Studien über Adsorption. VIII

Ohne Zusammenfassung Deutsch von Luise Pieper (Sobernheim, Rhl.)     

Sensitive,Selective, Precise and Accurate LC–MS Method for Determination of Clonidine in Human Plasma

A selective and sensitive liquid chromatography–mass spectrometric method in ESI (+ve) mode was developed and validated completely in human plasma. Clonidine and IS, carbamazapine, were extracted from human plasma via liquid–liquid extraction with ethyl acetate. Following evaporation under nitrogen, the residue was reconstituted with mobile phase and analyzed using API 4000 LC–MS–MS system. An isocratic program with binary mobile phases (0.1% formic acid in water and acetonitrile) was used to separate interference peaks by a C18 analytical column. Linearity range was 0.49–73.98 ng mL⁻¹. The intra- and inter-day accuracy and precision were within acceptable limits (≤15%). This method was successfully applied to a single dose 25 μg tablets BE study of clonidine in healthy male volunteers.

     

Chromatographische Analyse

Ohne Zusammenfassung     

Selective functionalization of ferrocenyl compounds using a novel solvent free synthetic method for the preparation of bioactive unsymmetrical ferrocenyl derivatives

A novel solvent free synthetic method has been designed by using rice husk ash (RHA) as solid support for the selective functionalization of ferrocenyl derivatives and described the synthesis of a 1,1′‐unsymmetrically bi‐functionalized ferrocenyl compounds for their biological evaluation. Single crystal X‐ray structural evaluation showed some interesting intra‐molecular hydrogen bonding interactions across the chains of the ferrocenyl molecule, while DFT calculation revealed the significance of the orientation between the two cyclopentadienyl rings for the hydrogen bonding interaction. Redox and antibacterial properties have been studied to understand the electronic and biological effect of different hydrazone system and their potential for future application.     

Correction to: A literature review on police patrolling problems

Annals of Operations Research -     

Ene-Reductase: A Multifaceted Biocatalyst in Organic Synthesis

Biocatalysis integrate microbiologists, enzymologists, and organic chemists to access the repertoire of pharmaceutical and agrochemicals with high chemoselectivity, regioselectivity, and enantioselectivity. The saturation of carbon-carbon double bonds by biocatalysts challenges the conventional chemical methodology as it bypasses the use of precious metals (in combination with chiral ligands and molecular hydrogen) or organocatalysts. In this line, Ene-reductases (ERs) from the Old Yellow Enzymes (OYEs) family are found to be a prominent asymmetric biocatalyst that is increasingly used in academia and industries towards unparalleled stereoselective trans-hydrogenations of activated C=C bonds. ERs gained prominence as they were used as individual catalysts, multi-enzyme cascades, and in conjugation with chemical reagents (chemoenzymatic approach). Besides, ERs’ participation in the photoelectrochemical and radical-mediated process helps to unlock many scopes outside traditional biocatalysis. These up-and-coming methodologies entice the enzymologists and chemists to explore, expand and harness the chemistries displayed by ERs for industrial settings. Herein, we reviewed the last five year's exploration of organic transformations using ERs.     

Ultrafast Charge Delocalization Dynamics of Ambient Stable CsPbBr3 Nanocrystals Encapsulated in Polystyrene Fiber

CsPbBr₃ nanocrystals (NCs) encapsulated in a transparent polystyrene (PS) fiber matrix (CsPbBr₃@PS) have been synthesized to protect the NCs. The ultrafast charge delocalization dynamics of the embedded NCs have been demonstrated, and the results are compared with the pristine CsPbBr₃ in toluene. The electrospinning method was employed for the preparation of CsPbBr₃@PS fibers by using a polystyrene solution doped with pre-synthesized CsPbBr₃ and characterized by XRD, HRTEM, and X-ray photoelectron spectroscopy (XPS). Energy level diagrams of CsPbBr₃ and PS suggest that CsPbBr₃@PS fibers make a type I core–shell structure. The carrier cooling for CsPbBr₃@PS fibers is found to be much slower than pure CsPbBr₃ NCs. This observation suggests that photoexcited electrons from CsPbBr₃ NCs get delocalized from the conduction band of the perovskite to lowest unoccupied molecular orbital (LUMO) of the PS fiber matrix. The CsPbBr₃@PS fibers possess remarkable stability under ambient conditions as well as in water over months. The clear understanding of charge carrier relaxation dynamics of CsPbBr₃ confined in PS fibers could help to design robust optoelectronic devices.     

Preferential Face‐on and Edge‐on Orientation of Thiophene Oligomers by Rational Molecular Design

Precise control over the supramolecular organization of organic semiconducting materials guiding to exclusive face‐on or edge‐on orientation is a challenging task. In the present work, we study the preferential packing of thiophene oligomers induced through rational molecular designing and self‐assembly. The acceptor–donor–acceptor‐type oligomers having 2‐(1,1‐dicyano‐methylene)rhodanine as acceptor ( OT1 ) favored a face‐on packing, whereas that of functionalized with N‐octyl rhodanine ( OT2 ) preferred an edge‐on packing as evident from 2D‐grazing incidence angle X‐ray diffraction, tapping‐mode atomic force microscopy (AFM) and Raman spectroscopy analyses. The oligomers exhibited anisotropic conductivity in the self‐assembled state as an outcome of the preferred orientation, revealed by the conducting AFM experiment.