Hydrocarbon ionization potentials

Hydrocarbon Ionization potential -(eV) Activation energy (kcal mole-1) ... 

Hydrocarbons Ionization potentials (ev) Rate constants (10 k xcm xmol sec )... 

No correlation between quinone reduction potential or hydrocarbon ionization potential and complex stability. 

For radical cations a quantity, AH , can be defined, the meaning of which is close to the heat of atomization. It is obtained by subtraction of the first ionization potential, I, of a parent hydrocarbon from the heat of atomization, AHa. of that hydrocarbon ... 

In the HMO or extended Hiickel approach, the individual ionization potentials should be set equal to orbital energies. The inadequacy of the HMO treatment is apparent with odd alternant hydrocarbons (e.g., allyl, benzyl), where a constant value is obtained, in disagreement with the experiment. Streitwieser and Nair (105) showed, however, that reasonable results can be obtained with the co technique. 

Activation Energies for Hydrogenation, and First Ionization Potentials, for some Aromatic Hydrocarbons... 

For cationic zeolites Richardson (79) has demonstrated that the radical concentration is a function of the electron affinity of the exchangeable cation and the ionization potential of the hydrocarbon, provided the size of the molecule does not prevent entrance into the zeolite. In a study made on mixed cationic zeolites, such as MgCuY, Richardson used the ability of zeolites to form radicals as a measure of the polarizing effect of one metal cation upon another. He subsequently developed a theory for the catalytic activity of these materials based upon this polarizing ability of various cations. It should be pointed out that infrared and ESR evidence indicate that this same polarizing ability is effective in hydrolyzing water to form acidic sites in cationic zeolites (80, 81). 

Fig. 4 (a) Correlation of the standard oxidation potentials E%r of various alkylbenzenes with the irreversible CV peak potentials Ep at scan rate v = 100 mV s. (b) Correlation of the standard oxidation potentials r of various alkylbenzenes with the vertical ionization potentials IP. Numbers refer to the aromatic hydrocarbons identified in Tables I and III in Ref. 8. Reproduced with permission from Ref. 8. 

Ionic dissociation of carbon-carbon a-bonds in hydrocarbons and the formation of authentic hydrocarbon salts, 30, 173 Ionization potentials, 4, 31 Ion-pairing effects in carbanion reactions, 15, 153 Ions, organic, charge density-NMR chemical shift correlations, 11,125 Isomerization, permutational, of pentavalent phosphorus compounds, 9, 25 Isotope effects, hydrogen, in aromatic substitution reactions, 2,163... 

Opeida [46] compared the values of the rate constants of peroxyl radical reactions with hydrocarbons with the BDE of the oxidized hydrocarbon, electron affinity of peroxyl radical, EA(R02 ) ionization potential of hydrocarbon (/Rn), and steric hindrance of a-substituent R(Fr). They had drawn out the following empirical equation ... 

Whether or not our representation of the non-ionic chain-carrier as an ester is correct, the balance between the ionic and non-ionic forms for the system styrene—perchloric acid—methylene dichloride seems to be very delicate. Since the enthalpy terms affecting this balance must be small, and the entropy terms are likely to be important, it is not possible at present to analyse the situation in detail. However it is predictable that the factors which would favour the ionic form, as against the ester, are lower ionization potential of the hydrocarbon radical, weaker ester bond, more polar solvent, and lower temperature. 

The anions originate from the attachment of an electron to whatever electron acceptors are available in the system in bulk hydrocarbon monomer this results in the formation of radical anions. Because the electron affinities of alkenes are much lower than the ionization potentials of hydrocarbon radicals, the neutralization reaction between the cations and the anions, one possible version of which is... 

Among oxo-metals, osmium tetroxide is a particularly intriguing oxidant since it is known to oxidize various types of alkenes rapidly, but it nonetheless eschews the electron-rich aromatic hydrocarbons like benzene and naphthalene (Criegee et al., 1942 Schroder, 1980). Such selectivities do not obviously derive from differences in the donor properties of the hydrocarbons since the oxidation (ionization) potentials of arenes are actually less than those of alkenes. The similarity in the electronic interactions of arenes and alkenes towards osmium tetroxide relates to the series of electron donor-acceptor (EDA) complexes formed with both types of hydrocarbons (26). Common to both arenes and alkenes is the immediate appearance of similar colours that are diagnostic of charge-transfer absorp-... 

The second ionization potentials (e.v.) of aliphatic amines compared with first ionization potentials of the isoelectronic hydrocarbons... 

Honig, R.E. Ionization Potentials of Some Hydrocarbon Series. J. Chem. Phys. 1948, 16, 105-112. 

Farrell, P.G. and Newton, J. Ionization potentials ofprimary aromatic amines and azo-hydrocarbons. Tetrahedron Lett., p. 5517, 1966. 

Krishna, B. and Gupta. co-Type calculations on n-electron systems with incltrsion of overlap charges. I. Ionization potential of some alternant hydrocarbons, J. Am. Chem. Soc., 92(25) 7247-7248, 1970. 

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