Copolymerization of butadiene and styrene by initiation with alkyllithium and alkali metal tert-butoxides

Combinations of the various alkali metal tert-butoxides with organolithium initiators give homogeneous copolymers of butadiene and styrene. The unprecedented flexibility of this initiator system allowed preparation of random copolymers with various amounts of vinyl unsaturation and various degrees of randomness. The butyllithium–potassium tert-butoxide initiator system was more efficient than phenylpotassium.     

Adsorption and interface accumulation of aquasol and organosol carbon particles labeled with99mTc

Aerosol particles of^99mTc-labeled carbon were prepared by sublimation and introduced in various liquid media. The adsorption of the aquasol and organosol particles were studied for various adsorbing substances and media, with the effect of surface treatment and voltage application. The particles often accumulated at the aqueous-organic interface, and also on the vessel surface in the presence of both aqueous and organic phases. The distribution of the particles was examined by a gamma-camera for different organic phases under various concentrations of electrolytes in the aqueous phase.     

Models of supramolecular structure and properties of cellulose

Various models of cellulose supramolecular organization, such as the models of crystalline micelles, defective crystals, amorphous stacks, folded fibrils, fringed fibrils, crystalline fibrils with the amorphous surface, and various variants of the model of amorphous–crystalline fibrils with straightened chains have been critically analyzed. Specific features, advantages, and drawbacks of various models have been examined. The main methods for the structural studies of cellulose have been discussed. A model of mesomorphous- crystalline fibrils with straightened chains and the paracrystalline surface layer has been advanced, and it has been shown that this model may be used to forecast various properties of cellulose.     

Azinyl derivatives of ferrocene and cymantrene. Synthesis and properties

In the present review comparative data concerning various synthetic approaches and methodologies used in the series of ferrocene and cymantrene derivatives to create various materials, namely, catalytic systems, sensory and other molecular devices, polymers as well as physiologically active substances, for the period from 2000 till 2016 are given. Aspects of practical application of the above compounds are also considered.     

Classical and knudsen thermogravimetry to check states and displacements of water in food systems

Water states and displacements can be investigated with thermogravimetry (TG) either in its classical or in the Knudsen version (where standard pans are replaced with Knudsen cells). The case of wheat flour dough is considered in various steps of bread making, namely, mixing, proofing, baking, staling. The split of DTG signals into various components (gaussian functions) support the assumption that the overall dough water is partitioned into various fractions. Few comments are devoted to water displacements during freezing.This revised version was published online in November 2005 with corrections to the Cover Date.     

Kinetics and reaction mechanisms of diazo compounds and iodonium salts as studied by chemically induced dynamic nuclear polarisation

CIDNP phenomena in various reactions of diazo compounds and iodonium salts are described. The various reaction pathways leading to the formation of polarised aromatic products are analysed in detail.     

Competition between solvent quenching and indole quenching of 9-fluorenone: A spectroscopic and computational study

The interaction between 9-fluorenone, various indoles and solvents has been studied using steady-state fluorescence spectroscopy and quantum chemical calculations. It was determined that polar protic solvents such as methanol and ethanol significantly quenched the fluorescence of 9-fluorenone but various indoles reversed the solvent quenching. The effect of various solvents on the 9-fluorenone carbonyl vibration was investigated using infrared spectroscopy. Ab initio calculations using Gaussian03 were also carried out in order to determine the minimum energy conformations of these systems along with binding energies.     

Structure and features of thermal oxidation of carbon nanostructured materials

The process of the thermal oxidation in air of various carbon materials used as a catalyst support and a component of fuel cell catalytic layers was studied by differential thermal analysis. The structural characteristics of carbon materials of various classes were compared using data of the adsorption-structure and differential thermal analyses.     

NMR study of some coumarins and furocoumarins methylated

The ¹H and ¹³C NMR spectra of various methylcoumarins and methylfurocoumarins are reported. All signals were assigned and the influence on chemical shifts of methylation at various positions was determined.     

六味地黄丸的精细指纹图谱分析及模式识别分类研究

采用高效液相色谱建立了六味地黄丸的指纹图谱,对两个厂家的16批产品进行了测定,并结合中药相似度软件和主成分分析法对全指纹图谱和其精细指纹图谱进行了模式识别研究。结果表明,中药相似度软件能够对不同厂家的产品进行区分但也可能造成误判;在主成分分析法的投影图中,两个厂家的产品明显聚为两类,而且不同批次产品的差异也能够显示出来。     

Investigation of various synthetic protocols for self-assembled nanomaterials and their role in catalysis: progress and perspectives

Self-assembly is one of the most used strategies in the controlled synthesis and design of well-organized nanomaterials for various applications in diverse realms namely catalysis, sensors, microelectronics, energy storage, and energy conversion. It is quite common to see reports on the synthesis and design of several self-assembled nanomaterials for the application in the catalysis of various chemical, photochemical, and electrochemical reactions and processes. Nevertheless, a combined overview on the synthetic strategies for self-assembled nanomaterials has not been reported in any form in literature. Owing to the current interest shown and the future significance on the self-assembled nanomaterials, it is highly essential to have such an elaborated review on the progress and perspectives of synthesis of self-assembled nanomaterials and their subsequent application to catalysis of various chemical, photochemical, and electrochemical reactions and processes. In this review, we have highlighted various synthetic methodologies used so far for fabricating the self-assembled nanomaterials that includes Langmuir–Blodgett method, layer-by-layer assembly, amphiphilic (artificial and bio) self-assembly, and template-free approach. Nanomaterials derived from the above mentioned methods in various catalysis reactions are also highlighted in detail with an emphasis on confronts and prospects in the field of materials self-assembling and its concomitant application to catalysis.     

Efficient and Straightforward Synthesis of Tetrahydrocarbazoles and 2,3-Dimethyl Indoles Catalyzed by CAN

A simple protocol was established to synthesize 2,3-dialkyl indoles and various tetrahydrocarbazoles via Fischer indole synthesis. This method uses ceric ammonium nitrate as a catalyst for the Fischer indole synthesis with substituted phenyl hydrazine hydrochlorides and 2-butanone, phenyl propanal, and cyclohexanone. This process is a practical synthetic method for the preparation of various 2,3-disubstituted alkyl indoles and tetrahydrocarbazoles.     

Relationship between the molar volume and enthalpy of formation, polarizability, and ionization potential of CHNO-containing organic substances

A new approach to revealing a relationship between various physicochemical properties of organic compounds is suggested. The basic principle of this approach consists in that deviations of experimental values of various molecular parameters from linear dependences for the constituent elements are due to intramolecular forces of the same nature.     

Synthesis and Applications of Selected Fluorine-Containing Fluorophores

The synthesis of fluorine-containing small molecules has had numerous benefits of improving the quality and efficiency of many applications of these compounds. For example, fluorine adds promising functionalities in various areas of imaging (MRI, PET, and NIR); gives cell-targeting properties; and has demonstrated improvements in cell permeability, solubility, and other pharmacologic properties. For these and other numerous reasons, fluorination of molecules has grown in popularity in various fields of chemistry. Many reports show the effects observed from increasing the number of fluorine atoms on a fluorophore scaffold. This report will cover the most significant applications and improvements that fluorine has contributed to in various dye scaffolds such as BODIPY, rhodamine, phthalocyanine, and cyanine in the recent decade.     

Synthesis and cytotoxicity study of pyrazoline derivatives of methoxy substituted naphthyl chalcones

2-Acetyl naphthalene reacts with various methoxy substituted benzaldehyde in the presence of 10 % sodium hydroxide solution giving functionalized chalcones. The synthesized chalcones when further reacted with hydrazine hydrate in the presence of acetic acid afforded N-acetyl pyrazolines. All the synthesized products were confirmed by various spectral data such as FTIR, ¹H NMR, ¹³C NMR, and HRMS studies. All the synthesized compounds were screened for cytotoxicity against various cell lines.     

Convergent synthesis of 2,3-bisarylpyrazolones through cyclization of bisacylated pyrazolidines and hydrazines

Cyclization of various bisacylated hydrazines and pyrazolidines using DBU or sodium hydride leads to the formation of various mono-, bi- and tricyclic pyrazolone scaffolds in 41-98% yield. The convergent nature by which the precyclization intermediates are constructed allows for rapid derivatization about the pyrazolone core.     

Synthesis and N-methylation of tetrabutylammonium isocyanurate

A simple and efficient method for the synthesis of ammonium salt of isocyanuric acid is set out. This process is based on the direct addition of the corresponding hydroxide to isocyanuric acid. This salt exhibits several interesting properties. Its alkylation by iodomethane in various solvents is demonstrated and leads to various substituted isocyanurate derivatives.     

A comparison of isoconversional and model-fitting approaches to kinetic parameter estimation and application predictions

A variety of isoconversional and model fitting approaches, all of which use multiple heating schedules, are used to analyze selected data from the ICTAC kinetics and lifetime projects as well as additional simulated data sets created for this work. The objective is to compare the accuracy and suitability of various approaches for various types of chemical reactions. The various simulated data sets show that model fitting and isoconversional methods have comparable reliability for extrapolation outside the range of calibration. First, there is as much variability in prediction for various isoconversional methods as there is between isoconversional methods as a group and different plausible explicit models. Of the three isoconversional models investigated, the Friedman method is usually the most accurate. This is particularly true for energetic materials that have a drop in apparent activation energy in the latter stages of reaction, which leads to a delayed onset of rapid autocatalysis at lower temperatures. It is difficult to determine a priori whether isoconversional or model fitting approaches will give more accurate predictions. The greatest reliability is attained by using both the isoconversional and model fitting approaches on a combination of isothermal and constant heating rate data.     

Structures of silylenoids and effects of metallic and haloid atoms on their stability

The structural characteristics of silylenoids, H2SiMX, where M = Li or Na and X = F or Cl, have been studied by ab initio calculations. H2SiMX can be represented as adducts of silylene H2Si with alkali metal halogenides, MX. The associative energies at different calculational levels of various structures of H2SiMX are given. Effects of metallic and haloid atoms on the stability of various structures of H2SiMX are also discussed in this paper.     

Synthesis and properties of azole-containing ionenes

High-molecular-mass compounds (ionenes) containing charged imidazole and 1,2,4-triazole rings in the main chain are synthesized via the reaction of dihaloalkanes with bis(azoles) of various structures. It is shown that azole-containing ionenes can be involved in interpolymer reactions with negatively charged polyelectrolytes (polyacrylic acid and heparin) to form soluble and insoluble polyelectrolyte complexes of various compositions. The results confirm a potentially high antiheparin activity of azole-containing ionenes.