Graphene radicals

So, the true relevance of the phenalenyl radical to graphene edge chemistry and physics resides in the fact that, as graphene layers grow by condensation/dehydro-genation processes, and rather than trapping n radicals as a consequence of edge sat-... 

It has already been pointed out in Section 1.4 that the MO model for polycondensed aromatic hydrocarbons leads directly to the concept of the so-called middle potential [51]. In graphite, graphene layers (Fig. 14) are stacked at a relatively large distance of 3.35 A due to van der Waals forces. These layers in an insulated form would be oxidized or reduced at the same potential, the middle potential (identical with the Fermi potential, of the solid) of —0.2 V vs. SHE (cf. Fig. 9), to form the radical cation or anion. However, in the solid, the intercalation of the counterions leads to a strong positive (negative) shift of the potential, again of about 2 V. The two main reasons for this are [128, 129] ... 

Figure 2.5 Proposed model for stabilization of carbon surfaces upon heat treatment () in N2 (inert gas) and H2. For simplicity and illustrative purposes, only two types of oxygen surface groups (pyrone and lactone) and three other types of active sites are shown. These three types are in order of increasing stability (1) type I isolated unpaired-electron sites Ar-X (where Ar represents the aromatic (graphene layer) (2) type II, Ar-C=CX and (3) type II, divalent in-plane a pair, Ar-Xs (where s represents a localized n electron). Structures C and D are formed in H2. Structure D is much more abundant in H2-treated carbons because of the higher concentration of CH2 radicals. (From ref. 84, with permission. Copyright 1996 American Chemical Society.)...

Most carbon materials behave as semiconductors, due to the k electrons and the holes present in the graphene layers, which can act as charge carriers [69]. Since the enhancement of conductivity of carbons at high temperatures is related to structural rearrangements (graphitization), the conductivity of carbons provides valuable information about the carbon surfaces. Due to the fact that the ESR is sensitive to unpaired electrons (delocalized k electrons and free radicals), it can be useful to study the chemical and electrochemical processes that occur on carbon surfaces. Despite this, only a few papers address the use of ESR spectroscopy for the surface characterization of carbon samples [59,257]. The shape... 

Addition of Carbenes, Nitrenes, and Radicals. The direct addition of carbenes, nitrenes, and radicals to the nnsatnrated ji-system of the graphene sheets can occnr throngh several reactions [Fignre 8.2(d)] [28-33,48], For example, Chen et al. [64] reported the fnnctionalization of SWCNTs with dichlorocarbene... 

Guo, W.,Yin, Y.-X.,Xm, S., Guo,Y.-G., Wan, L.-J., 2012. Superior radical polymer cathode material with a two-electron process redox reaction promoted by graphene. Energy Environ. Sci. 5,5221-5225. 

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