نتایج جستجو برای: mechanochemical reaction

تعداد نتایج: 414432  

Journal: :Chemical communications 2012
Vjekoslav Štrukil Davor Margetić Marina D Igrc Mirjana Eckert-Maksić Tomislav Friščić

ortho- and para-Phenylenediamines were desymmetrised and quantitatively transformed into mono- and bis-(thio)ureas or mixed thiourea-ureas through a one-pot mechanochemical click reaction sequence; mechanochemical desymmetrisation proceeds quantitatively without excess reagents and allows the controlled extension of a molecular structure by combining normally competing reactions.

Journal: :Angewandte Chemie 2014
Davor Gracin Vjekoslav Štrukil Tomislav Friščić Ivan Halasz Krunoslav Užarević

Mechanistic understanding of mechanochemical reactions is sparse and has been acquired mostly by stepwise ex situ analysis. We describe herein an unprecedented laboratory technique to monitor the course of mechanochemical transformations at the molecular level in situ and in real time by using Raman spectroscopy. The technique, in which translucent milling vessels are used that enable the colle...

Journal: :Physical chemistry chemical physics : PCCP 2016
Franziska Fischer Klaus-Jürgen Wenzel Klaus Rademann Franziska Emmerling

Mechanochemical reactions often result in 100% yields of single products, making purifying procedures obsolete. Mechanochemistry is also a sustainable and eco-friendly method. The ever increasing interest in this method is contrasted by a lack in mechanistic understanding of the mechanochemical reactivity and selectivity. Recent in situ investigations provided direct insight into formation path...

2014
Takeshi Ohura Yusaku Tsutaki Masato Sakaguchi

The mechanical fracture of polymer produces polymeric free radical chain-ends, by which liner block copolymers have been synthesized. A diblock copolymer of microcrystalline cellulose (MCC) and poly 2-hydroxyethyl methacrylate (pHEMA) was produced by the mechanochemical polymerization under vacuum and room temperature. The fraction of pHEMA in MCC-block-pHEMA produced by the mechanochemical pol...

Journal: :Journal of colloid and interface science 2004
Ray L Frost Erzsébet Horváth Eva Makó János Kristóf

A comparison is made of the mechanochemical activation of three low- and one high-defect kaolinite using a combination of X-ray diffraction, thermal analysis, and DRIFT spectroscopy. The effect of mechanochemical alteration of the kaolinites is greater for the low-defect kaolinites. The effectiveness of the mechanochemical treatment is represented by the slope of the d(001) peakwidth-grinding t...

2017
Anamarija Briš Mateja Đud Davor Margetić

The mechanochemical N-alkylation of imide derivatives was studied. Reactions under solvent-free conditions in a ball mill gave good yields and could be put in place of the classical solution conditions. The method is general and can be applied to various imides and alkyl halides. Phthalimides prepared under ball milling conditions were used in a mechanochemical Gabriel synthesis of amines by th...

Journal: :Faraday discussions 2014
Ivan Halasz Tomislav Friščić Simon A J Kimber Krunoslav Užarević Andreas Puškarić Cristina Mottillo Patrick Julien Vjekoslav Strukil Veijo Honkimäki Robert E Dinnebier

An experimental technique for in situ and real-time monitoring of mechanochemical reactions in a shaker ball mill was recently described, which utilises highly penetrating X-ray radiation available at the ID15B beamline of the European Synchrotron Radiation Facility. Herein, we describe the first attempts to perform such reaction monitoring in a quantitative fashion, by introducing an internal ...

Journal: :Journal of the American Chemical Society 2018

In the present study, FeAl/Al2O3 nanocomposite coating was produced on the carbon steel plate using mechanical alloying (MA) technique via a mechanochemical reaction. Stoichiometric ratios of Fe, Al and Fe2O3 as well as a substrate were mixed and milled up to 22h in a vibrating high energy mill with a 4 mm ball. Samples prepared after 18h of MA were subjected to annealing at 773 K for 1-3 h. X-...

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