Selective alkanes

A universal system for qualitative identification was devised by Kovats some years ago. Based on the linear relation between log t R and the number of carbon atoms for a homologous series, Kovats selected //-alkanes as standards for the following reasons ... 

Aboy, M., Villa, S Riesco, N Gonzalez, J.A.,de laFuente, l.G.,andCobos, J.C. Liquid-liquid equilibria for acetic anhydride + selected alkanes. /. Chem. Eng. Data, 47(4) 950-953, 2002. 

Martinez, R., Gonzalez, J.A., de la Fuenta, LG., and Cobos, J.C. Thermodynamic properties of n-alkoxyethanols + organic solvent mixtures. XIV. Liquid-liquid equilibria of systems containing 2-(2-ethoxyethoxy)ethanol and selected alkanes. J. Chem. Eng. Data, 45(6) 1036-1039, 2000. 

Table 1 Photon Absorption and Fluorescence Properties of Some Selected Alkanes...

In Table 2, we show the room temperature x s for some selected alkanes, and among them there are lifetime data that were determined in quenching experiments. (Data for larger groups of alkanes are discussed in Refs. 48, 49, 51, 59-61, 72, and 73.) For the... 

Selected alkanes, halides (Cl, Br, I), ethers, alcohols, esters, aldelydes, carboxylic acids, sulfides, mercaptans, amines, nitrates. 

S. Ruba, B. C. Gates, P. Vijayanand, R. R. Grasselli, and H. Rnozinger, An active and selective alkane isomerization catalyst iron - and platinum - promoted tungstated zirconia, J. Chem. Soc. Chem. Commun. 321-322 (2001). 

Figure 3 illustrates the concepts of Raman cells that can be used for experiments under reaction conditions. Several commercial cells are suitable for use in combination with Raman microscopy. The rotating sample design was modified by Wachs s group (Figure 3A, Banares et al., 1994) and used to investigate supported oxides during selective alkane oxidation (Banares et al., 2000C Guliants et al., 1995 Sim et al., 1997) and various catalysts...

Table 7.3. Thermal conductivities of binary mixtures as a function of mole fraction of selected alkanes in chloroform at 30°C and 1 atma...

Table 7.6. Heats of transports and thermal diffusion ratio Kja of chloroform in binary mixtures with selected alkanes at 30°C and 1 atmb...

The conversion of butane to maleic anhydride over a VPO catalyst remains the only selective alkane oxidation technology that has achieved commercial operation. The yields of maleic anhydride vary from 45 to 67%, with n-butane conversion at 90% and selectivity to maleic anhydride ranging from 65% to as high as 97% (Scheme 16.1) [232, 245]. 

In the period covered by this edition, the hypothesis of a concerted process in the C-H insertion reaction has been challenged by a stepwise mechanism with groups both pro and contra (Scheme 1). A number of computational studies appeared applying different levels of theory on different model systems. A minireview covering selective alkane C-H bond functionalizations has also appeared <2004MI247>. 

Fig. 6.20. Critical compression ratios (CCR) for selected alkane isomers, measured in a CFR engine as discussed in Chapters 1 and 7. (After Lovell [140].)...

Research octane numbers for selected alkane fuels and predicted times of ignition [239]... 

Ichikawa M, Rao L, Ito T, Fukuoka A (1989) Ensemble and Ugand effects in selective alkane hydrogenolysis catalysed on well characterized Rhir and RhFe bimetaUic clusters inside NaY zeolite. Faraday Discuss Chem Soc 87 321... 

Control of reactivity by catalysis provides the capability to shift to lower cost feedstocks. In the twentieth century, advances in catalysis have allowed the substitution of acetylene with olefins and subsequently with synthesis gas as primary feedstocks. For example, production of acrylic acid, traditionally produced by the Reppe process from acetylene and CO, has now been replaced by catalytic oxidation of propylene. The emergence of paraffins, the hydrocarbon feedstock of the future, will depend on development of catalysts for selective alkane C-H activation (2). 

Table III. Summary of Selected Alkane Data from BLM Intercalibration Program with Santa Barbara Sediment Spiked with South Louisiana Crude Oil (/ g/g dry weight)...

Table 7 summarizes values of D[R—H] and Ep calculated from eqn. (142) for selected alkanes and olefins. For about half the examples, measured values of Ep are also given in parentheses the average deviation is 1.1 kcal mole-1 or a factor of six in rate at 25°C. 

Fokin, A.A. and PR. Schreiner (2002). Selective alkane transformations via radicals and radical cations Insights into the activation step from experiment and theory. Chem. Rev. 102, 1551-1593. 

Table 4. Phase transition temperatures (°C) of selected alkane-1,2-diols, 7a-h [78, 79]. rci=clearing temperatures of these compounds saturated with water (50 wt%), = monotropic mesophases.

Although the main applications of zeohtic sohds in catalysis will continue to be as solid acids in the synthesis and transformations of petrochemicals and commodity chemicals they continue to be considered as catalysts and catalyst supports for a range of reactions of synthetic and industrial relevance. The most important of these are of titanium- and tin-containing solids in selective oxidations. Other well-studied reactions over zeohtes include light hydrocar-bons-to-aromatics (Ga-zeolites) selective catalytic reduction of NO (transition metal exchanged zeolites) C C bond formation (Pd zeohtes) selective alkane oxyfunctionalisation with air (MAPOs, M Mn, Fe, Co) and chiral catalysis over encapsulated chiral complexes. 

Table 3 gives IP values and heats of formation for selected alkanes and cycloalkanes. It is clear that the IP differences are not large enough to render these as diagnostic tools for the analysis of alkanes and cycloalkanes. Since the IP measures the energy needed... 

The significance of NO2 and OH profile measurement in the oxidation of selected alkanes and alkenes may be seen from consideration of the generalised reaction scheme as presented in Fig. 1. 

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