Potentialfeld- und Kraftkonstanten voncis- undtrans-Difluordiazin

Zusammenfassung Ancis-Difluordiazin planarer Konfiguration mit C_2v-Symmetrie und antrans-Difluordiazin planarer Konfiguration mit zentrosymmetrischer Struktur mit C_2h-Symmetrie wurde eine Schwingungs- und Strukturanalyse unter Verwendung eines modifizierten Valenzkraftfeldes mit sechs Kraftkonstanten ausgeführt. Die Berechnung der Kraftkonstanten erfolgte nach gruppentheoretischen Methoden auf der Grundlage der Ergebnisse neuerer Struktur- und verfeinerter Schwingungsanalysen. Die Ergebnisse werden mit den an Molekülen mit ähnlichen chemischen Bindungen und angenähert identischen Kernabständen erhobenen verglichen.

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Potential field and force constants of cis- and trans-difluorodiazines

Vibrational and structural analysis ofcis-difluorodiazine possessing a planar configuration with C_2v symmetry and oftrans-difluorodiazine possessing a planar configuration of centrosymmetrical structure with C_2h symmetry has briefly been made. A modified six-force constant valence force field has been employed and the force constants have been evaluated from the recent structural and refined vibrational data for bothcis- andtrans-difluorodiazines by the group theoretical method. A brief discussion of the results has been made in relation to other molecules having similar chemical bonds with nearly identical internuclear distances.

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Mit 2 Abbildungen     

Highly regio- and chemoselective [2 + 2 + 2] cycloaddition of 1,6-heptadiynes with allenes catalyzed by cobalt complexes

The CoI2(PPh3)2/Zn system effectively catalyzes the [2 + 2 + 2] ene-diyne cycloaddition of 1,6-heptadiynes with allenes in a highly regio- and chemoselective fashion to yield substituted benzene derivatives in good to excellent yields.     

Electrochemical mass spectroscopic and surface photovoltage studies of catalytic water photooxidation by undoped and carbon-doped titania

Carbon-doped TiO2, demonstrated as an efficient photocatalyst in visible light photooxidation of organic compounds, was prepared with different doping concentrations and investigated via differential electrochemical mass spectroscopy (DEMS) and capacitive surface photovoltage (SPV) measurements in the form of thin layer electrodes. In all cases the total photocurrent as well as the surface photovoltage of the doped materials decreased markedly in relation to the undoped one. No detectable oxygen evolved from the doped electrodes in acidic solution under UV-light excitation. Since an oxidation of formic acid is still apparent, it is concluded that this oxidation occurs via isolated, catalytically poorly active trap states within the forbidden energy region. The existence of these states is confirmed by capacitive SPV measurements.     

Microwave-assisted iridium-catalyzed [2+2+2] cycloaddition of resin-bound dipropargylamine with alkynes

The [Ir(COD)Cl]₂/dppe system effectively catalyzes the solid-phase [2+2+2] cycloaddition of resin-bound dipropargylamine with alkynes under microwave conditions. The reaction results in high purity of isoindoline derivatives with moderate yields.     

Epilogue to the Gerald Maggiora Festschrift: a tribute to an exemplary mentor,colleague, collaborator,and innovator

Journal of Computer-Aided Molecular Design - In May 2022, JCAMD published a Special Issue in honor of Gerald (Gerry) Maggiora, whose scientific leadership over many decades advanced the fields of...     

Synthesis of spiropyrazoline [5.3′] 4′-chromanones

Synthesis of a series of novel 1,3-diphenyl-4-aryl spiropyrazolines [5.3′] 4′-chromanones has been accomplished in good yields by regioselective 1,3-dipolar cycloaddition of diphenylnitrilimine to 3-arylidene-4-chromanones. X-ray crystal structure analysis of one of the products 4a confirms the structure and the regiochemistry of cycloaddition. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:327–332, 1998     

Derivation,Functionalization of (S)-Goniothalamin from Goniothalamus wightii and Their Derivative Targets SARS-CoV-2 MPro,SPro, and RdRp: A Pharmacological Perspective

The tracing of an alternative drug, Phytochemicals is a promising approach to the viral threats that have emerged over the past two years. Across the world, herbal medicine is a better solution against anti-viral diseases during pandemic periods. Goniothalamus wightii is an herbal plant, which has diverse bioactive compounds with anticancer, antioxidant, and anti-viral properties. The aim of the study was to isolate the compound by chromatography studies and functionalization by FT-IR, LC-MS, and NMR (C-NMR, H-NMR). As a result, the current work focuses on whether (S)-Goniathalamin and its analogue could act as natural anti-viral molecules for multiple target proteins viz., M^Pro, RdRp, and S^Pro, which are required for SARS-CoV-2 infection. Overall, 954 compounds were examined and the molecular-docking studies were performed on the maestro platform of Schrodinger software. Molecular-dynamics simulation studies were performed on two complex major compounds to confirm their affinity across 150 simulations. This research suggests that plant-based drugs have high levels of antiviral properties against coronavirus. However, more research is needed to verify its antiviral properties.     

Distribution of radioactive citrinin in tissues and serum protein(s)+

A brief report on the food pollutant-mycotoxin, citrinin, is presented. Radioactive¹⁴C-citrinin was isolated from Aspergillus candidus grown culture supplemented with¹⁴C-glucose. Quick uptake of¹⁴C-citrinin was observed in the liver and kidney of mice, after the administration of a single dose. In vitro studies with¹⁴C-citrinin reveal that it gets bound to the albumin fraction of human serum. Part of Ph. D. Thesis submitted to the University of Madras in 1973.     

Analytical studies of gain optimization in CO2-N2 gasdynamic lasers employing two-dimensional wedge nozzles

An analytical method has been proposed to optimise the small-signaloptical gain of CO₂-N₂ gasdynamic lasers (gdl) employing two-dimensional (2D) wedge nozzles. Following our earlier work the equations governing the steady, inviscid, quasi-one-dimensional flow in the wedge nozzle of thegdl are reduced to a universal form so that their solutions depend on a single unifying parameter. These equations are solved numerically to obtain similar solutions for the various flow quantities, which variables are subsequently used to optimize the small-signal-gain. The corresponding optimum values like reservoir pressure and temperature and 2D nozzle area ratio also have been predicted and graphed for a wide range of laser gas compositions, with either H₂O or He as the catalyst. A large number of graphs are presented which may be used to obtain the optimum values of small signal gain for a wide range of laser compositions without further computations.     

Synthesis of (+ or -) thalicmine (ocoteine)

The structure of the alkaloid thalicmine has been proved to be 1,2-methylenedioxy-3,9,10-trimethoxyaporphine by a synthesis of the racemic form of the alkaloid on classical lines.