Functional groups, of carbon

High quality IR spectra of different carbon surfaces were obtained by photo-thermal beam deflection spectroscopy (IR-PBDS) [123,124]. This technique was developed with the intention of providing an IR technique that could be used to study the surface properties of materials that are difficult or impossible to examine by conventional means. Recently, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) has been successfully applied to study the effect of different pretreatments on the surface functional groups of carbon materials [101,125-128]. Several studies aiming to improve the characterization of the carbon electrode surface and the electrode-electrolyte interface have been carried out using various in situ IR techniques [14,128-132]. The development of in situ spec-troelectrochemical methods has made it possible to detect changes in the surface oxides in electrolyte solutions during electrochemical actions. 

Fragments containing >C C< bonds compose the most numerous class of functional groups of carbons. However, methods for identification and quantification of these surface Ti-sites have not been adequately developed. Chemisorption of PdCl2 on powdered carbon from aqueous H2PdCl4 [54-57] can, in principle, be adapted for this purpose. This method, based on data of mathematical simulation of equilibria of PdCC adsorption on various carbon materials from H2PdCl4 solutions as well as XPS studies and eluent analysis of adsorbed Pd compounds, allows us to... 

In all potentiometric titrations, both slope and height of the pH variation determine the detectable limit of the amount and strength of functional groups. In differential curves, this is expressed by the height and sharpness of the peaks in proximity of the equivalence points. In particular, in the titration of weak acids or bases, such as the surface functional groups of carbon, at halfway to the inflection point the concentration is almost equal to the functional groups to be titrated. For example, for a base -C-OH ... 

The possible origins of irreversible capacity have been carefully studied by a number of authors. Some papers claim that lithium could be irreversibly trapped by the surface functional groups of carbon [23], e.g., by electrostatic forces such as —COO Li, or that it could react with di-oxygen or water molecules adsorbed on the carbon surface [24]. A linear dependence has been found between the irreversible capacity of a series of carbons and their micropore volume [25], and Li NMR experiments lead to the conclusion that metallic... 

A number of authors have explained this problem in terms of the irreversible adsorption of lithium ions on the surface functional groups of carbon [181,182]. In contrast, Beguin and coworkers have found high values of an irreversible capacity for materials almost free of surface oxygenated groups [183]. It was proved that the elimination of the fimctional groups from the carbon surface does not reduce the irreversible capacit>, and that the active surface area is a more relevant parameter to predict this effect. 

Ko, K.R., Kim, C.G., and Ryu, S.K. 1977. Functional groups of carbon fibers and activated carbon fibers treated with ozone. In Proc. 23rdBiennial Conference on Carbon (Carbon 97), July 18-23, Penn. State, pp. 264-265. 

Shin, S,. Jang, J., Yoon, S. H. and Mochida, I., A study on the effect of heat treatment on functional groups of pitch-based activated carbon fiber using FTIR, Carbon, 1997,35(12), 1739 1743. 

Some of the analytical methods utilize highly selective and sensitive detection techniques for specific functional groups of atoms in compounds, whereas others respond in a more universal manner, i.e., to the number of carbon atoms present in the organic molecule.- ... 

It is convenient in equations such as this to represent generic alcohols and alkyl halides as ROH and RX, respectively, where R stands for an alkyl group. In addition to convenience, this notation lets us focus more clearly on the functional group transfor-rnation that occurs the OH functional group of an alcohol is replaced as a substituent on carbon by a halogen, usually chlorine (X = Cl) or bromine (X = Br). 

A new method for achieving stable attachment of organic functional groups to carbon black surface using diazonium chemistry, has been applied to the 4-aminophenyl disulhde (APDS) precursor. ... 

Partyka, D.V., Zeller, M., Hunter, A.D. and Gray, TG. (2006) Relativistic functional groups Aryl carbon-gold bond formation by selective transmetalation of boronic acids. Angewandte Chemie International Edition, 45, 8188-8191. 

Not all drugs contain functional groups that lend themselves readily to prodrug derivatization. A case in point is the carbonic anhydrase inhibitors such as acetazolamide, ethoxzolamide, and methazolamide. Although the amino functional group of their sulfonamide moiety can be methylated, the resulting analogs... 

This conclusion is consistent with the observation that responses in mitral cells to odors applied to the epithelium are narrowly tuned and that sensitivity to particular types of odor, determined by either functional group or carbon chain length, is spatially organized in the bulb [20]. Thus, the organization of receptors into broad zones in the epithelium is further refined in the bulb, where receptors find common targets. 

The vast majority of functionalization methods of carbon nanotubes belong to two broad categories (a) covalent and (b) noncovalent functionalization of the external CNT surface. The former is achieved by covalent attachment of functional groups to the C-C double bond of the n-conjugated framework. The latter is based on the adsorption through van der Waals type bonds of various functional entities. 

The utility of the electrode to promote bond formation between functional groups of the same polarity provides researchers with an opportunity to explore the chemistry of interesting intermediates, and synthetic strategies that are based on their intermediacy [1,2], Reduction at a cathode, or oxidation at an anode, renders electron-poor sites rich, and electron-rich sites, poor. For example, the reduction of an a, 8-unsaturated ketone leads to a radical anion in which the -carbon possesses nucleophilic, rather than electrophilic character. Similarly, oxidation of an enol ether affords a radical cation wherein the -carbon displays electrophilic, rather than its usual nucleophilic behavior [3]. 

When the carbonyl group occurs within a hydrocarbon chain, the compound is a ketone. A ketone is an organic compound that has a double-bonded oxygen on any carbon within the carbon chain. The functional group of a ketone is... 

Functional groups of type E which confer electrophilic character upon the ipso carbon atom to which they are attached. 

Functional groups of type N or G (after Seebach [16],1979) that -in contrast with the type E- confer nucleophilic character upon the ipjo-carbon atom to which they are attached. 

Functional groups of type A, which exhibit an ambivalent character, conferring both electrophilic and nucleophilic character upon the carbon atom to which they are attached. Whichever character is manifested will depend upon the reaction conditions and/or the structure of the molecule to which the functional group is attached. 

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