-二苯并-1,4-二氧杂环十七烷为原料,合成了含萘磺酰基的N_3O_2大环化合物,其结构经~1H NMR,MS,元素分析等表征.通过紫外光谱法和荧光光谱法研究了N_3O_2大环化合物与小牛胸腺DNA的作用机制.结果表明:N_3O_2大环化合物通过嵌插方式与DNA结合,结合常数为K_(298.2 K)~■=20706.9 dm~3·mol~(-1),K_(308.2 K)~■=12416.9 dm~3·mol~(-1),二者结合为焓驱动反应.     

Colored supramolecular charge-transfer host system using 10,10′-dihydroxy-9,9′-biphenanthryl and 2,5-disubstituted-1,4-benzoquinone

A colored charge-transfer (CT) host complex is formed using racemic (rac)-10,10′-dihydroxy-9,9′-biphenanthryl, which has a large and widely π-conjugated phenanthrene ring, as the electron donor and 2,5-disubstituted-1,4-benzoquinone as the electron acceptor. This CT host complex can include aromatic molecules as guests and its color and diffuse reflectance spectra (DRS) change according to the type of guest molecules included. Characteristically, it is possible to tune the color and DRS of the inclusion CT complex by changing the type of the component 2,5-disubstituted-1,4-benzoquinone.     

一种合成共轭高分子——聚（N,N—二甲基苯胺）的新方法

利用一种新的合成方法，首次合成了侧链带有强推生基力的聚苯衍生物－－聚（Ｎ，Ｎ－二甲基苯胺），初步研究了中间产物的形成及这种固相聚合反应的适宜条件，并通过元素分析、红外、ＨＮＭＲ及紫外光谱对聚合产物进行了结构表征。     

2,7-二乙烯吡啶基-9,9''''-二乙基芴纳米颗粒的粒度测量及荧光光谱的研究

利用二次沉淀法制备出不同粒径(101.6～516.9 nm)的2,7-二乙烯吡啶基-9,9'-二乙基芴有机纳米微粒.通过激光粒度仪测试发现:其平均粒度和多分散指数(PDI)值随着放置时间的增长、有机分子浓度的增大而增加;随放置温度的升高、表面活性剂的加入而减小.利用荧光光谱仪测试2,7-二乙烯吡啶基-9,9'-二乙基芴的氮甲基吡咯烷酮(NMP)溶液和2,7-二乙烯吡啶基-9,9'-二乙基芴纳米微粒体系的荧光激发和发射光谱,发现纳米微粒体系的荧光激发光谱和发射光谱分别在403、530 nm附近出现新的电荷转移(CT)峰.     

Interaction of nicotine with π and σ electron acceptors

Interaction of nicotine with tetracyanoethylene and iodine was investigated spectrophotometrically and found to form strong CT complexes (n−π and n-σ^*, respectively). The donor site involved in CT interaction is the pyrrolidine nitrogen. The nicotine-I₂ complex exists as the ionic structure (nicotine) I⁺-I ₃ ⁻ . Formation constants of the CT complexes in various solvents were determined from 10 to 25°C and are discussed in terms of the nature of the electron acceptor and solvent polarity. Solid CT complexes were synthesized and were characterized by microchemical analysis and infrared spectra techniques.     

钌(Ⅱ)多吡啶配合物与DNA相互作用的等温滴定量热研究(英)

The interaction of ruthenium(Ⅱ) polypyridyl complex with DNA has been studied by isothermal titration calorimetry (ITC). The results show that complex [Ru(phen)₂PMIP]²⁺ {phen=1,10-phenanthroline, PMIP=2-(4-methylphenyl)imidazo[4,5-f]1,10-phenanthroline} interacts with calf thymus DNA (CT DNA) in terms of a model for a single set of identical sites through intercalation. The results are in agreement with our previous observations from spectroscopic methods and viscosity measurements. In addition, the results further show that the driving force for DNA binding with the complex is mainly driven by the enthalpy changes, and the contribution from the entropy changes to this driving force is negligible.     

Degradation of poly(N-vinylcarbazole) by annealing under iodine pressure

After room temperature doping of poly(N-vinylcarbazole) by iodine, the powders are annealed at different temperatures (370, 470, and 570 K) for 24 h under vacuum or under iodine pressure. The obtained powders were studied by infrared absorption, x-ray photoelectron spectroscopy, x-ray diffraction, and nuclear magnetic resonance. Annealing of pure PVK powder increases the crystallization quality of the sample. Annealing with iodine induces progressive polymer degradation. At 570 K under iodine pressure the PVK is totally destroyed. The aromatic rings and the C(SINGLEBOND)N bonds have disappeared. NH₄I crystallites have formed, embeded in a degraded, cross-linked polymer matrix. © 1996 John Wiley & Sons, Inc.     

一种新的二维CT扫描方式及其重建算法

介绍了一种二维CT扫描方式及其重建算法。它是一种利用近轴X光线,针对大型回转试件的二维CT检测方法。被扫描试件依次绕与探测器平行的多个旋转中心各旋转一周。在旋转过程中,射线源在周向均布的多个角位置发射射线,同时探测器接收射线并记录投影数据。同传统的二代CT相比,对一个具体例子的计算表明,它可以节约3/4的扫描时间。计算机仿真表明了这种扫描方式和重建算法的可行性。