One-pot synthesis of highly functionalized pyrano[2,3-c]pyrazole-4,4′-diacetate and 6-oxo-pyrano[2,3-c]pyrazole derivatives catalyzed by urea

A facile one-pot, multicomponent protocol for the synthesis of 1,4-dihydro-pyrano[2,3-c]pyrazole derivatives using a urea catalyst is reported. This transformation proceeds via a four-component reaction of ethyl acetoacetate, a hydrazine, 3-oxo-pentanedioic acid dimethyl ester, and malononitrile. The bifunctional nature of urea means that it catalyzes many steps in this transformation, including domino Knoevenagel condensation, Michael addition, and ring opening and closing reactions. This synthetic method has several advantages, including good yield, simple work-up, harmless by-products, and simple purification.     

Differentiation of Borrelia burgdorferi sensu lato species by temperature gradient gel electrophoresis

Borrelia burgdorferi sensu lato is a multispecies complex of pathogenic spirochetes, causing Lyme borreliosis. Due to clinical, epidemiological, and taxonomical implications, there is a need for identification of isolated Borrelia strains. In the present study, we have optimized TGGE for B. burgdorferi sensu lato species differentiation and the results were compared with two reference methods, namely PFGE and restriction of 5S-23S intergenic space region PCR product. A differentiation of B. garinii, B. afzelii, and B. burgdorferi senso stricto species with TGGE was possible and intraspecies variation was detected. Results compared between TGGE, PFGE, and restriction of 5S-23S intergenic space region PCR product showed no difference in specificity of species identification.     

乌鲁木齐市医疗垃圾产生量初步研究

为了解乌鲁木齐市医疗垃圾处理现状,并为制定相应的对策提供依据,作者通过对乌鲁木齐市不同规模、不同性质的26所医院进行了医疗垃圾处理相关情况的调查发现：（1）各医院对医疗垃圾处理的重视程度普通有所提高,但不同性质、规模的医院之间存在差异;（2）大型综合性医院、中型综合性医院、小型综合性医院、企业职工医院、专科医院平均每床日产生医疗垃圾量分别为0．55kg,0．60kg,0．53kg,0．55kg,0．65kg;不同性质、规模的医院平均每日产生的医疗垃圾量有显著性差异,但每日每床产生的医疗垃圾量没有显著差异;（3）医院每日产生的医疗垃圾量与医院病床数、病床使用率有密切相关关系;（4）不同性质、规模的医院对医疗垃圾的收集、储存和处理方式有显著差异．针对调查中发现的在医用垃圾管理、收集、储存、运输、处理方面存在的问题提出了建议．     

Deoxygenative Arylation of Carboxylic Acids by Aryl Migration

An unprecedented deoxygenative arylation of aromatic carboxylic acids has been achieved, allowing the construction of an enhanced library of unsymmetrical diaryl ketones. The synergistic photoredox catalysis and phosphoranyl radical chemistry allows for precise cleavage of a stronger C−O bond and formation of a weaker C−C bond by 1,5-aryl migration under mild reaction conditions. This new protocol is independent of substrate redox-potential, electronic, and substituent effects. It affords a general and promising access to 60 examples of synthetically versatile o-amino and o-hydroxy diaryl ketones under redox-neutral conditions. Furthermore, it also brings one concise route to the total synthesis of quinolone alkaloid, (±)-yaequinolone A2, and a viridicatin derivative in satisfying yields.     

O2 and CO binding to tetraaza-tripodal-capped iron(II) porphyrins

A series of tris(2-aminoethylamine) (tren) capped iron(II) porphyrins has been synthesized and characterized and their affinities for dioxygen and carbon monoxide measured. The X-ray structure of the basic scaffold with nickel inserted in the porphyrin is also reported. All the ligands differ by the nature of the group(s) attached to the secondary amine functions of the cap. These various substitutions were introduced to probe if a hydrogen bond with these secondary amine groups acting as the donor could rationalize the high affinity of these myoglobin models. This work clearly indicates that the cage structure of the tren predominates over all the other appended groups with the exception of p-nitrophenol.     

Efficient and versatile synthesis of new porphyrins bearing an N3O moiety: ligands for mimicking cytochrome c oxidase

Two new generations of ligands for cytochrome c oxidase mimicking have been designed and synthesized via an efficient, convergent, and versatile synthesis. These porphyrins are functionalized with both an internal nitrogen base on one side and a triaza (N3) or a triaza-phenol (N3O) moiety on the other side, attached to the macrocycle by various spacers. Unlike tailed porphyrins, the triaza motif as well as the nitrogen base are linked by two points.     

Structural Evolution of an Organic Semiconducting Molecule onto a Soft Substrate

The structural organization and evolution of the organic semiconducting molecule 2,7‐dioctyloxy[1]benzothieno[3,2‐b]‐benzothiophene on a soft matrix is studied. Thin films of a blend formed from polystyrene and the molecule were prepared by spin‐coating onto silicon substrates, which were subsequently studied by using a combination of microscopy and scattering techniques. The organic semiconducting molecule segregated to the surface and developed a phase with a different structure to the bulk, as in the case of a substrate induced phase observed previously. Under a solvent vapor annealing procedure, the growth of micrometer‐sized tetragonal crystals onto the polymer surface was observed, which was not evidenced for the silicon substrates.     

Investigation of the Qx–Qy Equilibrium in a Metal‐Free Phthalocyanine

Phthalocyanines (Pcs) have attracted a lot of interest as small molecules for organic electronics. However, some excited‐state properties of metal‐free phthalocyanines, as for example, the dynamics of the transition between the nondegenerate Q_x and Q_y states in a metal‐free phthalocyanine, have not been fully established. This effect results in a blue‐shifted shoulder with low intensity in the Pc fluorescence spectrum. This shoulder was suggested to be related to emission from the more energetic Q_y state. By using ultrafast femtosecond transient absorption, we have found a clear equilibrium between the Q_x and Q_y state of metal‐free phthalocyanines in solution.     

An expeditious synthesis of tailed tren-capped porphyrins

[structure: see text] A one-pot two-step versatile synthesis of tailed tren-capped porphyrins has been achieved. The two resulting ligands demonstrate that this expeditious method can be applied to various axial bases to obtain highly functionalized macromolecules attractive for heme modeling purposes. Dioxygen binding of the pyridine-tailed iron complex is reported as a direct application.     

Substrate-induced phases: transition from a liquid-crystalline to a plastic crystalline phase via nucleation initiated by the substrate

The presence of substrate-induced phases in thin films is an intriguing phenomenon with the physical and chemical factors responsible for their formation are not yet clearly understood. In this article, we present the structure and morphological changes associated with a substrate-induced phase in a discotic liquid crystal. The thin films of the discotic molecule are characterised by a combination of various X-ray diffraction methods to investigate the structural properties. Atomic force microscopy and polarised optical microscopy are used to determine the thin film morphologies. This is the first experimental proof of the presence of a substrate-induced phase in discotic liquid crystal, although they are known in thin films of molecular crystals. Moreover, we sought to decipher how the substrate-induced phase behaves with the evolution of time, temperature and changes at the interfaces. This work gives a unique example where the two-dimensional liquid-crystalline phase converts to a three-dimensional crystal plastic phase because of nucleation caused by the solid substrate over a time scale of a month or longer.