Scrambling entropy

Subsequent work with radical stabilizing substituents on the allyl group did not result in a 3,3-shift. " Still later, it was pointed out that not only is the 3,3-shift substantially uphill, but the tautomerization may also not occur easily in an allcarbon system so the parent system was pyrolyzed in the presence of strong base (potassium r r -butoxide), but only double bond isomerization products were isolated. Still later, labeled 4-(o-allylphenyl)-2-butene was heated at 350°C, but no label scrambling, possibly due to a reversible 3,3-shift, was observed. It was estimated that the activation energy for the 3,3-shift would be 32-35 kcal/mol if the activation entropy was - 30 e.u. (Scheme 11.59). ... 

Again, the chemist would have to spend work to undo all or part of the scrambling of the molecules. If instead, the system is left alone, chemical reactions will impact the composition and entropy ejected to or imported from the surroundings. If the chan-ist injects only A and B separately, and x moles of C are formed at the interface, then the mixing effects can be modeled via ... 

Someone once suggested that it is impossible to unscramble a scrambled egg. Describe an unscrambled and a scrambled egg in terms of the concept of entropy. 

Fig. 1 Schematic illustrations of effects of chain flexibilities on stmctural motifs and associated entropic effects occurring on polyelectrolyte complex formation. Complexation of flexible polyanions and polycations a may lead to non-stoichometric release of counterions being an important contribution to the increased entropy associated with PEC formation. Complexation of semiflexible polyanion and flexible polycation may lead to non-stochiometric release of counterions relative to the overall valence of the polycation (b). Complexation between semiflexible polyanions and polycations may yield a near stoichiometric release of counterions associated with the counterion exchange reaction in an idealized ladder-lUse structure (c). The associated structures are often referred to as d scrambled egg and e railway track structural motifs for the flexible and inflexible, respectively, pairs of interacting polymers. Panels d and e are reproduced from ref [25]with permission from John Wiley and Sons...

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