Synthesis pyrolytic

Figure 1. Experimental setup for pyrolytic synthesis of carbon nanomaterials in the flow gas...

Rakov, E.G. (2004) Pyrolytic synthesis of carbon nanotubes and nano fibers, Ros. Khim. J. XLY111(5), 12-19. 

STUDY OF Fe-MgO CATALYST STRUCTURAL TRANSFORMATIONS IN THE PROCESS OF PYROLYTIC SYNTHESIS OF CARBON NANOMATERIALS... 

Abstract. A chemical composition and structural parameters of specially prepared catalyst for the pyrolytic synthesis of carbon nanomaterials have been studied by X-ray diffraction, Mossbauer spectroscopy and electron microscopy. A plenty of chemical transformations in the catalyst have been monitored. The inert (Mgi xFxO) and active, very fine particles of the catalyst (MgFe204) components which are involved in the process of carbon nanofibers were revealed. 

Keywords carbon nanomaterials, Fe-MgO catalyst, Mossbauer spectroscopy, pyrolytic synthesis, X-ray diffraction... 

Transient monomeric intermediates may be formed during the pyrolytic synthesis of borazines. The pathway shown in Eq. (x) has been postulated for the reaction of ammonia with diborane ... 

One of the most intriguing applications of this reaction occurs in Scott s pyrolytic synthesis of corannulene, which is one-third of C q, from 7,10-diethynylfluor-anthene (Scheme 7.25). ... 

Pyrolytic synthesis y,d-Ethyleneketones from a-subst. allyl acetoacetates... 

S. Fujihara, Y. Kishiki and T. Kimura, Pyrolytic synthesis and Eu Eu reduction process of blue-emitting perovskite-type BaLip3 Eu tbin films, J. Solid State Chem., 177, 1032-1036 (2004). 

Most researchers were not apparently aware of earlier CNT preparations in the context of ultra-thin vapour-grown carbon fibres (VGCF). This type of CNT is termed pyrolytic (PCNT) and its preparation shows promise of large-scale synthesis. Needless to say, it is of practical importance to provide sufficient CNTs at reasonable cost. This chapter highlights the preparation methods, structural characteristics and current commercial status of PCNTs and includes a description of the devices used hitherto to obtain aligned PCNTs. By way of... 

These topics are discussed in more detail in other chapters of this text. Formally, the pyrolytic elimination of sulphur dioxide from a sulphone, with the concomitant formation of a new carbon-carbon bond, constitutes a reduction at sulphur. These reductions have been valuable in the formation of new molecules, especially macrocycles and cyclophanes, and have been reviewed by Vogtle and Rossa205. Pyrolytic elimination of sulphur dioxide has been used by Julia and co workers in the formation of mixtures of isoprenoids206, and by Takayama and collaborators in the stereoselective synthesis of vitamin D, 19-alkanoic acids207. 

For a summary of methods of radical formation, see Giese, B. Radicals in Organic Synthesis Formation of Carbon-Carbon Bonds Pergamon Elmsford, NY, 1986, p. 267. For a review on formation of free radicals by thermal cleavage, see Brown, R.F.C. Pyrolytic Methods in Organic Chemistry Academic Press NY, 1980, p. 44. 

One of the reasons for the slow development of selenophene chemistry was the lack of convenient procedures for obtaining selenophene, its homologs, and derivatives. However, Gronowitz et al.42 have reported a semilarge-scale synthesis of selenophene (10), which gives about 150-200 g ( 58% yield) of selenophene per day. The procedure is a pyrolytic reaction... 

Synthesis of (Z)-(lR)-tranH-Norchrysanthemic Acid by Pyrolytic Reaction of Chrysanthemum Dicaroboxylic Acid Monomethyl Ester with a New Catalyst... 

This approach, however, requires the absence of ill-defined carbon deposits originating from defect-induced soot formation on the surface of nanocarbons during their synthesis. Pyrolytic structures often counteract the control over activity and selectivity in catalytic applications of well-defined nanocarbons by offering an abundance of highly reactive sites, however, in maximum structural diversity. Although some nanocarbons are equipped with a superior oxidation stability over disordered carbons [25], such amorphous structures can further induce the combustion of the well-ordered sp2 domains by creating local hotspots. Thermal or mild oxidative treatment,... 

Since the pioneering work by Sarel and co-workers on the iron carbonyl promoted transformation of vinylcyclopropanes and related compounds [1], a variety of transition metal complexes have been examined to achieve effective activation of the vinylcyclopropane-cyclopentene rearrangement which usually requires pyrolytic conditions. These reactions have been applied to natural product synthesis in some cases and have already been reviewed in several excellent articles [2-4]. 

The strain of cycloproparenes is the principal obstacle that must be overcome in their synthesis. Cycloproparenes decompose usually at moderate temperatures, and they undergo ring-opening in the presence of electrophilic or metallic reagents. In contrast, they support even strongly basic conditions quite well. Accordingly, most successful cycloproparene syntheses use some base-induced elimination in the last step. Alternatively, flash vacuum pyrolytic or photochemical extrusion of a neutral fragment, followed by biradical closure or flash vacuum pyrolysis may be used. In these latter approaches the reaction conditions are neutral, and reactive products may be trapped at low temperatures. 

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