Charged hydrocarbon species

In other words, of the initial charge of isopropyl chloride, 34% of the carbon is converted to propane under these conditions. A comparable sample of 1-chloropropane under identical reaction conditions, of excess alkyl halide Lewis acid, was converted after five minutes to the extent of 18% to propane. After 15 minutes the relative amount of "propane" had decreased as a result of further acid catalyzed polycondensation reactions. Similarly, isopropyl chloride reacts in HBr-AlBr3 at room temperature to give a gas product which is entirely propane after 2 min. In this system we again begin to see a buildup of heavier hydrocarbon species with time. The fact that the reaction proceeds so rapidly here can probably be attributed to a homogeneous hydrocarbon/acid liquid phase. This last result and additional experiments are summarized in Table IV. 

The simplest, commonly encountered, charged hydrocarbon species is the methyl cation, CH3+. Draw a dot and cross structure of this ion, and suggest a shape for it. 

Hydrocarbon species may also bear a net negative charge, i.e. they can exist as anions. Draw the methyl anion, CH3. ... 

The electrostatic behavior of intrinsically nonconductive substances, such as most pure thermoplastics and saturated hydrocarbons, is generally governed by chemical species regarded as trace contaminants. These are components that are not deliberately added and which may be present at less than detectable concentrations. Since charge separation occurs at interfaces, both the magnitude and polarity of charge transfer can be determined by contaminants that are surface active. This is particularly important for nonconductive liquids, where the electrostatic behavior can be governed by contaminants present at much less than 1 ppm (2-1.3). 

From the enthalpies of formation from Roth for the fulvenes and from Pedley for the other hydrocarbons in equations 37 and 38, we find the former reaction is exothermic by 12 kJmol-1 while the latter is endothermic by 12 kJmol-1. Ionic resonance structures analogous to 128 are expected to be of less importance for the ring alkylated species than for the parent species 103 negatively charged carbon is destabilized by adjacent... 

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