Carbon physico-chemical properties

Lapidus, A., Krylova, A., Kazanskii, V., Borovkov, V., and Zaitsev, A. 1991. Hydrocarbon synthesis from carbon monoxide and hydrogen on impregnated cobalt catalysts. Part I. Physico-chemical properties of 10% cobalt/alumina and 10% cobalt/ silica. Appl. Catal. 73 65-81. 

During recent years, extensive research has been focused on the application of carbons as electrode materials because of their accessibility, physico-chemical properties, processability and relatively low cost. Carbon electrodes are thermally and mechanically stable, chemically resistant in different solutions (from strongly acidic to basic) as well as chemically inert [13-15]. 

Govers, H., Ruepert, C., and Aiking, H. Quantitative structure-activity relationships for polycyclic aromatic hydro-carbons correlation between molecular connectivity, physico-chemical properties, bioconcentration and toxicity inDaphniaPulex, Chemosphere, 13(2) 227-236, 1984. 

The central dogma of chemistry is, that the structure of a molecule correlates with its physico-chemical properties. This is usually illustrated using the correlation between the boiling point of n-alkanes and the number of carbon atoms... 

MS can measure the ratio between molar fractions of mass isotopomers. The ratio between two mass isotopomer pools of masses nti and m2 is defined in the present work as intensity ratio Jmi/m2- K identical with a mass spectral intensity ratio. If more than two mass isotopomer pools are assessed, their relative ratios, normalized to the sum, are named mass isotopomer distribution. The mass distribution of a compound can be thus obtained from the analysis of ions, which contain the intact carbon skeleton of the analyte. In the area of me-tabohc flux analysis, mass distributions of various metaboHtes have been assessed by MS. The major method used is GC/MS, whereby the analytes are deriva-tized into forms with desired physico-chemical properties such as increased volatihty, thermal stabiHty and suitable MS properties [62]. The mass of the formed derivate must be sufficiently high (usually above 175 apparent mass units) to avoid background interference [48]. To obtain the mass distribution of a compound, ions with the entire carbon skeleton of the analyte have to be present. For accurate quantification of the mass distribution of such ions, they should occur in high abundance and preferably be unique species, thus being formed by only one fragmentation pathway. 

Qualitatively, the physico-chemical properties of the various forms are similar, although they might differ in details. Most of the results discussed in the following sections are thought to apply to all mammalian carbonic anhydrases. It will be indicated in the text where significant differences between forms are known to exist. 

The polycyclic cage compounds of Group 14 elements heavier than carbon (i.e. tetrahedranes, cubanes, prismanes, etc.) have fascinated chemists for a long time because of their unique structures and expected unusual physico-chemical properties and reactivity1. It was quite reasonable to assume that such exotic compounds could possess properties... 

The tertiary enamines, in contrast to the secondary derivatives, cannot exhibit enamine-imine tautomerism. As the free bases, they exist only in the vinylamino form. Their physico-chemical properties are in agreement with this structure, especially the spectral properties. The bands due to the stretching frequency of the carbon-carbon double bond in their infrared spectra1-25-27 (situated at 1630-1660 cm-1 according to the nature of the substituents) occur at somewhat lower frequencies, but their intensities are greatly increased in comparison to those of simple olefins because of conjugation with the free electron pair on the nitrogen atom. Indications of cis-trans isomerism... 

So, our investigations allow us to establish the correlation between physico-chemical properties of the crystallization media (capillary properties of the diamond-metal melt interface, carbon supersaturation in the melt with respect to diamond) and adsorption-structure and energy proreties of the produced diamond powders. Our findings permit us to extend scientific and technological potentialities for production of diamond grinding and micron powders having unique properties. 

Complex mixtures or multi-component substances or complex substances means mixtures comprising a complex mix of individual substances with different solubilities and physico-chemical properties. In most cases, they can be characterized as a homologous series of substances with a certain range of carbon chain length/number of degree of substitution. 

P rowicz J. Influence of some physico-chemical properties of activated carbons on capacity of water treatment. Ph. D. thesis, Gliwice 1980. 

Sucrose consists of two monosaccharides, glucose and fructose, joined by a glycosidic bond between carbon atom 1 of the glucose unit and carbon atom 2 of the fructose unit (O Fig. 3). Since it contains no free anomeric carbon atom (O Fig. i), it is a non-reducing sugar. Some basic chemical, physical, and physico-chemical properties of pure sucrose are listed in O Table 3. 

Since Iijima reported carbon nanotube (Figure 9.16) preparation and its microstructure in 1991, [98] carbon nanotubes have attracted enormous attention. Because of their unique structures, these materials exhibit a variety of interesting physico-chemical properties, and they may play an important role in manufacture of nanodevices. 

Section 1 considers the methods of synthesis and physico-chemical properties of new types of inorganic sorbents (complex carbon-mineral sorbents, co-precipitated hydroxides, functional polysiloxane sorbents, porous glasses with controlled porosity, colloidal silicas, aluminium oxyhydroxide colloids, apatites). These sorbents are widely used in scientific investigations, in chemical practice and are important from a technological point of view. The presented results provide additional possibilities for the preparation of inorganic sorbents possessing unique adsorption and catalytic properties. Moreover, Section 1 presents the possibilities of the computational studies on the design of synthetic materials for selective adsorption of different substances. 

By means of the macromolecular graph, the peptide description is simplified, considering that (a) the physico-chemical properties of the amino acids are responsible for the 3D structure and the functionality of the peptide and (b) all amino acids share common structural features, including an a-carbon to which an amino group, a carboxyl group, and a variable side chain are... 

Chemical Shift Sum (CSS) was proposed as single molecular descriptor derived from spectra as the sum of the chemical shifts of the carbon atoms from C-NMR spectroscopy [Randic, 1980a]. It was shown that at least for alkanes, the chemical shift sum varies regularly with some physico-chemical properties of alkanes. QSAR models for CSS, based on artificial neural networks, were proposed by using the first four path counts [Ivanciuc, Rabine et al., 1997]. 

To highlight heteroatom characteristics, relative physico-chemical properties with respect to carbon atom are usually used. As a consequence, if no heteroatom is present, the adjacency matrix is obtained independently of the weighting scheme. These matrices are unsymmetrical because for each ith atom the physico-chemical property of the jth bonded atom is the i-j matrix element. 

Physico-Chemical Properties of Supercritical Carbon Dioxide... 

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