Two Nickel(II) Coordination Polymers Based on Tri(p‐carboxyphenyl) phosphane Oxide with Highly Selectively and Sensitively Detection of Acetone

Two nickel(II) coordination polymers, namely, {[Ni_1/2(TPO)_1/3(bib)_1/2(H₂O)] · H₂O}_n ( 1 ), and [Ni(HTPO)(bpy)(H₂O)₂]_n ( 2 ), were assembled from tripodal ligand of tripodal tri(p‐carboxyphenyl) phosphane oxide (H₃TPO) and two N‐donors [bib = 1,4‐bis(imidazolyl)benzene, and bpy = 4,4′‐bipyridine]. Their structures were determined by single‐crystal X‐ray diffraction analysis and further characterized by elemental analysis, IR spectra, powder X‐ray diffraction (PXRD), and thermogravimetric analysis (TGA). Structural analysis reveals that complex 1 is an interestingly 3D (3,4)‐connected {10³}₂{10⁶}₃ net, whereas complex 2 is a 1D polymeric chain, which was further expanded into a 3D supramolecular structure through hydrogen bonds. Luminescent sensing measurements show two nickel CPs can selectively and sensitively detect for acetone from normal solvents (DMF, DMA, DMSO, MeOH, EtOH, CH₃CN, H₂O, and N‐butanol).     

Bilayer Cylindrical Conduit Consisting of Electrospun Polycaprolactone Nanofibers and DSC Cross‐Linked Sodium Alginate Hydrogel to Bridge Peripheral Nerve Gaps

Herein, a bilayer cylindrical conduit (P‐CA) is presented consisting of electrospun polycaprolactone (PCL) nanofibers and sodium alginate hydrogel covalently cross‐linked with N,N′‐disuccinimidyl carbonate (DSC). The bilayer P‐CA conduit is developed by combining the electrospinning and outer–inner layer methods. Using DSC, as a covalent crosslinker, increases the degradation time of the sodium alginate hydrogel up to 2 months. The swelling ratio of the hydrogel is also 503% during the first 8 h. The DSC cross‐linked sodium alginate in the inner layer of the conduit promotes the adhesion and proliferation of nerve cells, while the electrospun PCL nanofibers in the outer layer provide maximum tensile strength of the conduit during surgery. P‐CA conduit promotes the migration of Schwann cells along the axon in a rat model based on functional and histological evidences. In conclusion, P‐CA conduit will be a promising construct for repairing sciatic nerves in a rat model.     

Contributions to the Optimization of a Caprolactam Production Plant by Radiotracer Techniques

Residence time spectra and material distributions in an operating caprolactam production plant were measured by means of sodium 24, bromine 82 and technetium 99m. The results of the tracerexperiments contributed to an optimization of the plant.     

Synthesis of pyrano[2,3‐c]pyrazole derivatives using Fe3O4@SiO2@piperidinium benzene‐1,3‐disulfonate (Fe3O4@SiO2 nanoparticle‐supported IL) as a novel,green and heterogeneous catalyst

A simple, green and efficient protocol for the one‐pot four‐component synthesis of pyrano[2,3‐c ]pyrazole derivatives produced from reaction between aryl aldehydes, ethyl acetoacetate, malononitrile and hydrazine hydrate in the presence of nano magnetic piperidinium benzene‐1,3‐disulfonate was synthesized in water at 60 °C. The Fe₃O₄@SiO₂ nanoparticle‐supported IL was designed and synthesized. The present process offers advantages such as clean reaction, short reaction time, good to excellent yield, easy purification and easy recoverable catalyst.     

Analysis of toldimfos in porcine muscle and bovine milk using liquid chromatography–triple quadrupole mass spectrometry

An analytical method was developed for the detection of toldimfos sodium residues in porcine muscle and bovine milk using liquid chromatography–triple quadrupole tandem mass spectrometry (LC–MS/MS) analysis. The drug was extracted from muscle and milk using 10 mm ammonium formate in acetonitrile and then purified using n ‐hexane. The drug was well separated on a Luna C₁₈ column using a mixture of 10 mm ammonium formate in ultrapure water (A) and acetonitrile (B) as the mobile phase. Good linearity was achieved over the tested concentration range (0.005–0.03 mg/kg) in matrix‐matched standard calibration. The determination coefficients (R ² ) were 0.9942 and 0.9898 for muscle and milk, respectively. Fortified porcine muscle and bovine milk contained concentrations equivalent to and twice the limit of quantification (0.005 mg/kg) yielded recoveries in the range of 75.58–89.74% and relative standard deviations of ≤8.87%. Samples collected from large markets located in Seoul, Republic of Korea, tested negative for toldimfos sodium residue. In conclusion, ammonium formate in acetonitrile can effectively extract toldimfos sodium from porcine muscle and bovine milk without solid‐phase extraction, which is usually required for cleanup before analysis. This method can be applied for the routine analysis of toldimfos in foods of animal origins.     

Complexation Based Voltammetric Determination of Pantoprazole Sodium in Pharmaceutical Formulations and Rabbit Plasma

Square wave adsorptive stripping voltammetric (SQWASV) method has been utilized to confirm and elucidate the possible complexation reaction between pantoprazole sodium and cobalt as a transition metal in Britton‐Robinson buffer (pH=7.0). The current signal due to the oxidation process was a function of the amount of pantoprazole sodium, pH of the medium, cobalt concentration and accumulation time at the electrode surface. The oxidation peak current has varied linearly with the concentration over the range of 0.1–9.0 nM. The limit of detection was found to be 0.04 nM. The validity of the method was successfully applied for the determination of pantoprazole sodium in pharmaceutical formulations with a pharmacokinetic study in rabbit plasma. The simplicity, rapidity, sensitivity and selectivity of this method make it a very attractive alternative to the other existing methods in the quality control laboratories.     

Ein Vergleich zwischen radioaktiver Markierung und Indikator-Aktivierungsanalyse bei der Messung von Verweilzeitspektren

An VK-Z-Rohren zur Herstellung von Polyamid wurden Verweilzeitspektren mit der Methode der radioaktiven Markierung und der Methode der Indikatoraktivierungsanalyse gemessen. Die nach den beiden Methoden ermittelten Verweilzeitspektren werden miteinander verglichen. Die Übereinstimmung der Verweilzeitspektren wird durch Gegenüberstellung der statistischen Momente und durch einen Test nach Kolmogoroff-Smirnov geprüft. Es wird der experimentelle Aufwand beider Verfahren diskutiert und eine Fehlerabschätzung durchgeführt.     

Chemoselective Esterification of Phenolic Acids in the Presence of Sodium Bicarbonate in Ionic Liquids

Chemoselective esterification of phenolic acids with dialkyl sulphates or alkyl halides in the presence of sodium bicarbonate in 1,3‐dialkylimidazolium ionic liquids is reported in excellent yields and less reaction time as compared to organic solvents.     

One-step synthesis ofα,β-unsaturated arylsulfones by a novel multicomponent reaction of aromatic aldehydes,chloroacetonitrile, benzenesulfinic acid sodium salt

A new and green method for the synthesis of α,β-unsaturated arylsulfones had been achieved through the condensation of aromatic aldehydes,chloroacetonitrile,benzenesulfinic acid sodium salt in the presence of l-butyl-3-methyl imidazolium hydroxide([bmim]OH) in EtOH under reflux.The ionic liquid was recovered and recycled for subsequent reactions.The advantages of this protocol were non-toxic,easy work-up and good yields.     

Preparation and characterization of vanadium(IV) oxide supported on SBA-15 and its catalytic performance in benzene hydroxylation to phenol using molecular oxygen

Preparation of dispersed transition metal oxides catalyst with low oxidation state still remains a challenging task in heterogeneous catalysis.In this study,vanadium oxides supported on zeolite SBA-15 have been prepared under hydrothermal condition using V 2 O 5 and oxalic acid as sources of vanadium and reductant,respectively.The structures of samples,especially the oxidation state of vanadium,and the surface distribution of vanadium oxide species,have been thoroughly characterized using various techniques,including N 2-physisorption,X-ray diffraction(XRD),transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS),UV-visible spectra(UV-Vis) and UV-visible-near infrared spectra(UV-Vis-NIR).It is found that the majority of supported vanadium was in the form of vanadium(IV) oxide species with the low valence of vanadium.By adjusting hydrothermal treatment time,the surface distribution of vanadium(IV) oxide species can be tuned from vanadium(IV) oxide cluster to crystallites.These materials have been tested in the hydroxylation of benzene to phenol in liquid-phase with molecular oxygen in the absence of reductant.The catalyst exhibits high selectivity for phenol(61%) at benzene conversion of 4.6%,which is a relatively good result in comparison with other studies employing molecular oxygen as the oxidant.