An electrochemical method for the synthesis of silicon—silicon bonds

An electrochemical method for the preparation of compounds containing Si—Si bonds has been developed and its scope investigated.     

Simple preparative method for the synthesis of monobromocyclopropanes

Conclusions A simple method has been developed for the reduction of gem-dibromocyclopropanes to give monobromocyclopropanes by the action of a readily available nonmetallic reagent, sodium hydrosulfite, at 90–100C in a mixture of 2-propanol, water, and DMF. This method gives 75–86% yields of the desired products and the complete absence of the products of complete reduction.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2818–2820, December, 1984.Deceased.     

Effect of rate retardation in RAFT grafting polymerization from silicon wafer surface

Polystyrene and poly(butyl acrylate) were grafted from silicon wafer surface by reversible addition‐fragmentation chain transfer (RAFT) polymerization. Three RAFT agents were immobilized onto silicon wafer through their leaving/initiating groups (R group). Grafting polymerization of butyl acrylate (BA) and styrene (St) was then carried out from the immobilized RAFT agents. The immobilization of the RAFT agents and the subsequent grafting polymerization of St and BA were evaluated by ellipsometry and X‐ray photoelectron spectroscopy. It was found that type of monomer, structure of RAFT agent, and local RAFT concentration on the surface have dramatic influences on the thickness of grafted polymer layer. The grafting polymerization with more severe rate retardation effect yielded thinner polymer films on the silicon wafer. Selection of a RAFT agent with little rate retardation was critical in the grafting polymerization to achieve thick films. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 970–978, 2008     

Mechanisms of particle removal from silicon wafer surface in wet chemical cleaning process

A quantitative mechanism of particle removal from silicon wafer surfaces by a wet chemical cleaning process is proposed. The particles are removed from the surface due to the combined effects of chemical etching and a net repulsive interaction between the particle and surface. The mechanism suggests that a critical etching depth, which has been determined theoretically, and an optimal etching rate, which can be determined from etching profile calculation, are required for particle removal. The study will help in the optimization of cleaning processes and formulation of superior cleaning solutions.     

Simple method for the synthesis of 2-trichloromethyl-4-quinazolones

Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 698–699, May, 1991.     

Simple method for the synthesis of bicyclic pyridine bases from 1-ethynylcycloalkanols and carboxylic acid chlorides

Conclusions A new, simple and effective method was developed for the synthesis of difficultly obtainable bicyclic pyridine bases by the condensation of cyclic ethynylcarbinols with carboxylic acid anhydrides in the presence of an equimolar ZnCl₂-POCl₃ mixture followed by treatment with ammonium hydroxide.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2604–2607, November, 1988.     

Physical vapor deposition method for the high-throughput synthesis of solid-state material libraries

A method that combines co-evaporation of pure elements from multiple finite-size sources on temperature-controlled substrates with independently controlled source shutters has been used for the synthesis of solid-state material combinatorial libraries. The source shutters are positioned to achieve a controlled gradient of the deposited elements across the substrate and are fixed during the course of deposition. Choice of the shutter position and the rate of deposition for each source allow the direct synthesis of continuous and controlled materials of varying composition. There are significant advantages of the method over alternatives which rely on sequential deposition and subsequent heat treatment to produce thin film materials. The parameters governing the creation of gradients have been identified and defined. Simulations and experimental data have been compared in the case of a single source. Results are presented for the synthesis of a ternary alloy library to demonstrate the methodology.     

Application of a pyroelectric detector to the study of carbon nitride film synthesis by the pulsed laser deposition method

For the first time, a fast pyroelectric detector was used to study the processes of film synthesis by the pulsed laser deposition method. The measurements were carried out under the actual conditions of carbon nitride film production. The dynamics of particle deposition and substrate heating induced by it were studied. In the double-pulse mode of PLD, efficient delivery of precursor molecules from the gas phase onto a substrate and a new pathway of CN molecule synthesis were shown to exist.     

Role of substrate wettability in the "bubble deposition method" applied to the CeVO4 nanowire films

Homogeneous two-dimensional structures of CeVO(4) nanowires (NWs) deposited on silicon substrates are obtained by means of the bubble deposition method (BDM). Surface wettability (i.e., surface energy) and film ripening (i.e., film thickness) are two major parameters in nanoparticle confinement and deposition. As the presence of surfactant could be detrimental to applications, a washing treatment is developed without CeVO(4) chemical changes or NW film modifications. Careful investigations of the film topography are carried out by atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) is used to check the chemical composition of the film at different stages. Finally, samples made by BDM are compared to those made by dip-coating method, demonstrating the higher efficiency of the BDM in providing large areas of well-organized and dense CeVO(4) monolayer.     

Simple and efficient method for synthesis of metallodeutero-porphyrin derivatives bearing symmetrical disulphide bon

A novel thiol-derivative porphyrin [2,7,12,18-tetramethyl-13,17-di(3-disulfidepropyl)porphyrin] bearing the symmetrical disulphide bond and its metal complexes have been successfully prepared by means of modification on naturally easily derived heme.The results are described by MS-MS and UV-vis spectroscopy.     

Simple and efficient method for synthesis of metallodeutero-porphyrin derivatives bearing symmetrical disulphide bond

A novel thiol-derivative porphyrin[2,7,12,18-tetramethyl-13,17-di(3-disulfidepropyl)porphyrin]bearing the symmetrical disulphide bond and its metal complexes have been successfully prepared by means of modification on naturally easily derived heme.The results are described by MS-MS and UV-vis spectroscopy.     

Simple and efficient method for the synthesis of highly substituted imidazoles using zeolite-supported reagents

Cu(II) nitrate impregnated zeolite has been used as an efficient supported reagent for an improved and rapid one-pot synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles in excellent yields. Condensation in the presence of supported reagents with operational simplicity, inexpensive reagents, high yield of products, and the use of non-toxic reagents makes this synthetic protocol, an attractive one.     

Simple and green method for synthesis of new diastereoselective spiroheterocycles catalyzed by copper ferrite

Some new spirocarbocyclic compounds with highly diastereoselectivity were synthesized using a simple, green and high efficiency method. The IR, ¹H NMR and ¹³C NMR spectroscopy and C.H.N analyses were applied for identification of these compounds. This novel synthetic approach was performed from acid catalytic pathway using CuFe₂O₄ MNPs as a nanocatalyst in aqueous moiety.     

Continuous sample deposition from reversed-phase liquid chromatography to tracks on a matrix-assisted laser desorption/ionization precoated target for the analysis of protein digests

Peptide mass fingerprinting by matrix-assisted laser desorption/ionization (MALDI)-mass spectrometry (MS) is one of the standard high-throughput methods for protein identification today. Traditionally this method has been based on spotting peptide mixtures onto MALDI targets. While this method works well for more abundant proteins, low-abundance proteins mixed with high-abundance proteins tend to go undetected due to ion suppression effects, instrumental dynamic range limitations and chemical noise interference. We present an alternative approach where liquid chromatography (LC) effluent is continuously collected as linear tracks on a MALDI target. In this manner the chromatographic separation is spatially preserved on the target, which enables generation of off-line LC-MS and LC-MS/MS data by MALDI. LC-MALDI sample collection provides improved sensitivity and dynamic range, spatial resolution of peptides along the sample track, and permits peptide mass mapping of low-abundance proteins in mixtures containing high-abundance proteins. In this work, standard and ribosomal protein digests are resolved and captured using LC-MALDI sample collection and analyzed by MALDI-TOF-MS.     

Simple nanoprecipitation method for size-restricted synthesis of aloevera nanoparticles: Characteristic analysis and its application as an adsorbent

The Nanoprecipitation method has been proved favorable to synthesize size-restricted Aloevera nanoparticles from the aloevera polysaccharide in a very simple and single step. Dropwise addition of 1% homogeneous aloevera solution (1 ?mL) to absolute alcohol (20 ?mL) resulted in the formation of 50–100 ?nm-sized Aloevera nanoparticles. The results showed that the amount of ethanol played a significant role in deciding the shape and size of nanoparticles. The synthesis of aloevera nanoparticles has been confirmed by SEM, FTIR, XRD, and BET studies. The effect of other precipitating mediums and surfactants has also been studied to analyze their effect on the size of nanoparticles. The nanoparticles are also found to be potential adsorbents of Reactive Blue H5G dye which showed an affinity for AVNP and the adsorption study indicated 95% adsorption of the dye in 4 ?h. This indicates its efficacy as an adsorbent for wastewater treatment.