ISSN:
0894-3230
Keywords:
Organic Chemistry
;
Physical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The substituent effect on the rates of solvolysis of substituted benzyl tosylates in acetic acid was analysed based on the Yukawa-Tsuno LArSR equation. Neither the LArSR nor simple σ+ treatment was capable of providing any linear correlation plot for the full range of substituents. The σ+ plot was not simply bilinear but widely scattered, giving a split pattern of parallel curves with significant gaps. Since any mechanistic transition with substituents should bring about a single continuous curve when plotted against an appropriate substituent constant scale, the split σ+ plot is not in line with an interpretation in terms of a mechanistic transition. On the other hand, the LArSR plots with r = 1·3 coalesced into a single smooth curye including the meta correlation curve. A different resonance demand as high as r = 1·3 is required in order to give a smooth single-curve correlation for the entire substituent range without splitting. For the reactive substituents down to p-halogens, a sufficiently linear plot can be obtained against a set of substituent constants with r = 1·3 which can be referred to the substituent effect correlation for the kc mechanism of this system. An identical r value was likewise assigned for the kc mechanism of the hydrolysis for a more severely restricted range of activating substituents down to the 4-MeS-3-CN group.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/poc.610030706
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